Search found 5104 matches

by 1024MAK
Fri Mar 29, 2024 12:32 pm
Forum: Hardware
Topic: ZX Spectrum +2a issue with all expansion cards
Replies: 8
Views: 414

Re: ZX Spectrum +2a issue with all expansion cards

With your Kempston joystick interface fitted, test the signals I mentioned in my earlier post to see if any are flatlining or otherwise wrong. So, test these pins on the Z80: Pin Signal 6 Clock 7 D4 8 D3 9 D5 10 D6 12 D2 13 D7 14 D0 15 D1 17 /NMI (should be always high) 18 /HALT (should normally be ...
by 1024MAK
Thu Mar 28, 2024 9:30 pm
Forum: Hardware
Topic: ZX Spectrum +2a issue with all expansion cards
Replies: 8
Views: 414

Re: ZX Spectrum +2a issue with all expansion cards

Not sure it's the ULA. Depending on which version (there were a surprising number not including the various clones), a basic Kempston joystick interface only typically uses the eight data bus lines (D0 to D7), address line A5 (and sometimes A6 and A7), /RD, /IORQ and sometimes /M1. And obviously, +5...
by 1024MAK
Thu Mar 28, 2024 6:19 pm
Forum: GAMES
Topic: how to make something intentionally crappy for the CGC 2024
Replies: 23
Views: 1737

Re: how to make something intentionally crappy for the CGC 2024

Yes, I think you can use those.

Mark
by 1024MAK
Thu Mar 28, 2024 7:48 am
Forum: Welcome Area
Topic: Hiya from voorsk
Replies: 3
Views: 150

Re: Hiya from voorsk

Hello and welcome to our forum Graham! :D :D :D I hope you enjoy this forum :D You are welcome to ask questions! I've not heard of the ULAdigitizer before. It looks like it either copies the video data from the ULA data bus when the ULA reads the video data from the 'lower' RAM, or when the Z80 wri...
by 1024MAK
Sun Mar 24, 2024 5:25 pm
Forum: GAMES
Topic: how to make something intentionally crappy for the CGC 2024
Replies: 23
Views: 1737

Re: how to make something intentionally crappy for the CGC 2024

No, you can use any computer language that was/is available for the Sinclair machine you are using.

Mark
by 1024MAK
Sun Mar 24, 2024 5:23 pm
Forum: SALES
Topic: Best tan ever on a ZX80?
Replies: 1
Views: 184

Re: Best tan ever on a ZX80?

No :o

Mark
by 1024MAK
Sat Mar 23, 2024 8:19 pm
Forum: Hardware
Topic: how to verify if a multiface 1 is working ??
Replies: 11
Views: 537

Re: how to verify if a multiface 1 is working ??

Two things:

The Opus has its own bank switched / paged ROM/RAM system, so there must be a switch or something to prevent clashes between them.

The MF1 looks to be missing a lot of logic chips.

Mark
by 1024MAK
Sat Mar 23, 2024 2:14 pm
Forum: Hardware
Topic: how to verify if a multiface 1 is working ??
Replies: 11
Views: 537

Re: how to verify if a multiface 1 is working ??

I'm guessing, but I would have thought that if the RAM was faulty, you would get different symptons. Is it really permanently soldered to the Speccy :shock: That makes it awkward... Have you checked for solder splashes and short circuits? Also open circuit / bad connection issues? This site has some...
by 1024MAK
Sat Mar 23, 2024 2:10 pm
Forum: Hardware
Topic: What to do with an unusual ZX81?
Replies: 7
Views: 380

Re: What to do with an unusual ZX81?

If it's any help, the ZX Spectrum issue 1 (and some early issue 2) boards that have a different "dead bug" daughter board tend not to be modified (unless they were back in the day). You don't need to snip any wires. Just desolder the two wires going into the modulator from the PCB and secure them so...
by 1024MAK
Sat Mar 23, 2024 11:11 am
Forum: Hardware
Topic: ZX Spectrum 16K keyboard issue - not all keys works
Replies: 2
Views: 154

Re: ZX Spectrum 16K keyboard issue - not all keys works

Hello and welcome :D The first point is that the keyboard is a matrix of eight half rows (five keys in each half row) and five "columns" (eight keys in each column). Hence there are two groups forming the connection to PCB (one of eight and one of five). A hairline fracture in one of the metal layer...