Bartop Arcade Build Part 1

I have been wanting an arcade machine for a long time. These days there are a lot of options out there that make it easier to make your own. I purchased the Bartop Arcade plans from The Geek Pub http://www.thegeekpub.com

It has been a lot of work. I mostly used a 50 In Clamp Edge And Saw Guide and circular saw to cut out the pieces. For the arc on the side cuts I used a jig saw, and I cut them out clamped together to get a proper match. With a table saw it would be much faster. I optimized the cut layout from the original to help me get some larger extra bits to work with in case I needed it.

I essentially cut out the parts the same as the plans. In the end I found there was an issue with the Marquee Top (B) and Top Door Frame (F). The Marquee Top and Top Door Frame should have been cut at an angle to meet nicely in the back. To correct this, I shortened the Top Door Frame a bit so that it just let the Marquee Top clear it. I then also added T molding to the back side of the Marquee Top, as it was now going to be an exposed edge. If I made another Arcade, I will be changing how I end up cutting that out. I may also make some other alterations to make it easier to put in the Marquee itself.

After cutting out all of the pieces, I did sand them all on both sides. You can see in the picture above that I laid them out on top of the second half of the 4’x8′ Sheet of 3/4″ MDF. This does only take half a sheet to make this unit. One could argue that a little in that you may need more to get the blocking strips for the various corners if you use them (which I did use).

Before assembly I did use a slot cutter in a router for the T molding. I used a 1/16″ slot cutter. I took the pieces outside and use a clamp to clamp them down to my saw horse. Then it only took a couple seconds for each on to put in the slot. The biggest thing being to get the slot bit set perfectly center. The other thing, use a mask for this, it was awful the first one blew back right at me. Beyond that it is easy to put in the slot.

I assembled the unit with corner blocking, glue and brads like was done by Mike at The Geek Pub in his video. Other methods could be used, if you want you can use screws. He mentioned Pocket screws, which I do have, but I didn’t feel like trying. They are quite expensive screws and I don’t like to use them when I have cheaper options. I figured if I wasn’t careful they could split the mdf as well. If I used them I was probably going to still use glue too.. The blocking made it very easy to assemble. I was looking at trying to do it without putting in the blocking, but that made it very difficult to get good alignment. The blocking makes it stronger too with more surface area for the glue. I did have some strips of pine that I had salvaged and used them for most of the blocking.

I realized that I had not drilled for the speakers in the Marquee bottom board until after I had it installed. I used some Logitech 2 piece speakers for the arcade. Removing them from the shell, they have some 2″ speakers in them. I used a 2″ hole saw to make the holes in the board. I also had to drill for the volume control access. I removed the power Led from the board. While the board also had a Headphone jack on it, I decided it wasn’t practical to do anything with it. I needed a longer knob than the one it came with. That is also something I would do differently. Had I not already glued the board in, I would have carved out the back so I could have used a more standard length knob.

I then rewired the speakers for installation in the cabinet. I was going to reuse the original AC power unit so I setup to be able to put it in as well.

These speakers operate off of 5Volts DC. They make this speaker set as a USB Powered speaker as well so I guess it just happens to use the same board? I didn’t like the exposed AC board inside the cabinet. I went with a Meanwell dual voltage power supply for the cabinet. This let me run the Raspberry Pi and the Speakers both off of the 5Volt DC on it. It also provides 12Volts DC, which is for the Fan and the Marquee lights.

The next part was the primer. I used the recommended Rustoleum Filler Primer. This stuff is pretty neat stuff. It has a filler product in the paint. It looks like it is fuzzy, but it sands out amazing.

Don’t skip primer, It just won’t work if you are using MDF. I waited until the next day to sand it. I used I think like a 220 grit paper to take off the fuzz. I then followed up with some finer paper. From there I wiped it down with paper towels and brushed it well, then use a microfiber cloth to wipe it down. Then I painted it with some Rustoleum gloss black. I let that dry a day and took some 3000 grit to lightly sand any little bits that were in the paint. The paint I used is the 15 minute dry type to help keep the dust, bugs etc blowing into it. I found that it was better to do a single coat that caught most of the dust that got in it. Then I came back and did 2 more light coats after the 3000 grit. That later paint didn’t end up with as much dust in it. The last thing I did with the paint was a Rustoleum Clear Gloss coat. That stuff dried very fast, it was quite different and had a lot of over spray. When I was doing the painting I was mostly wearing a mask as well. I was thinking of trying to polish it, but I decided I wasn’t going to be that crazy about it, and I wasn’t sure I had the clear on thick enough. I used 2 cans of primer and about 2 cans of the black. The clear coat didn’t take even a can. I did end up with some runs on the top back door frame piece. I did use one of those spray handles for the cans. That makes it much easier for me to get a decent finish and better control. My wrist can’t handle pressing a spray can nozzle very much at all.

Well, there were two other things I didn’t get drilled before the initial assembly. The first being the “safe shutdown button” for the Pi on the back beside the power jack. The other being the USB ports in the front right there.

I had to backbore the Shutdown button here by the power port. The USB on the front nearly needed it. The USB port insert I used goes into a 30mm hole it barely has any threading with the 3/4″ MDF, but it was just enough.

The T molding isn’t too bad to do, but I wish it had went a little better. I got 20′ and I used all but about 18″ on this cabinet. There would have bee that bit more if I had not put that additional piece on the back side of the Marquee Top. I am assuming I had the full 20′ I was to have received, but I can see how it did use that much. I just did it like Mike showed in his video, back cutting at the corners, and trying to put it in strait with a rubber mallet. I had a few issues here and there. I had some problem with snagging and pulling it back out when moving the cabinet. I will be adding some feet and that should prevent it from dragging the edges too much in the future. I did put a little glue toward the ends to help hold it if it snags a bit.

Here i have the control panel assembled and the USB ports installed after finishing the Clear Coat. I am using a Dell LCD I have had around, and been using on my computer as my secondary monitor. It was almost a perfect fit, and had HDMI input and audio output (no speakers internally). The control panel layout is in the plans as well, the template prints out on multiple pages that get taped together. I used a spray adhesive to hold it on like Mike suggested. It was a bit of a pain to remove all of the adhesive after the fact ( I used a different product than he had so maybe it is harder to get off). The paper came off fine, but some of the spray stayed behind. I later used another of the templates (well 3) and was careful to use as little spray as I could, that turned out better. I used the 2 player template and omitted 2 buttons, 8 was enough for me. You can choose to use the buttons you want. He also includes a 1 player layout template. The buttons I used are the pop in kind, so with the 30mm hole they went right in a perfect fit. The small buttons I didn’t have the perfect drill bit for, so they were slightly loose, and a little glue on the bottom edge in a couple places to ensure they don’t move on me. Do drill the holes I used some Forster bits. The 30mm for the big buttons and the Joysticks, and the smaller one for the smaller buttons. They do a very nice job, the butterfly bits I have are way to aggressive, but they are a weird type. I used the bits in my cheap Harbor Freight Drill Press, which made the work go so nicely.

