Sinclair ZX80 / ZX81 / Z88 Forums

English translation (via Google translate): Hello, I am Roel Bakker and I have lived in Leeuwarden for 76 years. I have here, from the past, 4 Kg of handbooks and manuals from ZX Sinclair's past. Give me an address and I'll send it to you. Couldn't get it in my heart to throw it away .... Direct con...

Note: in the following text, the assumption is that the connection is via the ZX81 built in keyboard connections. Three things: The ZX81 keyboard lines that are derived from the A8 to A15 address lines will change state whenever the Z80 puts any address out on the address bus. This includes reading ...

The first thing to say is that as the modulator is completely analogue, it’s unlikely that they will transmit on the exact correct frequency. It’s even less likely that any two will transmit on the same frequency. Hence you have to tune each one in individually. Even if the ULA is faulty, if the mod...

As there are slight differences, maybe the software for the DZXuino does not take account of these differences?

Do the files you want load in an emulator?

Mark

Apart from the filename, they should be the same format. However see also the details in this document

Mark

Lardo Boffin wrote: ↑Sun Jan 03, 2021 10:10 pm The reboot?

Yes!

Mark

ZX Spectrum 128k Toastrack Composite Video Modification to the Modulator Composite video is available on the monitor/RGB socket: Pin 1 = composite video Pin 2 = 0V/GND/ground/screen To replace the RF UHF TV signal from the modulator with a composite video signal, follow these steps: Disconnect the ...

Tomorrow then

As I’m about to watch Magnum P.I.

Mark

You did

Maybe my brain is in slow mode

This is the ROM image that I’m gonna be using

Mark

Any of the cheap Chinese programmers will program (blow) a 27C64, or a 27C128 EPROM. But note that they are unlikely to be able to program the older 2764 or 27128 EPROMs, as these normally require a 21V programming supply. All of these EPROMs are obsolete. OTP 27C256 EPROMs are still available from ...