Search found 5087 matches

by 1024MAK
Mon Mar 18, 2024 6:28 pm
Forum: ZX BASIC
Topic: The PAUSE Bug Explained
Replies: 1
Views: 136

Re: The PAUSE Bug Explained

Thank you 8-)

Mark
by 1024MAK
Sat Mar 16, 2024 7:05 pm
Forum: Hardware
Topic: opus discovery questions
Replies: 4
Views: 167

Re: opus discovery questions

The best source of help with the Opus Discovery is to work your way through the topics over on WoSf . And yes I think you can use a PC 3½ inch disk drive. You will have to change either the internal link, zero ohm link or the cable wiring so that the drive responds to the DS0 signal from the Opus Di...
by 1024MAK
Sat Mar 16, 2024 6:01 pm
Forum: Hardware
Topic: how to verify if a multiface 1 is working ??
Replies: 4
Views: 142

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

Is the /NMI signal getting to the Z80?

Is the multiface paging out the BASIC ROM and enabling it's own EPROM?

Mark
by 1024MAK
Sat Mar 16, 2024 2:40 pm
Forum: Hardware
Topic: Atari joystick without ZXpand+
Replies: 33
Views: 773

Re: Atari joystick without ZXpand+

kmurta wrote: Sat Mar 16, 2024 1:47 pm The Brazilian clones TK82/TK83/TK85 had a joystick input using this scheme. Line A12 is common for keys 6, 7, 8, 0 and line A11 is common for key 5.

The Atari joystick needs to be modified to work in this scheme.
Thank you. That's what I thought.

Mark
by 1024MAK
Sat Mar 16, 2024 10:58 am
Forum: Hardware
Topic: Atari joystick without ZXpand+
Replies: 33
Views: 773

Re: Atari joystick without ZXpand+

Spinnetti wrote: Sat Mar 16, 2024 3:10 am back in 82, I simply cut a hole in the case, put in a joystick port, and hardwired it to the arrow keys... pretty simple....
Ahh, but number 5 key adds complexity. How did you handle "5" being on a separate half row (and hence using a different "common" line to the rest of the keys)?

Mark
by 1024MAK
Fri Mar 15, 2024 10:31 pm
Forum: Software
Topic: ZXpand+ JOYCFG.TXT file
Replies: 7
Views: 278

Re: ZXpand+ JOYCFG.TXT file

There is most definitely a help or example file somewhere, I've seen it. I just can't remember where...

Mark
by 1024MAK
Fri Mar 15, 2024 9:20 pm
Forum: Software
Topic: ZXpand+ JOYCFG.TXT file
Replies: 7
Views: 278

Re: ZXpand+ JOYCFG.TXT file

ZXpand Commander is a file manager/menu/loader program. See this topic... ;-)

Mark
by 1024MAK
Fri Mar 15, 2024 9:16 pm
Forum: Hardware
Topic: ZX Spectrum Issue 6a short
Replies: 12
Views: 272

Re: ZX Spectrum Issue 6a short

The ULA only runs off the +5V. And indeed, the actual supply to the core goes via resistor R34 to pin 13. The ULA has no direct connections to the -5V or +12V supplies. ULA pin 14 just supplies the peripheral interface circuitry. The normal cause of problems with the -5V or +12V supplies, TR4 cookin...
by 1024MAK
Fri Mar 15, 2024 8:43 pm
Forum: Hardware
Topic: Spectrum modded / composite question
Replies: 16
Views: 565

Re: Spectrum modded / composite question

Well, with only seven 4116 DRAM chips fitted, it will do something, but no, it will not run BASIC.

The ULA should however produce a picture. What you get depends on which chip is missing. The effect being different depending on which one it is that is missing.

Mark
by 1024MAK
Fri Mar 15, 2024 1:37 pm
Forum: Hardware
Topic: Atari joystick without ZXpand+
Replies: 33
Views: 773

Re: Atari joystick without ZXpand+

BASIC always uses its own ROM routines to read the keyboard. At the lowest level, this is the Z80 processor using the Z80 machine code IN instruction. Each keyboard half row has its own I/O address. The data returned is one byte, but only five bits are keyboard data. Hence it takes eight IN instruct...