The one trick with the controls is they need to be wired identically, as the Pi can get confused if it has two of the same model of controllers with different layouts.

Here is the first time I fired it up. You can see the speakers in there. This was the first time I tried it out.

Here I worked on the Marquee light. I am using 12Volt White LED Strip light. I decided to build an Aluminum Light Box for it. I really didn’t have a good way to mount the LEDs otherwise, and I didn’t want all of the light going out other areas of the cabinet.

Here I am using clamps and a board like a break to bend the aluminum. It worked ok.
Here is the box. I was neater but I had it slight long and had to compress the ends down a bit.

Above you can see the LED Strip. I put it on the Sides not the bottom. This helps with Hotspots. In such a close space the points of light off of the LEDs would make hotspots all of the Marquee otherwise. The box is 1″ deep. You can also see the Speaker grills and volume knob. The Speaker grills are made from some 2″ desk grommets from the hardware store, and then covered in some speaker cloth (salvaged from an old speaker box I had).

Above you can see the back door. The door was slightly taller than it should have been, possibly a little wave and variation in my cuts for the back. The bigger thing was the that I turned out to be somewhat narrow, I am not sure if I didn’t measure properly or something. The door Frame pieces seemed to all go just fine, but there is a bit more gap left and right. So I would watch for that if I make another. I wasn’t going to use a piano hinge for it, but due to the gap that was the only way I was going to be able to hide it well. I also decided to get a lock, not that I wanted to lock it, but that was the most elegant looking latching method, and also when moving I didn’t want a “semi-secure” latch that may flip open accidentally. The holes were drilled with other templates in the plans. The bottom is the 80mm fan pattern. The top two are the hole for the suggested speakers, I felt I wanted more ventilation so I used them for additional venting on the door. Here you can also see the door once it was installed with the fan and latch assembly. The modification to the door frame top that I mentioned above did have the added benefit of adding some ventilation as well as there is a small gap there now. I like that bit of the change as heat will build up and would have caught in the top had it been sealed up. You can also see the power strip I put in there. It is wired directly to the rear power jack. I had it around and it was easy to work with. I didn’t want to buy an electrical box and wired it up that way. This is a surge protector as well, not just a power strip.

The power jack includes a switch and fuse. I like it, but some have had it has issues with melting. I could see that if the connections were a bit loose, that causes the conductors to get hot. So I can see it happening. The Safe Shutdown button for the Pi is also installed there. The button is wired up to the gpio on the Pi and the Pi is setup to use do a safe shutdown if it is pressed. It will also wake the Pi after shutdown if pressed again. I will cover that in Part 2, it is quite easy with the Pi 3.

The Marquee just has some paper in it behind the Plexiglass to test the brightness. It is a little too bright. I am probably going to dim the LEDs a bit. I am not sure how I will do that but I have an idea. That will be in another post though. So this is Part 1 of at least 2 parts.

I have to finish the Marquee, if I make a dimmer for it that will be covered in another post. I am also going to put Plexiglas in front of the monitor to hide it. Once I have the Plexiglas cut for the front of the monitor I will be able to mount the monitor in the cabinet. The Monitor I have does not have a VESA mount, so I have secured it to a built up block that I will secure with some brackets to the bottom of the cabinet. I just don’t know the exact final position until the Plexiglas is in. The Marquee top needs secured as well, but I have to finish the Marquee first. I do intend to keep the Marquee Top removable if needed, but not just friction fitted like it has been so far now. The Pi is also floating free in there. I have been thinking of pulling it out of the case and mounting to the cabinet as a bare board, but I do want to put a fan on it still if I do that. To start with the Marquee I will probably finish a design for it and reprint it on my inkjet printer instead for some color. I may get proper marquee made professionally later on. If I do, I will probably get some side graphics for the cabinet as well, but not full side covering graphics (not after the T molding is installed).

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Commodore 64 Breadbin #2 Referb : Part 1

I picked up another Commodore 64 breadbin model. It had a rough time in storage from the looks of it. The system has been in a damp dirty storage area, there were several of them being sold by the same person, in similar conditions along with some other old 80s era computers like Apple ii systems. I guess they were stored in a basement somewhere that had some real water/moisture problems.

As you can see from the outside it is a bit dirty, and some keys were missing. This was I think the second best looking of the batch. Below you can see the inside, the paper shield was a mess, black mildew along the bottom. A good bit of dirt inside. After seeing it in the bag, I decided I wasn’t even opening it inside. So I took it out back and opened it there. I removed the cardboard shield and it went strait to the trash can. The case we taken apart and hosed down to get the worst of the dirt off. I wiped the keyboard down a bit and the board before taking them in. The case parts went it the tub and got a really good scrubbing.

I removed the RF Shield and cleaned the board with some 91% IPA. It turns out to be a bit of an interesting board. Yes the screws are mostly rusty, the RF Shield and Cartridge port plate tells a tail of too much water too. On close inspection the board looks ok for the most part, the legs of some of the components are rusted, I clipped a them and the tips just fell off. This board has obviously been worked on in the past. The inner cardboard sheet that was above the bottom RF Shield went strait to the trash, it was about as awful as the upper cardboard shield.. I kind of like this brass looking shield, but without the cardboard to go with it, I won’t be reinstalling it. I don’t care enough to make a new cardboard piece.

You may notice the wires in the above picture. This is a 326298 Rev A board. An early board that only has the 5 Pin Video port. This board was built in 82 based on the unsocketed chips. The board had extensive work done to it. All of the main chips are socketed. They are all dated second half of 84. The 5 Pin Video port was replaced with a full 8 Pin Video port. There are two wires running off from that port, and various cut traces on the top and bottom to separate out the additional pins. I think in the VIC II area there were possibly some other changes. The VIC II area cage was (and still is) rather rusted as well as the RF modulator top plate, and the RF Rca port was all rusted.

So after the ipa bath I hooked up the board.

It worked, no issues. Next I tested the keyboard, it worked, minus the two broken keys. Some keys were not very responsive though. I did a full teardown of the keyboard to clean it properly.

I first removed all of the keycaps with my keycap puller. I recommend one, they are rather cheap and good insurance to prevent breaking the old plastic. I next desoldered the wires on the ShiftLock key. I had removed the tape from around the keyboard, as you can see, to get to the screws under it. After removing the screws the board lifts off, and you can see the plungers then.

I took out the plungers and put them to the side, then took the keyboard frame and sent it to the tub and some warm very soapy water. I also soaked the keys in the soapy water. Then scrubbed the keyboard and keycaps with a toothbrush and rinsed them well and dried them. I also took the springs which were dirty and some were rather rusty. I put the springs into some White Vinegar. The Vinegar removes the rust, it does make the metal a bit dull looking. I expect if you leave them in too long you may break down the metal too, so I kept checking on them. They cleaned up well, the worst of them you could tell were actually pitted but were still in working order. I then washed the vinegar off with some water and dried the spring as best I could. I placed all of that on a towel to dry properly.

