Sinclair ZX80 / ZX81 / Z88 Forums

In one of my ZX projects I used these from RS Components: 718-8769 Recept pcb horiz 5 way 2.54mm Trio-Mate and 718-8668 Recept pcb horiz 8 way 2.54mm Trio-Mate small_2012-07-18 22.01.16.jpg The membrane foils fit in there perfectly. Difference with the original ZX connectors is that the pins are not...

Added ZX80 emulation too, selectable by F12 or holding '0' on the original keyboard during powerup.

Let me clarify a bit, on the ZX81 you have PRINT AT, not on the ZX80. All I want to do is preset the next position where the PRINT instruction is going to write to. This must be kept somewhere otherwise how is the Basic to know where to print the next character ? So after a PRINT command it needs to...

Hi, Is it possible to force (POKE) the position of the next character to be printed? I already tried POKE-ing S_POSN but it seems to have no effect. What I would like to do is preset X and Y and then do a PRINT .... I understand I have to fill the screen (partially) with spaces to be able to do rand...

They are read via IN A,31 in machine code (port 31 dec) but often have very basic port decoding.

I had setup a debug function on any unknown IO ports but when I selected Kempston it did not trigger once..
Have to dig deeper I guess or just add some code to emulate the cursor keys with the joystick.

Hi, I have added a ZX80 emulation mode to my NXP81 project and found some 'flicker free' games like Pacman and Krazy Kong which seem to work quite nice. On the opening screen you can select two kind of joystick modes: Sinclair and Kempston but so far I have been unable to find the hardware specifica...

ah, i suspected that you were doing something funky with the display when you mentioned that the display stays updated even in fast :geek: see the problem with hi-res is there are so many different ways to create it, so it would be very difficult to create a catch all software solution for re-creat...

Some pictures from programs running

very nice indeed :-D this is a software emulation then, with the Z80 core been emulated on the arm chip ? does it do hi-res as well as udg ? Regards Andy No hires yet, the Z80 core is emulated in a non cycle perfect way although I am not sure if cycle perfect is really needed for Hires to work, my ...

Some more.. Note this is just a prototype, no commercial intentions so far..