Search found 212 matches
- Sat Oct 05, 2013 12:24 am
- Forum: GAMES
- Topic: New game finally available after 30 years in development!
- Replies: 2
- Views: 2703
New game finally available after 30 years in development!
Deflection.jpg Well, sort of. Here's the story: When I bought my Sinclair kit in 1982, a friend of mine who was studying computer science, (and just happens to be a friggin' genius), came down with the unusual Adult Onset Juvenile Diabetes. To make his hospital stay more interesting, I smuggled him...
- Thu Aug 29, 2013 11:57 pm
- Forum: WANTED
- Topic: Timex Sinclair 1000 ULA & Timex Sinclair 2020 tape recorder
- Replies: 9
- Views: 12965
Re: Timex Sinclair 1000 ULA & Timex Sinclair 2020 tape recor
Hi Paulo,
If you haven't found a donor unit already, there is a discussion here: viewtopic.php?f=7&t=1180 about replacement ULA's that have become available from new old stock.
See eBay item: 261273794335
Ian
If you haven't found a donor unit already, there is a discussion here: viewtopic.php?f=7&t=1180 about replacement ULA's that have become available from new old stock.
See eBay item: 261273794335
Ian
- Mon Aug 19, 2013 9:13 pm
- Forum: Hardware
- Topic: Remanufactured ULAs?
- Replies: 57
- Views: 25067
Re: Remanufactured ULAs?
What's the most interesting ULA failure you've ever seen? I have one that overwrites the first character of the active line across all unwritten positions of the last line of the general display. For example, for J = 1 to 5 scroll print J next J ... would produce a 1 with the rest of the line fille...
- Sun Jul 14, 2013 7:26 am
- Forum: Lambda 8300/ Power 3000 Lounge
- Topic: Lambda 8300
- Replies: 20
- Views: 31702
Re: Lambda 8300
There are more knowledgeable folks about than I, but I'll tell you what I found with my relatively recently acquired example. What is the DC voltage & amperage in? I've seen it listed between 10.8V 500ma and 12V Mine came with a monster 12V 1.8A combination transformer and cosmic ray deflector. That...
- Wed May 29, 2013 5:15 am
- Forum: Hardware
- Topic: 16K RAM Pack Schematic / Chip Layout
- Replies: 71
- Views: 47814
Re: 16K RAM Pack Schematic / Chip Layout
Thank-you for the links. Interesting material. I guess there's quite the science to diagnosing the spookier classes of errors. The tiny program I have already is, (I see now), a simple "march algorithm", intended to spot "stuck at" faults. It is good enough to figure out if a 4116 has gone to chip h...
- Wed May 29, 2013 12:49 am
- Forum: Hardware
- Topic: 16K RAM Pack Schematic / Chip Layout
- Replies: 71
- Views: 47814
Re: 16K RAM Pack Schematic / Chip Layout
Success!
My jury-rigging had caught up to me. I had a cold solder joint at the diode.
The board is now merrily testing 16K. Write 0, read back 0, write 255, read back 255, working so far. (This is with a good pack.) So the circuit works, and you're a genius (again) PokeMon.
My jury-rigging had caught up to me. I had a cold solder joint at the diode.
The board is now merrily testing 16K. Write 0, read back 0, write 255, read back 255, working so far. (This is with a good pack.) So the circuit works, and you're a genius (again) PokeMon.
- Tue May 28, 2013 11:41 pm
- Forum: Hardware
- Topic: 16K RAM Pack Schematic / Chip Layout
- Replies: 71
- Views: 47814
Re: 16K RAM Pack Schematic / Chip Layout
So when you try to read (with PEEK) from S0 and $8000 - do you get same values ? And try $0001 and $8001 - will be the same ? Yes, what I'm seeing starting the loop at $8000, is an echo of what is at $0000. After a POKE, the value remains unchanged. I tried playing with the diode again but it doesn...
- Tue May 28, 2013 9:52 pm
- Forum: Hardware
- Topic: 16K RAM Pack Schematic / Chip Layout
- Replies: 71
- Views: 47814
Re: 16K RAM Pack Schematic / Chip Layout
* A15 from main board D'oh! That's me, my bad. I got so hung up on soldering pins 5,6, 8, & 9 together I forgot to connect them to A15, then when I checked I was looking for vertical lines. Okay, now it boots. The RAM pack is not seen yet however. I have been using a working RAM pack for initial ex...
- Tue May 28, 2013 7:01 pm
- Forum: Hardware
- Topic: 16K RAM Pack Schematic / Chip Layout
- Replies: 71
- Views: 47814
Re: 16K RAM Pack Schematic / Chip Layout
Still "no go". Yes, I remembered to power the chip. I now have the 4148 in circuit. (Tried 2 different diodes, and tried reversed polarity just in case--all "no go".) So I did "the experiment" you first thought of PokeMon. WIth A14 of the RAM pack taken to ground instead of the 74HTC02 gate output, ...
- Tue May 28, 2013 6:51 am
- Forum: Hardware
- Topic: 16K RAM Pack Schematic / Chip Layout
- Replies: 71
- Views: 47814
Re: 16K RAM Pack Schematic / Chip Layout
My 74HCT02 chip arrived today, so I wired the circuit up, with a known good ZX81 and RAM pack. It won't boot for me. Admittedly, the way I've implemented it is far from elegant, but I've checked the connections and they seem to be correct. The RAMCS and A14 connections have been "broken" by using ce...