While that was drying, I took some IPA on a qtip and lightly wiped the contacts on the circut board. We don’t want to remove the conductive coating. If you clean too much of it off they keys won’t work. Next I took the plungers, and wiped the shaft part with a damp cloth to get any dirt off, I didn’t wipe the contacts on the plungers, they looked pretty good. They were mostly clean overall due to being covered by the keycaps and in the keyboard frame holes.

All of the good plungers and two broken ones.

Well, I had watched Perifractic’s Lego 64 videos, and I got an idea to try on the broken plungers. They did still work, as I had tested the keyboard with them, they just won’t hold a key now.

So I found a Lego laying around. You see the full piece I started with there in the lower left. I cut it in half, cleaned the plunger up and fited it to it. I shaved it down to go into the plunger shaft a little for more surface area and strength. Then I glued it in with a combination of Bondic and Super Glue gel. I DID have to file down the Lego piece, it was too large and the Commodore Key cap wouldn’t go on it. I used my small Diamond Grit Needle Files from Harbor Freight (they are just small files, I got the Diamond Grit ones, they seemed to work well for me on plastics). I will say that the glue doesn’t hold well, these tops will come off. So it isn’t a great fix, but I think it will work. I am still waiting on replacement Plungers and springs for the keyboard. I put the one plunger back at the British Pound symbol location, but I put the other at another key that is less likely to see much use. The 8 key gets a lot of use.

Here is the keyboard frame after reassembly.

Here is the keyboard back together back in the cleaned upper case. I tested it and it all works. The * key doesn’t work very well though.. When I get the new plungers in, I will probably remove the circuit board again and check that key. I don’t know if it it is the plunger, or dirt, or the contacts on the circuit board. Other than that and the missing caps, the keyboard was quite responsive, better than my other C64. That one I did not remove the board to clean the contacts. Removing to swap the plunger and check that key isn’t too bad. I will only have to desolder the ShiftLock key and remove the screws. The plungers that I am not working with will all stay as long as the keycaps are still on the keys can’t come out.

I does look much better than it did, but it is very streaked. The Power LED plate was actually corroded to the point much of the paint was lifted and flaking off. Corroded Aluminium.. Ya, I guess a good bit of moisture for a long period of time. I plan to get a replacement Badge and maybe a matching Power LED plate, I just don’t know what I want to go with.

Next I started on some preventative maintenance as well as rust removal. I had already removed the rusty tops of the VIC II area and the Modulator top cover. I then desoldered the Cartridge Plate and the VIC II cage which is rather rusty. I did alot of cleanup on the RF Modulator cover and Cartridge plate. A combination of wire brushes, sanding, and polishing with the Dremel etc. To remove the stickers easily, I put a little WD40 on them and let it sit. When I was done they were pretty decent. I tried some Vinegar on the RF Modulator cover, but that removes the protective coating that was still on some areas of it, so I stopped that. I did soak all of the rusty screws (basically every screw in this thing) in the Vinegar to get the rust off. I also removed the Fuse holder pieces, and fuse, they were quite corroded. I placed them into the Vinegar as well (well not the fuse). The Vinegar did clean the corrosion pretty well off the Fuse holder, but it left those area black, I then polished them back to a shiny surface before reinstalling them. When all the rust was off of the screws and Cartridge plate and RF Modulator cover, I put some “Teflon Non-Stick Dry-Flim Lubricant” on them. Not to Lubricate them so much, but to put a protective film on them to help prevent them rusting again. I did the same with the keyboard springs after they were dry. I don’t use the stuff on plastics though it puts a white film on that is hard to remove. So I put it on before putting them in place.

I resoldered the Cartridge Plate back to the board. I also touched up some solder points on the board. The VIC II cage will not be going back in either. I think the VIC will stay cooler without it, and with a proper heatsink installed.

Here is the board reinstalled after cleaning up the rusty bits.

The board was tested again and still worked. So next I installed a few heatsinks.

The 5 Volt Regulator doesn’t have much of a heatsink on it. The Rivet is loose and the heatsink is spinning around. So I decided to remove it and fix that as best I could. I took the heatsink off of it. I placed it on a new 2 Amp capable 5 Volt Regulator, it wasn’t needed, but that is what I keep around. I was a little concerned that with the age and heat that Regulator dealt with over the years with that loose tiny heatsink that it really should be replaced. This time I put a second folded back heatsink behind it and bolted it on. I placed some silver thermal compound behind the new regulator and also between the two heatinks and installed it back to the board.

As far as the case repairs go, I guess I didn’t take any pictures to show that specifically. The top of the case is cracked in the front right corner, it appeared to have taken a hit to that corner. I used my solder iron on a lower temp to melt the inside together again. Then I put some liquid Testors Model glue in from the back to smooth it out. That did start to melt the plastic, I removed the excess glue. I have found that if you use that stuff and it melts the plastic and there is too much excess glue the plastic won’t harden again. The one standoff in the top of the care there is cracked as well, I haven’t fixed that yet, I think maybe from the same trauma that cracked the top. Three of the standoffs that hold the keyboard in place were sheared off as well. Those I glue back on with superglue gel. I then clamped them for a day and left it sit. That will give me the best strength, they shouldn’t be stressed while it is curing, which is 24hours to full strength. The clamping ensures they are down properly and the joint is thin and tight too. After that I believe I put some Bondic glue around them, the Bondic won’t cure in the crack because it needs UV Light to cure. I have also found it doesn’t bond very well compared to Super Glue. It does retain some flexibility and have some hold, I find that can assist Super Glue because it holds so tight, but doesn’t flex and fractures. I can’t remember, though I may have used more of that Testors liquid model glue instead on that. It is very liquid and I apply it with a toothpick to prevent it getting away, it goes into any little crack.

This case is badly discolored and I don’t want to try to retrobright it. I picked up some Krylon Fusion All-In-One Paint+Primer “Matte River Rock” paint awhile back to potentially paint a 1541 case. The case had some small chips out of the bottom. I took some Tamiya Putty “white” and filled in and built up the missing areas. It is a potent thin putty that dries quickly, and sands well for me. I it seems to bond to the case plastic well (As the model glue fuses the plastic, so I would expect the model putty to grip it well too). When I was done with the physical repairs, I put a even coat of the Matte River Rock paint on it. It turned out well. After the paint dried I found a crack show in the center of the half circle of the video port in the middle of the case. I glued that with the Testors Liquid model glue, I hope it holds well. I think once the board is reinstalled it will have more support.

