| Posted By
RetroAndMore
on 2024-07-17
02:39:36
|  Hardware project for C16 and C128
Hello,
I have plans for a hardware project. It was originally designed for the C128, but it is also well suitable for the C16. I'm not planning a version for the C64 or the plus/4.
There are actually lots of hardware projects for the C64, but they are all FPGA-based. For me this is 'not the real thing'. They are also way too expensive while getting too less new functionality. The C64evo is $1400 for something a regular C64 can do. The MEGA65 is half the price and can do a lot more, but nobody will use this machine because it's no standard.
I only have real 90's hardware. Two CMD HD's, an FD-4000, but no SD interface. I also own the SuperCPU 128 and the Flash8, so I know their problems. So I made a plan for an C128 hardware upgrade.
- 99% compatibility to C128 mode, 98% to C64 mode
- PCB with only a few SMD components, designed to be soldered by yourself
- no programmable components like FPGA, CPLD, GALs or PALs, only off-the shelf parts
- cheap: About 50 to 60 Euro for the IC's
The C16 version can use the same electronics, but it should get two additional components: A SID and a VIA. This combination allows a userport and a third joystick port with mouse support. Adding a VDC is also considerable, the 8563 chips are widely available and this would increase the compatibility between the two boards. The electronic schematics are already existing, they are using only 65xx and 74xx chips. There is only somebody to put these together and create a PCB from it. The special effort for the C128 version is to make it as flat as possible, but I have ideas for this. The SMD IC's have to be soldered during production, I guess it's four for the C128 version, three for the C16 version.
It sounds like a one-person-idea, but it isn't. I'm no coder. I want to create something new for the community, and avoid the problems the SuperCPU and the Flash8 had. Something which not only rich geeks can buy to present it on YouTube. So the most important point for me is, that everything has to be done for free. The main goal is to make this addon as cheap as possible, this is the only way to spread it. Costs are also a reason why there are only C16 and C128 versions.
- The C128 can do everything a C64 can do, but better
- C128DCR is too rare and not fully compatible (VDC 8568, 1571CR)
- The plus/4 is too small and a C16 has to be upgraded anyway
Let's see if there is any interest.
Greets, RetroAndMore.
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Posted By
SukkoPera
on 2024-07-17
03:53:32
| Re: Hardware project for C16 and C128
Maybe you missed the LittleSixteen project? 
V4 is round the corner, I got the *assembled* PCB right last night! This will have a userport, a built-in SID+3rd joystick port, 512kB Hannes-style RAM and much more. I plan to work on it in August, so it will probably see the light in September, unless we find a showstopper issue (which should NOT be the case, basic functionality has already been tested).
Of course you are free to start your own project, but my suggestion would be: please do not do duplicate work, rather join the effort and help make this one even better, it's fully open source. I already have a few things planned for V5, which should be the final release, but of course there can be more  .
While it would be trivial to add (well, apart from finding some space on the board), I don't think a VIA would be particularly useful. Some form of userport is already there and that's what *all* the software using a userport expects. I feel it's even better than the C64 userport in some aspects (19200 bps HW serial communication!). It also has a few drawbacks but those can usually be worked around (missing handshake lines).
I can't say anything for the VDC, except that, as my own experience shows, developers are reluctant to make use of any non-standard HW these days, and without SW support, HW is just useless.
There is also a similar project for the C128, also fully open source, but this one is much more faithful to the original and less open to improvements, aiming mainly at fixing the (lots of) issues with the original board.
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Posted By
gerliczer
on 2024-07-17
07:17:49
| Re: Hardware project for C16 and C128
I read through twice the OP but I couldn't find what the poster wants to build except that it is a hybrid expansion for the C16 and C128. Also, I cannot really understand what "The plus/4 is too small and a C16 has to be upgraded anyway" means. Could you explain your plan in a bit more details, RetroAndMore? Please.
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Posted By
RetroAndMore
on 2024-07-17
07:23:37
| Re: Hardware project for C16 and C128
@SukkoPera:
Yes, and exactly this is the fact I don't understand. Why is everybody replicating boards which are already existing? A replica mainboard of the A500 for 60 USD. These things are existing, why replicating those? Why did not anybody try to make a replica of the C65 board and reverse-engineer the custom chips? That would be useful.
There are so many modifications which could be made. There's a 1581 replica board, but only with a mod to use a PC floppy. Why not making everything more interesting? My plans for a new 1581-compatible 3,5" drive would be:
- Instead of the 8520 a VIA 65C22, these are still prodouced
- Instead of the 6502 a WDC 65C816, these are also still produced
- Both IC's are fully static, available in PLCC format for smaller design and work up to 14 MHz
- If the original WD1772 FDC is used, this chip supports up to four drives
- The 65C816 can access up to 16 MB RAM, allowing 16 1581-sized RAM disks
- These RAM disks can be buffered by a battery
The ROM should be used as close to the 1581, changing only the VIA/CIA routines. A ROM addon should support new formats: 1581, 720K and 1,44 MB FAT12 disks and a new native format with subdirectories and the usual 16-character names. FD-2000 compatibility isn't neccessary because these drives are too rare. It should be possible to create all formats as RAM disks. These are accessed by unit numbers, but a specific floppy/ramdisk can be set as unit 0. A drive like this will be more compatible than any SD-interface for mounting d64-images and if only If only standard components like 74xx and 65xx are used, it is cheaper than a 1541 Ultimate.
