collapseos
collapseos copied to clipboard
hsoft
ZX Spectrum Support
Although its success was limited in the US the ZX spectrum was fairly popular in the UK, would it be possible to add it as one of the systems to get this running on
I don't have vintage z80 computers myself, so I'm in uncertainty here. I have the intuition that if we have recipes for one "standard vintage z80 computer", that this recipe will be very similar to all other vintage models. That's why there only the TRS-80 on the roadmap.
That being said, I don't have a TRS-80 either. So if someone makes recipes for a ZX Spectrum, it would be awesome and that will become the "canonical vintage recipe". Then, we'll see if recipes for other vintage computers are similar or not.
FWIW I still have the manual for the Nascom II. I can't access it because it's in storage (with the hardware), but expect it is available online in some retro forum etc. It contains full schematics, PCB layouts, and I think maybe hex dumps etc. and all components were off the shelf, so relatively easy to rework and adapt (ICs were all mounted in sockets too).
The Spectrum may be hamstrung by early use of ASICs which Sinclair favoured, along with a more closed commercial, mass production manufacture. I don't know about the TRS80, but was mass produced so may be a bit tricky too. The plus side is that lots were built and both compact and easy to hang onto, so there will be many more still lying around. Both were pretty robust, compact and nicely packaged, so big pluses for that too.
I never owned a Spectrum but followed it at the time because it caused a lot of interest and excitement in the UK. It was very nice to use for its size, simple but iconic product design, and was well loved, so it would be great if it can have a new lease of life.
My two cents.
Here you have all the Speccy models schematics. Also, the ULA has been fully reverse enginereed, you can get the book "The ZX Spectrum ULA", it contains all the equivalent schematics of the ULA so it can be reproduced with basic gates. There's the Harlequin (docs are in spanish, if you need translation ask for it :) ) which is a Spectrum clone with off-the-shelf components instead of an ULA.
If you need testing I have a good bunch of them and I will be glad to test it :) Finally, there are a ton of emulators running 1:1 to the real hardware like FUSE or Retro Virtual Machine
I have an Amstrad CPC 464 which runs a z80, which I'd be happy to use for testing too, although I doubt I have the ability to do so currently.
This is just another "me too" comment.
I would like support for ZX Spectrum too (either 48k or 128k versions).
Not only does the ZX Spectrum have a Z80, it is also extremely scavenge-friendly. It can be (and is regularly) built using only standard logic circuits, surprisingly cheaply and in more than one known way (it has been frantically cloned in the Eastern block before the Iron curtain went down; a situation similar in some ways to post-Collapse). Its minimal configuration is 16k ROM 8k RAM (though no 8k version has ever been produced and is of very limited practical use, given that only 512 bytes remain for BASIC programs (it can be extended to about 680 bytes), with the 6.75 kilobyte graphical video frame buffer eating most of that RAM. To be useful, it needs 16 kilobytes of RAM, which is the minimal configuration with which it was ever produced.
Also worth considering are Sinclair ZX80 (4 kilobyte ROM, 1 kilobyte RAM) and Sinclair ZX81 (8 kilobyte ROM, 1 kilobyte RAM), which are essentially the same machine with the ZX81 replacing a handful of discrete logic ICs with one ASIC; so in practice, you'd be building ZX80's with minimal upgrades. Either ROM can function in both machines. The main difference is that the 8k ROM has a stack-based floating-point VM and a BASIC interpreter based on it, whereas the 4k ROM has an integer-only BASIC interpreter.
These earlier machines have character-based displays, the ZX Spectrum has only a graphics framebuffer into which it draws characters pixel-by-pixel (okay, 8 pixels by 8 pixels).
There are plenty on eBay, you can get those for 30 or 40€. I see you're from Canada so may be easier to get a Timex Sinclair from USA, they're more or less the same, it's the NTSC version of the Sinclair machines (ZX81 / ZX Spectrum). Also, there are other options, you can get a clone like the Minstrel (and that's a plus as it's made completelly of regular 74xx IC's, no custom ULA's) you can buy it premounted, on kit, or just the PCB and assemble it by yourself.
Also, other option is to test it on an emulator, you can use Zesaurux, FuSE, RVM, etc.
#105 is merged, which means that ZX Spectrum support is in, but in the z80asm branch. Conversion to Forth is still needed.