I haven’t done anything to the top of the case so far except weld and glue the one crack. The one case clip on it is broken off and lost. I have not figured what I am going to do with it yet. I have thought about getting on of Birt’s “Hey Birt!” case saver kits to get a new case clip, I could use one of the reinforcement pieces on the cracked stand off, and have spares for the future. As I have to fix that case clip, I don’t want to paint the case yet, I will likely scratch up the paint having it upside down for those repairs. I will put several coats on the case. I want to test the paint on something with a Matt Finish clear over it. Some paints don’t mix well, and can cause the lower paint to lift or got to a crackle like finish. I have found that even with paints from the same company.. So I will test the Krylon Matt Finish first on a scrap of similar plastic (probably a modern computer case bezel). I want to put the clear over it, even though I like the existing Matt Finish of the paint as it should help protect it better.

So for now that is about it for this C64. In the future I will be doing more to it. The remaining repairs to the case. That include the Clip and post repair as well as painting and installing a new Badge plate. Checking out the * key, as well as installing the replacement keys and springs. I also have a capacitor replacement kit for it. The 84 Breadbin I already worked on, I found some capacitors that showed good evidence of starting to go, so I figure this one is going to be served well by replacing them. I do wonder if that especially the ones in the RF Modulator may make a difference in the video output. I may or may not install some additional heatsinks. The computer is working fine, but it does have bad jailbars, so I may do something with that too at some point. I don’t know of removing the modulator and building up a replacement would help that or not.

I would love to know where the other Breadbins that were sold with this ended up and see that they were properly cared for. There was a very interesting VIC that I would have loved to see, but I wasn’t paying that kind of cash for a VIC let alone one that looked like it spend a few years sitting in water.

Pi1541 in 1541 Case & More (Board Etching and Build) – Part 2

Well let us see. What was left after the last post. There were quite a few changes to the board layout. I found several defects in the circuit diagram I had made.

There were corrections for the Pi1541 section, in that I had connected up one of the signals that I shouldn’t have. The removal of that bit made the design a bit simpler actually.

For the Tapuino side I had several missing connections.

 

Here is the design minus the Ground connections.

The above board removes the oAtn or OUT_ATN. That line was not ment to be used by Stephen White. I also added the Buzzer for the Pi 1541 to the board design. The next changes were the missing connections to the 4052N on the Tapuino section. I was missing 4 lines going to that IC, two being ground and two to the ATMEGA pins. The other addition is Read and Write LED Indicators to the Tapuino. This revision of the design is not what I ended up making. I had made a board something like the design in the previous post. To correct it I have cut the lines to the oAtn, removed the wire from the pin on the Pi for as well. I have added wires for the missing traces to the ATMEGA from the 4052 and grounded the other two pins.

I wanted to point these corrections and modifications to the design out first. The images of the board below are the board as made with the previous design. That is why it won’t look exactly the same. The above design is the “right one”. Some pictures may show the corrections and some may show how it was originally assembled.

First let use start of with the Toner Transfer process. To do a toner Transfer you need a piece of glossy paper. I initially purchased some Toner Transfer Paper. It was rather pricey for all the more use I get out of it. With Eagle I can not find how to “tile” my printout, so I am using a full sheet for any tiny board. I found you can use magazine pages, so I tried that. It has worked out pretty well actually. The first run didn’t though. This is a more complex board, it is double sided, and it really isn’t easy to line it up properly. To do so, I printed out both sides. The top mirrored and the bottom not mirrored (as the bottom is printed mirrored already). I then lay them on top of one another and with light behind them I get them aligned. I then cut the sheets down. This gives me some registration of the alignment. I double and triple check alignment. I tape the two sheets together on two opposite edges with clear tape. I do not want the tap to overlap onto the circuit board material, so I leave a fair inch or so boarder around the board printout. If the tape overlaps the design it can make it not transfer properly. We need no assistance in having a failed transfer, that is easy enough to get without additional help.

That being said here is how my first try went.

My next attempt went much better.

With that transfer I just had to touch up some places with a sharpie in the ground plane areas. It was not easy to etch though. It took quite a few passes and pulling the board out as the toner ended up starting to lift in a number of areas. I don’t know if it was my toner, or the rather extended time it was taking in the etching solution for me. I was just using peroxide, vinegar and salt. It was taking a long time. I don’t have anything stronger here, but due to the time it took, I may try to pickup something else in the future.

Here is the completed board after etching compared to my printout samples. There is one bad short, I don’t know why it did that there. There are some areas that were a bit close. The transfer process is to put the board between the printouts, and use heat and pressure to transfer the toner from the magazine paper to the copper. The copper must be very clean and not tarnished. You want “enough” heat but not too much, too much and the toner melts and deforms, to little and it doesn’t transfer. Too little pressure and it won’t transfer. I use a small iron that I can put a lot of pressure on, but I don’t find it easy to do. Once the transfer is done (or you think it is), then put the board into some water. The magazine paper will break down and come off leaving the toner on the board. Carefully wipe it off to get that white paper haze off of the surface. Then put the board into the etching solution.

I was extremely happy to find out my alignment was nearly perfect. It etched well, although it took forever. This is the second board design I have etched, and only the third board. The first being an adapter board that was extremely simple. The other design I did, I had the traces closer together with less empty gap. The wider gap I had here between traces made it much easier to solder up as there is no solder mask present.

The next step was to drill all of the holes. That took awhile. It required some very small drill bits. I had picked up a set of very small bits from Harbor Freight last year for very little cost. They turned out to be perfect for the job. The only problem is it would have been forever with my pin vise drill. I went to the drill press (from Harbor Freight as well), and well it couldn’t hold bits this small. Well my pin vise drill is metal, and round if I take the bottom piece off. I carefully installed it into the drill press chuck. I tightened it just enough to hold it and left the other bit holding part inside the shaft of the pin vise to make it stronger.

I then went ahead and drilled out all of the holes. The smallest being the holes for the resistors and capacitors. The last board I did, I drilled some of the holes a bit large, that made it hard to get the leads to solder in with too much gap around them. This time I went with the closest size bit I could. That ended up being about 3 primary sizes, the smallest for the resistors and capacitors, then one for the Dip sockets and finally the pin header and other connectors. With a few larger ones for the mounting points on the PS/2 style socket and board mounting holes.

With this being a double sided board, and no plated through holes I had to pay special attention to assembly. I used Machined DIP Sockets for the ICs, as the top side of the pins can be accessed with them tight to the board, and some of the connections are only on the top of the board. I didn’t have a Machined socket for the ATMEGA so I used machined strip headers for it taking care to make sure they were standing up strait. I did not assemble this board in the order I would if it had been a manufactured board with proper through holes. Normally you would put in the short stuff first then the taller stuff later and the tall connectors last. Well I couldn’t do that and get to the areas I needed to on the top side.

