Sinclair ZX80 / ZX81 / Z88 Forums

I’ve finished my ZX Wespi install too. It’s working like a charm. The ZX81 is a Franck78 clone.

This ZX81 is running on a vLA81 and SRAM wired for 32KB.

Good job! Sorry for the late reaction. Bit going on here.

I’ve made my own composite circuit, based on a transistor, a capacitor, 2 resistors and 2 diodes. Works perfectly on my Timex Sinclair 1000.

That looks indeed like an ULA issue.

Most of the components can be bought from Mouser or Digikey. Reichelt has the 6.5 Mhz resonator brand new. article nr. is SFE 6,5.

Welcome!

So, I bought one of the Issue 3 replica PCB's by Franck78 and I've built it. I can say it has been a satisfying experience. The board is working like a charm :D. Building it was a breeze. I took some pictures while building it. It also has my own design internal 16K modification PCB and composite mo...

I've built the board, unfortunately the ULA is duff and I don't have a working at the moment. However, I took the vLA81 from one of my Zeddy's and it booted up, so the board is working. Awesome board.

Lardo Boffin wrote: ↑Wed Jun 09, 2021 1:02 pm
The dot crawl free board sounds interesting.

I am selling them too, the circuit uses the native video signal from the Spectrum and converts this to s-video. It works with standard s-video leads, 4 pin mini-DIN. The television has to support s-video input. It also works with RetroTink.

Welcome RedHawk, Yes, ‘Kwantum’ … "kwantumsprong" in Netherlands… "Quantensprung" in Deutch… "Saut Quantique" in french… "Salto Quantico" in Italian… May be the Sinclair "Quantum Leap" (QL) in England. this was Sinclair's biggest mistake… build a Motorola 68000 processors, after a Zilogs ! the cust...