There was a time in the early 1980s when it was common to see home made keyboards for 8-bit machines that came with membrane or rubber keyboards. Though we’ve seen any numbers of home made modern ‘boards, it’s been decades since we saw one for an 8-bit micro. Until today, that is, when we saw [Vlad]’s Sinclair Spectrum. It’s a Spectrum with all that Sinclair glue logic that was in the ULA replaced in software by an RP2050, and that keyboard with the Spectrum decals.
The machine is a charming mixture of new and old, with a traditional cassette port alongside VGA, gameport joystick, and Sinclair joystick. The aim is to also have HDMI, though it’s not yet implemented. Sadly there is no Spectrum edge connector for period peripherals though. He admits it’s not cycle accurate to the original, but given that it runs all the games he’s given it this seems not to matter. Meanwhile that keyboard which caught our eye is a true period piece, sitting as it does on a piece of phenolic stripboard, and those decals are the perfect finishing touch.
The Spectrum receives quite a bit of love today, and if this one takes too many modern liberties for your liking, you can still make one using proper logic.
Back in the early 80’s Jameco carried quite a few keyboards. Several of my friends updated their ZX-81 using them. I planed to myself but just bit the bullet and bought a C64.
Jameco, now there’s one I haven’t heard or used in a while.
I think I’ve still got one of their paper catalogues somewhere, they had quite a selection, it’s a shame they haven’t made it here yet. There’s not a whole lot in the way of places that sell components around here. There’s something to be said for being able to walk into a physical shop and handle parts, no waiting for a delivery. Clicking a toggle switch to see if it feels right. etc.
VGA to HDMI adapters are really cheap.
Hdmi to VGA are cheap. VGA to HDMI adapters do not exist.
Depends on how generous you want to be with the word adapter. There are Retrotink, OSSC, and PixelFX devices which can convert VGA to HDMI. But these are more upscalers than adapters and certainly not cheap like the HDMI to VGA adapters can be.
Also keep in mind that lots of cheap HDMI to VGA adapters are bad at what they do. The bad ones crush black levels so everything darker than a certain threshold just becomes solid black. Maybe not a concern for a ZX Spectrum clone though, anything not solid black coming out of a Spectrum is probably bright enough to avoid getting crushed.
Hmm, that can be a good idea anyway. In this project I don’t need to truly convert analog VGA to HDMI because I have “digital” VGA signals out of rp2350b. So I only need to translate them to TMDS which is much much easier.
All I want is a Pi400 in 48K colours
I spent countless hours of my youth trying to program my own games in assembler code. Got one thing published in a hobby magazine. My favorite game was Fred for which I had of course a survival poke.
I used to make ZX keyboards from scratch back in 91s
what is a RP2050 ?
I’m glad the cassette interface was retained.
There was amateur radio software for SSTV and RTTY
that could use it as a primitive D/A and A/D converter for audio signals.
This gave the ZX Spectrum real practical use and made it more than just a toy computer.
The software’s author was G1FTU, I believe.
This is very cool. Does anyone have a source for these key switches that fit regular phenolic perfboard? I’ve never been able to find any with footprint that fits without having to drill a hole in the middle and bodge it in.