As I mentioned above there were some changes to the board after I etched it. The above image shows it as it was made initially. Below here is the revised board with the corrections. The removal of one resistor in the Pi1541 area, I also removed the one header by the Serial port due to there having been a short under it I had to remove. I didn’t need that header in there for my exact use. That header would be used if you wanted to put in a Second Serial port like the real 1541 has instead of the PS/2 type port I am using for my 7″ LCD interface. The same header coming off the PS/2 port wires to the removed header above the Serial port to enable it in that case. The cutting of one trace in the Pi1541 area by that resistor on the bottom side of the board. The additional two wires for the Tapuino between the ATMEGA and the 4052, as well as the added. Ground pins connected up to it. Again the below changes don’t need made to the “newest” design. These modifications are due to the earlier defective design I etched this prototype from. If you compare them there are quite a few changes between it and the revised design at the top of this post. This is how the board is in my drive now though. I have the Pi Buzzer for the Pi1541 directly on the GPIO of the Pi. I don’t have the Read and Write Status LEDs for the Tapuino, although I am thinking of adding them. It is worth noting that the pinout for the header that is going over to the Pi’s GPIO is different on this earlier board than the revised board. The changes were for one to move the Buzzer to the board, but also I swapped the positions of two of the signals to simplify the traces going to the Serial port.

Here I have the board installed into the chassis.

I had mentioned in the last post that there was an issue with the Meanwell power supply needing a 200mA minimum load on the 12Volt rail. My solution to that problem was to install 2 100mA rated fans. The one I put on by the little audio amp. The ic on it gets warm at higher volume levels, so I figured it was a good idea. The other fan I put on the top of the case by the Pi to cool it. The fans make very little noise and provide enough load to the power supply to be happier. I don’t believe the fans are are really pulling 100mA but they are close enough that everything seems to be working well.

Yes the Pi1541 is working.

Here are some shots of the exterior of the Pi1541/Tapuino unit.

The Tapuino section is also working for the most part. There is another defect on the ATMEGA socket on the board I etched which is also correct in the design at the top of the page. I couldn’t get the Tapuino to work with the 4052 installed. So I bypassed the 4052 with some jumpers into the IC socket and have been using it that way. I gave up one night and after that I found what I believe to have been the problem. I think I have it all right now, but I just need to put the 4052 back in and retest it. The problem is I really don’t feel like taking it apart at the moment. I expect I will get around to it in the next week or so though.

I plan on making a third part to this series of posts to cover how my testing with the 4052 goes, and covering the other things this unit was put together for.

I would like to post the board design in some way that it can be downloaded by others that may want to try to use it. I don’t know about making Gerber files though, I could post the Eagle files somewhere and then someone could do Gerber files themselves. Eagle is free for these small designs.

Referbishing a Commodore 64 326298 Rev A 1982(FAB 326295 Rev D)

I picked up another Commodore 64 quite cheaply. This poor system had been stored in some bad conditions. I am not sure the conditions, but it had been wet at one point at least and damp quite a lot. When it was put there, it was probably pretty rough looking as far a browning of the plastic. This was an early Commodore 64 from 82 originally. Oddly the serial number label had no serial number printed on it. I have seen some labels that ink can be removed from by some cleaners, so I don’t know if it had been wiped off or never had a number.

Internally it as all there. The old paper foil shield was dirty and had mold on it. There was dirt and dead bugs all inside it. The first thing I did was pull the paper shield and toss it out, I then pulled the keyboard and mainboard out. Next I hosed the worst of the dirt and bugs out of the case with a hose.

Next I removed the bottom shield from the mainboard. It showed quite a bit of corrosion on it.

Before I tried to fire the board up, I did a bit of cleanup on the board itself. Then I looked it over to see if anything needed addressed before trying to power it on. I first checked that the power switch was making good contact. I then checked the Fuse was good. I also pushed all of the socketed chips in to make sure they were tight.

Looking over the board it was dated as 1982. There are some odd things about this board, it has had all the main chips socketed (all “wide” chips). The main chips are also all dated 1984. Three of the ram chips have been replaced and are also dated 1984. The remaining chips are all from 1982.

Here you see all t he main socketed chips. CIAs, the 3 Roms, the CPU, SID, PLA and VIC II from 1984

The next odd thing about this board is that it has a 8 Pin Video Socket instead of the 5 Pin Video Socket that was originally on it. julrod over at Lemon 64 said he had heard that Commodore service centers had upgraded the 326298 boards with 8 Pin Video Sockets. I have yet to test if the 8 Pin socket includes the added Chroma signal for S Video like video output. Looking around the 8 Pin Video socket I saw 4 cut traces (some on the bottom some on the top) around it and there are two wires on the bottom side leading off to points on the board.

Here are the two wires off of the Video Socket, you can see some of the cut traces too.

I connected the cleaned up board to a display and my power supply. It actually came up to the normal startup screen showing all of the memory. The video was noticeably poor compared to my other later Commodore (a 1984 model). It has bad Jail Bars on the screen for one. I then connected up my full test harness an test cartridge. The board passed all of the tests. I fired it up with my Pi1541 and started up a game.

The next day I spent doing a lot more cleaning of the computer. The case was cleaned with some CLR Mold and Mildew cleaner, a brush and a toothbrush. It still looks bad due to the lack of the badge, the bad browning of the plastic. The plastic is streaked oddly in the browning as it isn’t very uniform. The top has a crack on the right front corner. Three of the mainboard mounts are sheared off. The narrow right tab is missing that holds the back on. Two keys are missing and the posts are broken on the keyboard. The keyboard worked, but it wasn’t very responsive. It is quite dirty as well of course.

Most of the screws are rusty. Some of them are very badly rusted, anything in the “front edge, including the base screws. I put them into some vinegar. After soaking in it for awhile, the rust was removed from them. It left them looking a bit different, but they were in much better shape. I also did the same with the keyboard springs.

I removed the cage around the VIC II area. It was quite rusted, and I don’t like them anyways, as it makes it hard to get to the parts inside. It may be a decent heatsink for the VIC II though, I replaced it with a real heatsink though. The computer has a factory mistake where R10 by the VIC is 300 Ohms where it should be 120 Ohms. Ray Carlsen recommended putting in a 220 Ohm resistor in parallel across the existing R10 to bring the resistance to what it was supposed to be. This corrects the resistor in at R10 brings the strength of the Composite Video output to what it should be.

Here you can see the new Blue 220 Ohm resistor stacked on the original R10 just to the right of the VIC II

Here is the keyboard disassembly.

I lightly cleaned the keyboard pcb with some IPA. Once it was put together again, it did seem like it was more responsive. I haven’t tested it fully though. Keep in mind that too much cleaning of the contacts will rub the carbon off and they won’t work properly.

For the keyboard I turned to a little inspiration from Perifractic at Youtube. I had to tear down the whole keyboard to clean it properly. It also wasn’t making good contact on some keys, so I decided I would clean the pcb on it. I don’t have spare keys, or posts. I decided I would try repairing the broken keyboard posts with some pieces of Lego Cross posts. It does look like it may work, I don’t know for how long though. The one key the “pound” key is one that I doubt I will end up using, so having a repaired post there shouldn’t be a big deal. The other key was the 8 key so I decided to move that post to another position where it will get less use. To do this was a combination of a drill bit, using a Dremmel, and Xacto knife. While the Lego Cross axel looks like the key post top, the problem here though is that it is just a bit too large. A Lego piece that accepts the Cross Axle will go on a Commodore Post, but a Commodore Key won’t got on the Lego Axle. I don’t know if some of the Lego Axles are a little different or what though the ones I had wouldn’t work with the keys properly. I ended up using a small file to file them down to a more fitting size. I found that superglue won’t get a great bond on Legos, Bondic doesn’t either. I did try some model glue, which was said to be able to fuse Lego pieces. I don’t know how well it is holding. I may eventually replace the damaged posts, but for now they are hopefully ok. I still need to get 2 springs and two keys.

