R
ob Taylor has 'reverse engineered' the C64 board and is selling his modern re-creations. They are truly a thing of beauty. Of course you can use one to replace a bad board in a C64. But you can also use one to build a new C64. Bob still has plenty of boards left in three revisions and various colours.
Why did I start this? I love using real hardware, just as I have done since '81. There's something about working directly with the actual hardware, a feeling that was lost for me in the 16-bit era, when we became more 'distanced' from the silicon.
I will always have and use all-original machines, they won't sit on a shelf to be looked at. But as a daily-driver, putting frequent stress on those old components bothered me.
We have to make up our own minds about emulation. It has its place for me but it's not the same. TheC64 is only a small step up from there (for me). I held off from the Ultimate and Reloaded for different reasons. After replacing the PLA in a black-screen 64 with a PLAnkton, that suited me really well and I began replacing as many parts as I could (non-destructively) in that 'bionic 64' machine with modern replacements; ARMSID, TOLB etc.
Making this new one from scratch is an extension of that. There have to be some compromises. At present I don't think there are modern replacements for some chips like the CIAs (maybe soon) and 6510 (again, there's a project in progress,
MockA65xx). But I have been able to buy what are allegedly 'new old stock', ie unused but real VicII and 6510. I am aware of renumbering etc. but I did buy them from one of the reputable repairers and I believe him (haven't tried the acetone test yet but will).
Options: One of the fun things about this project is making the choices. Those will be very individual choices. I've seen people use lots of pulled components, so it's more like 'replacing the pcb'. I set out to use as few old parts as possible and as many of the modern replacement parts as I can find.
What have I learned so far? Something that I thought would be fun but hasn't really been is trawling the electronics sites for the right components. Not only the right values and ratings but the right footprint too. There are 30 little suppressor caps which I got wrong footprint-wise and had to spent time trying to neatly bend the leads to fit the board. Bridge rectifiers are easy to buy, but finding one with the right footprint wasn't. Having to find and look at the data sheet for each one and check the orientation and spacing of the leads was just a lengthy slog I could have done without. (I have a better understanding of why some people re-use certain components from old boards.) Also, many components aren't available singly, so you end up spending more.
Simply buying an entire kit of parts seemed like a cheat. If I did this again I'd be tempted to do that.
(Since I first wrote this, I've discovered that Bob has provided a spreadsheet with part numbers for Mouser, and I believe that it's even possible to upload that list and populate a basket on that website.)
I made good progress. When the last of the small components were in, I was able to switch on and make sure the right voltages appear in the right places. Then I plugged in all the chips that I had, and the modern replacements where possible. The VicII and 6510 are new old stock. I'm aware of renumbering but they pass the acetone test, look unused and I bought from a well-known seller that I trust. The only 'pulls' are the CIAs and ROMs. I hope that in time there will be a CIA replacement. There are modern ROM replacements now, I'll get around to buying some of those, or buying an EPROM programmer and making some.
Modern replacements used:
ARMSID
SD2IEC (internal)
PLAnkton
TOLB
c0pperdragon's S-Video Bypass/RF Replacement
5v and 12v switching voltage regulators
I bought one of the Pixelwizard cases. These are C64C cases made from the original Commodore moulds. They come in a variety of colours and I settled on breadbin brown. Cases this shape didn't originally come in that colour, but I do like the breadbin style and the keyboard I'll use will match this case.
A friend printed me the keyboard supports. I could have bought these from Pixelwizard with the case, but I didn't know that I needed them (All the 64s I have owned have been breadbins). I even asked PW whether a k/b from a breadbin would fit this case, which they confirmed, but didn't mention the supports.
Since taking the picture above, I've been in again and re-routed the ribbon for my internal SD2IEC. That's now hidden below the keyboard and taped into place with electrical insulating tape. I didn't want to cut a slot in this lovely case, but didn't want to open the case every time I wanted to add something to the card. I've since learned how to switch that SD2IEC from device 8 to device 9, plug in my external SD2IEC and use DraCopy to copy anything over. That works beautifully, if a little more time-consuming than copying to SD using a modern computer.
That's not the end of the story:
Running dual SIDS is no problem in an emulator and I've written music for more than three voices. But there's nothing like using real hardware. These obviously aren't real 6581s but this project was all about using modern replacements.
There are a few 2-SID adaptors. MixSID, SIDFX and SID2SID to name three.
I'm going to write about this as a separate episode. The SID2SID board works and I'm using it now, but there are (unsurprisingly) some pros and cons to that board, and one of the cons has prompted me to order one of the other solutions and I'll likely change over to using that one.
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