1.) Sinclair invested exactly nothing in decoupling capacatitors, but CMOS rams like them (typically 100 nF tantalum)
2.) There might be a well-known timing problem:
https://www.sinclairzxworld.com/viewtop ... 078#p39078
HTH Siggi
Search found 998 matches
- Tue Feb 20, 2024 3:56 pm
- Forum: Hardware
- Topic: I've borked it
- Replies: 123
- Views: 11178
- Fri Feb 16, 2024 1:24 pm
- Forum: Hardware
- Topic: Hardware check sheet
- Replies: 5
- Views: 596
Re: Hardware check sheet
Pin 35 of ULA is the ocillator input:
There should bei pulses @ 6,5 Mhz
Siggi
There should bei pulses @ 6,5 Mhz
Siggi
- Fri Nov 10, 2023 8:06 pm
- Forum: Sinclair Misc
- Topic: The "Ask Dr Beep anything" thread
- Replies: 17
- Views: 16521
Re: The "Ask Dr Beep anything" thread
What is your most favorite instruction/feature when coding on the Z80 in assembly? On the ZX81 that is the feature that code can be executed during line display, the call to upper memory. In hires I use this mainly to prevent display of a user defined character. In lowres it is used by the system w...
- Thu Nov 09, 2023 6:05 pm
- Forum: Sinclair Misc
- Topic: The "Ask Dr Beep anything" thread
- Replies: 17
- Views: 16521
Re: The "Ask Dr Beep anything" thread
Me too:
ZX81 laptop with Lego docking station:
https://forum.tlienhard.com/phpBB3/down ... hp?id=2612
- Thu Nov 09, 2023 4:29 pm
- Forum: Sinclair Misc
- Topic: The "Ask Dr Beep anything" thread
- Replies: 17
- Views: 16521
- Wed Nov 08, 2023 9:37 am
- Forum: GAMES
- Topic: New ZX81 Games
- Replies: 384
- Views: 713404
Re: New ZX81 Games
Works as expected. :mrgreen: Thanks a lot Siggi PS: Meanwhile I think, that the USB-driver interface (using sysvars SEED and COORDS for return values), which has been designed for usage by BASIC-programs and was later enhanced for usage also by m/c programs, should get a new m/c interface (using reg...
- Tue Nov 07, 2023 2:27 pm
- Forum: GAMES
- Topic: New ZX81 Games
- Replies: 384
- Views: 713404
Re: New ZX81 Games
The rom could be found there: https://www.sinclairzxworld.com/viewtopic.php?p=31962#p31962 But I testet GOL-bugfree in EO, using the ZX81x2 rom. And it worked :o The problems seems to be my USB driver environment, I use to load the program. The USB driver updates some sysvars, to return information ...
- Tue Nov 07, 2023 12:18 pm
- Forum: GAMES
- Topic: New ZX81 Games
- Replies: 384
- Views: 713404
Re: New ZX81 Games
Here it is ():
https://youtu.be/oL-BFEbadu8
https://youtu.be/oL-BFEbadu8
- Tue Nov 07, 2023 8:59 am
- Forum: GAMES
- Topic: New ZX81 Games
- Replies: 384
- Views: 713404
Re: New ZX81 Games
Cubimaze works as expedted and does not crash ... But GOL starts and creates a blanc inverted screen in 2 steps? First leaving corners, Yes the clear corners? NO If so then game loads ok. And then pressing a key (latest version NEWLINE/SPACE) gives the cursor? And THEN setting a colony with Z gives...
- Mon Nov 06, 2023 9:27 pm
- Forum: GAMES
- Topic: New ZX81 Games
- Replies: 384
- Views: 713404
Re: New ZX81 Games
Cubimaze works as expedted and does not crash ...