I reassembled the keyboard with the repaired posts.

I also took the top off of the Modulator and cleaned and polished it up. The plate on the Cartridge Port had some bad rust on it as well. I desoldered it from the board so that i could get it properly cleaned up. They both turned out to be a good improvement. I was going to paint these pieces but decided not to. Instead I put some teflon liquid to try to protect them from rusting quickly. I also used it on the screws. It puts a bit of a coating on stuff and is used to protect tools from rusting as well. The other part/parts I pulled to clean up were the two parts of the Fuse Holder. They were badly corroded. I desoldered them and polished them.

The board now looks quite better. I also installed heatsinks on the VIC II, SID, PLA, and CPU.

The conditions left the metal plate around the power LED corroding and the paint lifting off. I ended up cleaning it as best I could. I have to figure out what to do with it for painting etc. The main case badge was missing, and from the condition of the browning of the plastic , it must have been missing for a good while.

In an effort to get the old case looking a little better, I scrubbed the case with a paste of Baking Soda to get some of the marks off of the plastic. It did get rid of some of them. The plastic is still streaked brown.

For the crack in the right front corner on the top, I melted the plastic from the inside with my solder iron set to a lower temperature. This held the part in place, but for the crack on the outside, I used some model glue, that seems to have fused the plastic there pretty well. I also put a little on the inside to even out the melted plastic. Be careful about getting too much of that stuff on the plastic, it will dissolve it making it soft. It may not harden properly again if that happens.

Some of the pins in the components were rusted, and rusted badly on the bottom side. So I thought I would just clip them closer to the board. When I clipped at least two of these they just came right off. They were rust clear to the solder. I don’t think they were rusted below the solder. I tried to remove as much rust as I could. The presence of rust encourages the formation of more rust unless I am mistaken in what I have heard.

So far restoring this old beat up 64 has mostly been a lot of cleaning and some physical repairs. I did do the R10 fix. I still have more to do with it, and I am not sure when I will find the proper replacement keys. I was thinking of just ordering any key to put on the keyboard so I have a full keyboard, but I am not sure yet. I will probably recap the board. I have to fix those 3 board mounting standoffs that are broken off. I may fix the broken case tab on the right as well. The heatsink on the 5 Volt regulator is a bit loose, so it won’t be making the greatest thermal transfer to it. I will see about fixing that up before using the computer too much as well.

I am looking at the options for replacing the case badge. I also plan to paint this case and not to try and retrobright it or anything like that. The letters on the keyboard keys are also yellowed. On the left side it isn’t too bad, but as you go across the keyboard it gets quite bad. This computer will never be the best show piece. I think I like it though for the 8 Pin Video on the early board, and the main chips being socketed. I could easily use this board to test most of the typical breadbin primary chips. Being is such poor physical shape gives me a bit of freedom as this case will never be “like new” again, I can do what I want and not have to feel like I am harming it. It is a bit unique and it will remain so. I didn’t check the Chroma output on that 8 Pin video port yet, but I will get around to that probably later this week.

Once I was done cleaning it up, and I finally put the keyboard back together I fired it up again to try out a game again. I “think” it looks a little better onscreen. It still has noticeably worse jail bars than my other Commodore 64. I am only using it on my little 7″ composite display so I don’t know how bad for sure until I put it on a bigger display.

As I make progress on the restoration of this Commodore 64 I will probably do a followup post on it.

Pi1541 in 1541 Case & More (Bare Tapuino, Audio & Composite LCD power) – Part 1

I am looking to put a Pi1541 in a spare 1541 case I have. It seems a bit roomy for such a thing. So I am looking to put some additional items into it. 

I plan on putting in a Tapuino (Bare Tapuino). The controls for the Pi1541 and the Tapuino will be installed into the 5.25″ drive plate. 

I also have a 7″ LCD TFT display, commonly used for Backup Cameras in cars I guess. I have shown it in my other blog posts here when testing the C64. The LCD runs off a 12Volt supply, it typically shows that it is drawing around 250mA of current at 12Volts. I have picked up a MeanWell dual voltage power supply. It has 2 inputs, so I will be wiring it to the Pi as one input and to an external port to have it connect to the C64 etc if I like. The harness that it came with has a PS/2 type connector, so I will put a pass through in the 1541 case to allow easy disconnect.

I am looking to also put in a small mono audio amp with control on the 5.25″ plate as well. The amp will have an input in the back of the case to accept input from the C64/128 etc. It also has a switch to get the audio from the Pi instead, I don’t recommend flipping the switch with the C64 connected and powered up though. Also the C64 etc should always be OFF when plugging or unplugging it, as well as the device it is plugging into for safety.

Power will be handled by an internal MeanWell supply or two, using the original power connections and switch off of the back of the 1541. 

I am mounting the Pi above the power switch with the USB and Network port accessible. I also want to make the HDMI accessible too. The Pi’s card slot will be extended to the front of the 5.25″ plate to aid in swapping the cards. 

I figure if the Pi’s ports are accessible, and the card slot. I can easily swap the card and run other things on the Pi. That is if the gpio connections wouldn’t cause a problem. 

I am going to design a board for the main Pi1541 circuitry as well as the Bare Tapuino and LCD connection. I am not sure of my ability to make the board myself. I was originally going to go with a single sided design, but it ended up getting more complex. While I possibly could have still done it with a fair number of jumper wires on the other side, I think it would have just been to messy for my taste. If I can’t make the board, I may look at ordering one from one of the pcb manufacturers.

Here is the first mockup of the front Panel. The Pi1541 and audio volume control for the audio amp is on the left, with the Tapuino controls on the right side. This was before I started cutting the mesh panel for the controls.

Here is the panel after I got it all cut out. I did put fresh coat of black paint on it. It wasn’t the most fun to get correct. The LED holes are slightly off, and I have adjusted the leads on the LEDs to shift them a little. The buttons seem to work well, and the LCDs are fine. The holes were done with my cheap Harbor Freight Drill press. The LCD and SD Slot openings were done with the Dremmel and a cut off wheel mostly.

The Tapuino is based on the Tapuino design that has the option to do tape copies with another cassette or cassette emulator. My unit won’t have that connected up, but I figured the design should have it. I couldn’t find the 1.7? schematics that include addtional status LEDs as well as a buzzer/speaker. I am not sure I want the buzzer, although it was neat idea I guess, and I don’t need the status LEDs, I have the LCD which shows the status fine.

