Sinclair ZX80 / ZX81 / Z88 Forums

Hello, I think I'm ready to produce my new cart in batch, if there is enough interest... What is it, what can it do? - ZX81 expansion cart - 32kB RAM with WRX high res support - CURSOR joystick emulation (with standard atari joy) - ~240 games/apps to load (no save), for complete list, check attachme...

Mark,
PM sent.

The batch of rev3 cards (20pcs) are ready. They work as expected: voltage regulator is cool (GAL chips runs warm/hot, but I think that is OK), green and yellow LEDs are just fine in luminance (reads flash chip, reads SD cards, expands ZX81 with 32kB RAM). What doesn't look good on the data sheet is ...

I'm measuring quite a contradicting currents... So, originally I was using 1117-5.0 for creating the 5V out of the 9V rail. I measured the 9V current and it was 220mA. I didn't even check the output current, I took granted that it is the same. Then I measured with an XC1314G based buck converted. It...

Although it’s quite pricey, one of the RECOM DC/DC converters, or the Traco Power equivalent, or even the MuRata versions. Mark well, ok. I thought about this one: https://www.hestore.hu/prod_10042763.html (hx1314g) and that is around 1.5EUR. But unfortunately it builds up the voltage too slow, pro...

You can see the cart in work here: https://youtu.be/62i6qcQ1nV8 (and my messy desk also, sorry for that). I have some issues to solve, still. The switching PSU board doesn't seem a good choice right now. I'm getting familiarize myself with the original idea, the 1117-5.0 voltage regulator, but that ...

Lardo Boffin wrote: ↑Sat Sep 23, 2023 5:13 pm Will you post to the UK? Certainly looks interesting!

Hope so, we'll see when we get there... (no rev3 boards made yet)

Paul wrote: ↑Sat Sep 23, 2023 2:46 pm From which country will you be sending?

Hungary / Europe

The one with having the XC1314G controller IC. Small, efficient enough. I need to try out, here lies one on my desk, just have time to it.

Once I have a final, rev3 board, I plan to sell for 35eur + pp. I don't know how to advertise this. I hope there will be some interest.

So, here it is, the rev2 board. It has 32kB RAM. It has a reset button. It has a 56780 or Kempston (selectable by a jumper) joy port. It has a flash IC (supported 2-16MB) with custom selectable content. It has a microSD slot from which you can load programs. Flash and SD can load .p files. WRX Hi-Re...