Sinclair ZX80 / ZX81 / Z88 Forums

Is there a way to identify the board version of a ZX Spectrum that doesn't involve having to open it? It has a yellow 48K sticker underneath and serial number: 035-202763 in red by the expansion port. PCB is green and the keyboard membrane cable is dull transparent white. I can also see the heatsink...

I'd like to send and receive data to and from a ZX Spectrum from an external device with a serial port. Can anyone suggest a circuit for adding a serial port to a ZX Spectrum? Would a parallel port work better w.r.t how BASIC reads and sends bytes? It looks like from the ZX side a parallel port with...

Tested and it works beautifully on my Spectrum. I'd still like to test it on my ZX80. Obviously, the hardware works but I'd still like to see how one would do it on a ZX80 with 4K BASIC.

I tried the program on page 175, but only get 16514 printed on the screen. I had to add brackets to the USR command, so perhaps there are other ZX80 4K BASIC specific things I'm missing. The address for the joystick is 1F=31.

Maybe I should just test it on my ZX81 or Spectrum....

I think I found what I need to use:
http://www.myprius.co.za/projects.zip
Easy Add-on Projects for Spectrum, ZX81 and Ace
pages 27, 174

That's fine. Thank you.

How would one alter the KEMPSTON test program for 4K BASIC on the ZX80?

Thank you, everyone. I'm building the interface to be Kempston compatible.

I know, but can you suggest someone who can actually burn me one?

Hi, I'm looking for someone willing to provide me with an 8K BASIC ROM for my ZX80. It doesn't matter if I need to adapt a ROM to be compatible. It's just that I don't have access to a burner.

I can pay via PayPal.