Search found 1157 matches

by mrtinb
Mon Dec 23, 2019 9:19 am
Forum: Sinclair Misc
Topic: A seasonal movie
Replies: 10
Views: 921

Re: A seasonal movie

Crayon21 wrote:
Mon Dec 23, 2019 3:30 am
can't find the download for UDG128
:?:

You need both ZXpand and a UDG128 device like Andy's UDG4ZXpand.
by mrtinb
Sun Dec 22, 2019 12:18 pm
Forum: Hardware
Topic: ZX81 Black screen
Replies: 3
Views: 326

Re: ZX81 Black screen

Try any tv you can find. The older the better. CRTs are preferred. The video signal from the ZX81 is not as precise as newer tvs want. That’s why you don’t get a picture. You have to try other TVs.
by mrtinb
Tue Dec 10, 2019 11:33 am
Forum: Hardware
Topic: ZX80 no "K" prompt
Replies: 12
Views: 1271

Re: ZX80 no "K" prompt

The ZX is not so forgiving. Everything has to be in order for the picture to show, because the picture is purely software :)
by mrtinb
Mon Dec 09, 2019 12:39 pm
Forum: Software
Topic: Hot ZII?
Replies: 26
Views: 3200

Re: Hot ZII?

I have no experience in connecting the a cassette player to pc.

However when I connect a TZXduino output to EAR on a ZX81 or Lambda 8300 to load software, the pulses are 5V. If they are lower the program will not load.
by mrtinb
Mon Dec 09, 2019 11:31 am
Forum: Development
Topic: New year, new projects?
Replies: 12
Views: 2589

Re: New year, new projects?

What I hear you say is: Sometimes EEPROMs can replace GALs if the speed of the EEPROM is sufficient for the circuit. If the speed of the EEPROM is too slow, a CPLD can be used.
by mrtinb
Mon Dec 09, 2019 7:17 am
Forum: Development
Topic: New year, new projects?
Replies: 12
Views: 2589

Re: New year, new projects?

Isn’t an EEPROM a suitable replacement for a GAL?
by mrtinb
Sun Dec 08, 2019 10:15 pm
Forum: Hardware
Topic: Homebrew add-on
Replies: 2
Views: 486

Re: Homebrew add-on

It looks more like a software dongle we know from the PCs printer port. E.g. the software will not work without the dongle attached, hence a pirate copy of the software will not work, as it needs the dongle. P.S. I've asked the administrators to move this post to the ZX81, because it has nothing to ...