Search found 3045 matches

by 1024MAK
Thu Jul 30, 2020 1:37 pm
Forum: Hardware
Topic: Ferranti ULA 5C114E info?
Replies: 9
Views: 476

Re: Ferranti ULA 5C114E info?

Hi. I came across all this Ferranti ULA 5C114E dated 8344.. Would it be safe to test one of these ULA on my CZ spectrum clones? (I don't have any of these last plus models) See here . So going on that, I don’t think you will do any damage. But the 5C ULA chips have less compatible DRAM timing compa...
by 1024MAK
Thu Jul 30, 2020 1:24 pm
Forum: Hardware
Topic: Ferranti ULA 5C114E info?
Replies: 9
Views: 476

Re: Ferranti ULA 5C114E info?

Hmm 16K / 48K models U.K. / Europe 50Hz PAL versions ULA 5C102E - used on issue 1 and some issue 2 boards. Needs the “dead cockroach”. Although not known at the time of the production of the issue 1 boards, the “spider” modification is also needed. ULA 5C112E - used on issue 2 boards. Needs the “spi...
by 1024MAK
Wed Jul 29, 2020 3:42 pm
Forum: Hardware
Topic: CZ1500 ( TS1500 ) composite video mod done
Replies: 3
Views: 286

Re: CZ1500 ( TS1500 ) composite video mod done

Yes 8-)

Well done :D 👍

Mark
by 1024MAK
Mon Jul 27, 2020 4:24 pm
Forum: Software
Topic: Is this a ZX81 recording or not?
Replies: 42
Views: 1503

Re: Is this a ZX81 recording or not?

An advert for Fastload here.

Two Fastload entries in this index

I’m sure you can google as well...

Mark
by 1024MAK
Mon Jul 27, 2020 11:50 am
Forum: Hardware
Topic: No video output from my TS1500
Replies: 15
Views: 539

Re: No video output from my TS1500

Unfortunately the oscilloscope you have linked to is only really useful when working with audio signals. Audio signals are considered to be in the range 50Hz to 20kHz. The signals inside even an inexpensive computer like a ZX81/TS1000 or TS1500 run at 1MHz to 3.5MHz. Frequency is the rate of change ...
by 1024MAK
Mon Jul 27, 2020 11:26 am
Forum: Hardware
Topic: Will using a mono cable in a stereo line-out cause problems with LOAD?
Replies: 3
Views: 154

Re: Will using a mono cable in a stereo line-out cause problems with LOAD?

Will using a mono cable in a stereo line-out cause problems with LOAD? Yes! Mono 3.5mm jack plugs are incompatible with most stereo 3.5mm jack sockets, and stereo 3.5mm jack plugs are incompatible with mono 3.5mm sockets. The socket contacts do not line up with the contacts on the plugs in both cas...
by 1024MAK
Mon Jul 27, 2020 11:19 am
Forum: Hardware
Topic: "mic" and "ear" labels are confusing
Replies: 3
Views: 181

Re: "mic" and "ear" labels are confusing

The Mic is at a ‘volume’ level far below a line out level. As per the manual, it was designed for use with a shoe box sized monochrome cassette recorder, most of which had a ear output and a mic input, both on 3.5mm mono jack sockets. Hence the computers sockets were labelled with the same names so ...
by 1024MAK
Sat Jul 25, 2020 4:00 am
Forum: Hardware
Topic: CZ1500/TS1500 Board and electrolytic miss marking
Replies: 11
Views: 430

Re: CZ1500/TS1500 Board and electrolytic miss marking

I don't konw what does it exactly means but returns 64 ... I am absolutely sure its running at 50Hz as argentinian broadcast is and was PAL-N ... 64 means that bit 6 is set on the “ULAs” input port, which means that the “ULA” is reading the 50/60Hz pin as set for 50Hz. The same as a U.K. ZX81. Henc...
by 1024MAK
Fri Jul 24, 2020 5:55 pm
Forum: Hardware
Topic: CZ1500/TS1500 Board and electrolytic miss marking
Replies: 11
Views: 430

Re: CZ1500/TS1500 Board and electrolytic miss marking

Or this can be used to report back on the state of bit 6 of the “ULAs” input port, bit 6 being the 50/60 Hz input bit. HEX DEC Code Comments === === ============ ================================================ DB 219 IN A,(254) ; input data from port 254 and store in register A FE 254 ; data for ab...
by 1024MAK
Fri Jul 24, 2020 12:20 pm
Forum: Hardware
Topic: CZ1500/TS1500 Board and electrolytic miss marking
Replies: 11
Views: 430

Re: CZ1500/TS1500 Board and electrolytic miss marking

If the machine is working: As the vast majority of the ROM is likely to be exactly the same, I would have thought that a simple BASIC program to PEEK the relevant memory locations and print the values on the screen may be enough. Alternatively a machine code program could be used to copy the ROM in ...