Sinclair ZX80 / ZX81 / Z88 Forums

A white screen means the the ULA is working.. and that's very good news for a 1500 as is the only one part you can't replace this days!!!.. Z80 from a TS1000 should be the same. If ICs were ruled out. Check all data and address lines. Pin by pin . Have in mind that some lines have resistors in them ...

As far as I know TS1000 ULA all are the newer kind with backporch. They were released on 1982.. but I may miss something...

Thank you Mark..
As clear as water.. !

I'll just add WRX High Res compatibility to the combo..
And perhaps a joystick port..

McKlaud wrote: ↑Tue Mar 09, 2021 6:13 pm Oh, I am so sorry, I didn't know. I can see CZ1500 works well. So, have a lot of fun with the machine.

Don't have to be sorry
Yes it's very Fun indeed.. !!!

Hi, Your CZ1500 is the same like any late TS1500. The main difference is that there is a blob of solder on the 50Hz SELECT jumper. Looking at your photos I can say that the RF modulator is NTSC type like in mine America TS1500. You can easily modify this machine to the composite video output. Such ...

Bola_dor, Can you do reverse engineering on the CZ1500 and draw a schematic? Then post it here. Thanks, DesSony Oh. I missed this out :( I am sorry about answering so late.. CZ1500 were made of completely original parts from Timex Portugal. These were late board designs with the ram layout and the ...

Thanks.. That’s good to know

A white screen with no cursor usually means ULA is working.. at least the video sync is being created. Before concluding all the ICs are wrong please check them on the working board.. At least the Z80 was not working. But check it on the other board anyway. You may have something wrong with the boar...

XavSnap wrote: ↑Sat Dec 05, 2020 8:02 pm

Code: Select all

1 FOR A=0 TO 15
2 PRINT AT 20,10;"HELLO WORLD"
3 SCROLL
4 SCROLL
5 NEXT A
6 COPY

COPY can't be use on a compressed D_file !
And SCROLL can't be use with a COPY command.

Wow. Never tried it.. what would be the behavior?