The VDC is closer to the TED because both have the problem having no sprites. But correctly programmed, they could do amazing things. TED-FLI looks amazing. VDC-FLI is also great, and in much higher resolution. The main problem of the VDC, the indirect programming, could be solved with my hardware. Amazing would be a genlock, with the VDC transparent on top of the VIC or TED.
You wrote 'Please do not do duplicate work', but integrated a 512kB RAM-expansion by Hannes, and SID-expansions for the plus/4 also were existing. Isn't that duplicating work? And I guess there are different SID cartridges and memory upgrades, which were never regularly used.
My project is a clean project, because it is designed as a pure upgrade project for original hardware. The expansion port stays free, and it only requires a few bytes in memory. I know the problems of the SuperCPU and the Flash8: Great hardware, but you couldn't use it. That's why I planned from the beginning the capability for a new ROM, best containing modern routines from the demoscene. And these routines should be able to be used from BASIC.
I'm wondering that nobody is interested in upgrading all available machines with low cost.
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Posted By
RetroAndMore
on 2024-07-17
07:36:55
| Re: Hardware project for C16 and C128
@gerliczer
My project was originally planned for the C128. There are so many C64 pojects out there, but nothing is for the C128. However, some are noticing the features of the C128. Sonic The Hedgehog, Eye Of the Beholder are making use of the 2 MHz mode. Eye of the Beholder and Attack of the PETSCII Robots are using the VDC for a map display. The 8 -Bit-Guy did not even consider a native C128 version, but it resulted in the best version for an 8 bit computer.
The C16 has a smiliar problem like the C128: The plus/4 was always more common. But in this case, the C16 is better suitable because it has lots of space inside the computer and the outside. The C16 and the C128 are also sharing a similar processor: a 6502 with an 7-bit I/O-port. They are slightly different, but this doesn't matter. So the same hardware can be used on the C128 could be modified to the C16. It also would be a good idea to add a SID and a VIA on the board.
If the new Kernal and BASIC are programmed simultaneously, a higher compatibility could be achieved. For the BASIC, I thought on a completely new version which has not be compatible to other BASIC dialects. It would be more useful to create a converter, which also changes memory addresses and system routines, which are incompatible on every Commodore computer.
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Posted By
gerliczer
on 2024-07-17
09:03:50
| Re: Hardware project for C16 and C128
I still don't quite get what it will do, but good luck.
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Posted By
SukkoPera
on 2024-07-17
08:32:27
| Re: Hardware project for C16 and C128
There are reasons for replicating old hardware. A500+ boards get often eaten by eletrolyte from the battery, sometimes they can be repaired trivially, sometimes it's just easier to move all the known-good components to a new board. My Raemixx500 project only started as a replica, that's the first step to make sure that the design is correct, then we started adding some fixes and upgrades and many more were to come, except that the stupid Amiga community made me furious and I just gave up on it. I might still complete the project one day, but it will only be for my own benefit at that point.
So I moved to the C16/+4 and LittleSixteen V2 started the same way: an almost 1:1 replica to just make sure the design was correct. In V3 we started adding many fixes and upgrades, in V4 we went much bigger. SIDcards and memory expansions already existed, but there was no readily-usable design and they could not be bought anywhere either. So first I resumed those projects individually, tested and refined them, and ultimately I integrated them in L16 V4, which comes with all of that built-in and much more. This is not duplicated work (meaning two people doing the same thing independently rather than collaborating on a single, better project)!
The purpose of these projects was also to DOCUMENT those machines in an open format and with an open license, for preservation for the benefit of posterity.
The C65 was pretty much replicated with the Mega65 project, as far as I'm aware. But it also seems to be suffering from the "nice machine but very little software" disease.
I think I agree with @gerliczer, I don't understand the purpose of your thread. I was assuming you wanted to created a new mainboard but you clearly aren't. You're working on a different project but you don't want to disclose enough information to let understand what it is. Good luck with it anyway!
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Posted By
gerliczer
on 2024-07-17
09:03:28
| Re: Hardware project for C16 and C128
@SukkoPera: suffering from the "nice machine but very little software" disease. And that is exacerbated by their efforts to create a C64 core for their platform, instead of concentrating on improving things on the software side. Or, at least, that was the case last time I checked.
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Posted By
RetroAndMore
on 2024-07-17
11:21:57
| Re: Hardware project for C16 and C128
I didn't offer information yet because I wanted to check first if there is enough interest.
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Posted By
gerliczer
on 2024-07-17
12:44:18
| Re: Hardware project for C16 and C128
Strange strategy. How often do you buy things you know next to nothing about? 
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Posted By
siz
on 2024-07-17
15:01:21
| Re: Hardware project for C16 and C128
I'm with gerliczer on this one. I have no clue what are you talking about.
What exactly (okay, keep it secret, not exactly) do you plan to do? An internal expansion with some new features? Or what? What features do you plan to add? New CPU? Memory? You mentioned SID and VIA (why VIA? why not 6529 to make it compatible with the plus/4 user port?)
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Posted By
javierglez
on 2024-07-19
04:15:23
| Re: Hardware project for C16 and C128
There is nice artwork for VDC out there, but I don't think it is that versatile, at least for games. The equivalent of CGA 160x100x16 takes 24kb instead of 16kb and it's actually the same as 640x200 bitmap mode with 8x2 color cells. There are cool youtube channels from people who have been experimenting with VDC but that's it.
I don't think it's a bad idea to add a VDC to a C16, but it would be niche uses like in the C128, to show a map while the actual game is in the other display, etc.
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