I am building the Tapuino with a bare ATMega instead of using an Arduino Nano or Pro Mini or such. I have partially built up the Tapuino on an Uno, and on the Bareduino for some testing. I should really finish building it up on a breadboard to verify it actually works before etching the board though.

Here is one of the latest designs for the board printed out for fit testing. You can see the MeanWell supply there at the top left. I did mount the supply close to where it is sitting, but I did turn it to get acess to the ports, and also have metal to get it properly screwed into. The Raspberry Pi is mounted there to the left. I used some M2.5 salvaged screws and a metal plate. I used salvaged heavy wire insulation as custom height standoffs for the Pi. The screws pass through them tightly and it keeps the board from getting down on the metal plate below. The plate is mounted to the holes where the regulator heatsink had been mounted to the frame. That lets the Pi get good ventilation as well being at the vents. I retained the original power jack, switch and fuse and run that into the MeanWell supply. When I did the mockup fitting I found the design (laying there to the left of the case) that I had was over too far. I squeezed it down a little. While it cleared the Pi pretty well, it would have interfered with my SD Card extension. You can see the little bit of of white strip there going under the fake circuit board. It is also that wider white flat cable going up past he power supply. The latest change to the board is I have extended it and put the mark in for the third screw in the upper corner.

Here is where I started putting in the openings for the port on the Pi. I started by drilling the holes near the corners. After that I largely used the Dremel to open the bulk of the holes. For the finer fitting I used a fresh Xacto knife and some small hand files.

I was very happy that I was able to leave the posts between the ports and that I didn’t have to open them up with gaps between them. So here is the side of the case with the Pi in it when I was basically finished with it. There you see the Network card and USB ports opened into it.

I have mounted a HDMI extender as well, that is in the lower portion of the case.

Here is the front panel installed and the Pi1541 powering up. I have the audio amp off, and the Tapuino isn’t present inside. Also the Tapuino is powered by the C64 Cassette port anyways.

Here is the additional rear port for the Tapuino. It is a 6pin Din to a C64 Cassette edge connector connector. The cable is an old Cat5 Stranded wire cable which is very flexible and actually nicely durable. The shell on the Edge Connector is a DB15 shell that I had to work the holes a bit to get aligned well enough to get screwed in.

Here is the custom cassette cable.

Here is the current state of the back of the case. The left RCA port is the Video IN for AV2 on the LCD Monitor output. The red jack is the Audio in for the internal speakers, with the switch beside it to switch between that jack and the Pi for Audio. The Pi Audio is mixed with some 470Ohm resistors to prevent damage to the Pi as I am mixing the Stereo inputs down to Mono on it. The wire there in the one old Serial port hole is the PS/2 like connection for the LCD Monitor. I am using a temporary cable I made up for that until the board is etched though. The last thing I am thinking to add is a Reset button for the Pi. I didn’t put one on the front, for one there is not much space, and I don’t want to accidentally hit it.

The Pi is intended to have the card swapped and be used for other things. So for other setups I plan to take and setup one of the front buttons as a Safe Shutdown button. Then the Reset button on the back would be the power on button to wake it from that state.

Here is another shot of the monitor on the Pi1541 powered up.

Without the custom board, the Pi1541 isn’t complete and the Tapuino doesn’t exist except the control panel though. So here is the internal as it is setup awaiting that. I have most of the wiring done, and the header cables made up now.

Here I have removed the Pi. I needed to install the header to the Run pin on the Pi. I had wanted to show the mounting bracket a bit as well. So that made it convenient. The Pi is fully removable by unplugging cables and taking out the 4 screws. In the picture you can see the HDMI extender there below the plate as well as the hole in the plate that lets the heat sink on the bottom of the Pi to come through it. The 4 small holes in the plate are where the Pi screws in. There you can see some although maybe not all of the various headers. The long on on the left being the Tapuino port cable. I really wanted to leave enough to get the case open safely. The headers are not keyed(blocked holes), so I want to be able to easily double that I have connected them all up correctly without fighting the cables. You can see the little speakers mounted up where the old physical drive was. The speakers were salvaged from some old unknown laptop years ago I believe. They were stereo speakers, but as my Amp is Audio, and it was happier driving them in series than even a single one (too much power was going to burn up the little tiny amp). So they are wired up in series to lower the overall output, but driving both speakers at once. The little mono audio board is there as well. The little black thing on between the speakers there with ROHS on it is an ground isolation device, because the Pi and the audio amp were on the same power supply I was getting some interference.

Here I have reinstalled the Pi after putting on the little blue header pins for the Run connector. You can see the 12pin connector that will goto the Pi1541 section there. You can see the temporary PS/2 type connector that goes to the LCD laying below the case, the proper connector is already on it, so that it will just plug strait into the circuit board when it is ready. The three sets of wire that will goto the Tapuino section are there as well, the flat ribbon from the SD card slot, then one for the buttons and one for the LCD although the ends of them are obscured.

Here is the Pi header. I didn’t have a header that was large enough to connect it all up in one piece. The remaining pins are not being used. Some go off to the front panel, the smaller wires blue and white and one red one on the second 5Volt pin. The others are going to a 12pin 6×2 header that will then plug into the Pi1541 board that I haven’t created yet.

I have run the audio from the Pi for a good burn in while running in Linux playing some Youtube videos. If I turn the audio up to where it is nearly distorting it does start to get very warm. So I probably will have to watch that I don’t overdrive it and burn it out, but if I keep the volume reasonable it should be just fine.

Here is a shot of the latest board layout. I just did some work on it last night to extend it up for the third mounting hole there. There are some other minor adjustments compared to the paper printed mockup shown above. The Tapuino and the Pi1541 board are completely independent but just on the same board. You can see the DRV LED header there in the upper right. That header is to goto the original Green drive LED on the case front. It will be an always on light when the main power switch is on.

With the free version of Eagle it limits your building area, so that is at the extreme top edge of usable board area in the free version. If I could have put it at the extreme top I would have though. It is also right at the far right edge as well. You can extend the board itself, and you can put Text on the extended area, as well as that through hole mark for the screw. There is a little room to go further left, but I think the bottom is about as far as it can go down. It is a little trick there with Eagle to find your edges.

If you look at the Pi1541 section, you will see some additions based on Steve’s Wiring Diagram for the Option B hardware. I while haven’t seen any boards using those additional signals he said that it would work with the current firmware, and that it is for some later additions.

I guess I will need to work out the Pi Reset/Restart button location and wiring and testing. I then also am thinking of painting the plastic case as it is a bit oddly discolored. and has some writing scratched into the one side. I figured on filling in the scratched on letters, and then painting it. I want to save that for a bit later though, so there is less risk of damaging the paint while building it still. Also if you look at the pictures you may notice things like the external Audio and Video jacks are not yet connected up. That is due to the interest in painting the case before installing them permanently.

I also have not yet worked out the issue in that the MeanWell supply I picked up needs a minimum load on the 12Volt line. I did try with a load resistor, and that worked, but it is wasteful, and generates that much heat 2.5Watts? I don’t want to introduce the heat inside the case. I would then need a fan, but I was thinking if I would want a fan, why not just get a fan that would use the current itself. I did have a small 12Volt fan that uses 200mA of current, but it was way to loud. The way I have been using it so far though is to always have the LCD connected up. That puts sufficient load on it, but my intention is for the LCD to be optional and not always connected.

I will post an update once I get the board made up. I may post another on testing though if anything interesting comes up.

Commodore 1541ii Replacement Power Supply

My 1541ii didn’t come with a power supply. I initially tested the drive with some pins on power leads from my variable power supplies. That worked to test that it was functioning. It certainly wasn’t the best way to use the drive long term. I had a MeanWell dual output 5Volt and 12Volt supply I picked up for another project and had ordered in a 4pin Din connector. The next time I used the 1541ii drive, I had wired it up with that drive. Well right as I started using it the drive failed on me (see prior post). It turned out the SRAM failed for some reason. I don’t know if it had anything to do with the MeanWell supply or not. That supply requires a minimum load on both outputs for it to work properly. I don’t know if it wasn’t getting that load and was sending the wrong voltages to the unit.

After that I went back to using my regulated variable supply for the 12Volts and a 5Volt fixed bench supply I have to test the drive from there on. The MeanWell is intended for another project, but it my not be used for that project either as I don’t think I will be providing the “minimum load” on it.

I decided to order in a used dual voltage power adapter from Ebay to become the new supply for this drive. The one I picked up is 5Volt 1.5Amp and 12Volt 1.5Amp. So it is more than sufficient for the job, provided the quality and condition of the unit is good.

The supply I picked up to convert for the 1541ii

All I really needed to do was cut off the existing 4Pin Mini Din connector and replace it with a properly wired 4Pin Din connector. While I could have purchased a cheap new supply and done the same thing with it, I felt this “old” supply was probably going to be better quality than the cheap replacements. It did come in looking a bit dirty like the picture above, but it cleaned up well and tested fine.

Here is an image of an original supply. Notice the Pinout there. Only 3 of the pins are used on the 1541ii Supply. It is said that the ratings on these original supplies were rather low, potentially causing them to overheat and be unreliable. That sounds a bit like the original Commodore 64 supplies now that I think of it..

Image of an original supply.

Here is the supply with the connector changed out.

While I don’t normally wire the “ring” of the Din Connector up to anything, I did wire the second ground to it as it was a convenient way to keep it out of the way, and I don’t know if that 4th pin goes to anything inside the 1541ii. I probably should have taken pictures of the connector before closing it up.

After soldering on the wires to the pins in the Din connector I insulated all the pins and wires with Liquid Electrical tape. It has a bit of hold to the wires, but mostly is to help prevent shorting in the connector in case a wire pulls loose. There isn’t much room in there to get normal heat shrink on the pins, as it is best to keep the casing to wrap the clamp part of the connector to. I did the same thing with the Commodore 64 power connector, and my new video/monitor cable.

I did put a piece of heat shrink on the cable under the strain relief cover of the Din plug. That piece of heat shrink builds up the end of the cable just a little and makes the strain relief bit grip well. Without it, that relief tends to pull back easily and will likely tear prematurely. I have done the same thing on my Commodore 64 Power Supply’s Din plug. I wish I had done it with my new video cable I made. My old original video cable could have really used it as well, but I don’t want to take apart the connectors and redo all of the soldering on them. There is a bit of risk in damaging the Din plugs as they melt easily when the heat is applied to solder and desolder the wires.

The supply seems to work fine with my 1541ii. The Din Plug quality is rather lacking though, I think it will hold up ok, but the fit isn’t the nicest.

1541ii Repair. already..

Watching some videos, I noticed the 1541II had a grounding wire going from the one screw on the mainboard up to the right side of the drive assembly. I happened the have a braided ground cable of approximately the proper length that I salvaged recently and was on the bench still. I cut it down a bit and soldered a second lug to it and put some heat shrink on that end. The original one that I saw was not insulated, but as this one was already covered in heat shrink I figured I would leave that. I also picked up some new 10uF 25Volt Panasonic Electrolytic caps with my last order from Console5.com. I figured I would swap out the 3 original capacitors on the board. I went ahead and replaced the capacitors and reassembled the drive with the additional of the grounding strap. I had rigged a Meanwell dual voltage power supply with a power cable for the drive and figured I would test it out. I fired up the Final Cartridge III+ and brought up the Disk utility and checked the status of the drive, it came up normally. I attempted to read the disk and it failed then it started blinking an error. I turned it off and reset it and then it only blinked the light with a somewhat slow blink and kept turning the drive.

I rechecked everything, made sure again the capacitors were installed correctly, that nothing had shorted. That the power supply was supplying the proper voltages. I swapped the VIA chips. The board is fully socketed, so I removed and reinstalled all of the chips. I used my IC identifier on all of the 74 logic chips and they all read fine. I don’t know if that IC checker is just an identifier, or if it really checks for proper operation. I also tried both in normal mode and in JiffyDOS mode.

After all of that I also tried powering the drive with my fixed 5 Volt linear power supply and my variable regulated supply set to 12 Volts. The same results pretty much every time. I did a search and couldn’t find anything on that issue. So I had done all I could, I went to the Lemon64 forum to see if I could get any feedback on the issue. Someone pointed me to Ray Carlson’s 1541II troubleshooting text file, and after reviewing it there was a reference that the issue may be the SRAM and if not that the next would possibly be the DOS Rom.

The SRAM socket was an ugly thing so I figured I would start replacing it. I pulled that cut up socket and installed a new old stock one I had around. That didn’t fix the issue though.

Here is the old “socket” (for U5) after removing the solder. The socket for the 7406 (U7) is also desoldered. That socket was not seated flush to the board and was leaning toward the U5 socket making it just a bit too tight a fit. I put it down flush to the board like it belonged.
The board after removing the socket.
New Old Stock socket on the left and the original “socket” on the right.
Here is the new socket installed for U5 before putting the chips back. Yes it seems to be a gold plated socket.

Next I desoldered the SRAM chip from my spare 1541 board as it is the same type of chip on it. I installed the salvaged chip and the drive worked. Well it quit blinking constantly.

I then assembled the drive and connected it back to my Commodore 64. I went to check the status and it came up normally. I went to read a disk and it just error blinked. So I took the top back off of the drive, it seems the head wouldn’t move under it’s own power. I checked if it was free, and it would move with the power off, but there is some resistance. I don’t know how free it should normally be though. I then used the Alps drive test built into the Final Cartridge III+ to move he head around, it moved out but it didn’t move back the first time. The next time it did move back. I tried a few times and then I put in a disk. I was then able to read the disk normally. I read a few of the programs on it and it seemed to be working again.

I am going to get some silicone grease put on the rails to keep them freed up. I hope this drive will keep on working properly now. I am on to getting a proper power supply wrapped up for it as well.