Search found 1724 matches
The ULA is pretty much the only IC that you’ll need to worry about. If it’s a later board revision (Issue 5 and 6), then another custom IC is the ZX8401. The LM1889 and the lower RAM ICs are difficult—but not impossible—to come by nowadays, even though they used to be off-the-shelf parts. I suggest ...
- Sun Sep 20, 2020 10:07 pm
- Forum: Programming
- Topic: More Multicolour - Trailblazer Roadway
- Replies: 12
- Views: 434
Could the effect be extended into the border ? The areas seem large enough for that. Since you can’t use the inverted INK/PAPER trick in the border area, the minimum step for a color change in the border area is eight “pixels” (four T states). That, and the inability of the ULA to render bright col...
there is a 20" Sony Bravia local to me on gumtree for £25. If the seller agrees I could bring the +2 round, hook it up and if it works all good. That’s certainly an option. It’s ultimately your choice, but if you’re thinking of purchasing a dedicated TV set for you Speccys, may I suggest you get a ...
- Fri Sep 18, 2020 11:17 am
- Forum: Hardware
- Topic: Issue 2 TR4 keeps blowing and DRAM is tested OK
- Replies: 13
- Views: 345
The ULA is supplied only by the +5V (from the 7805 voltage regulator), so it is definitely not the cause of your problems. It is designed to run hot. Internally the logic runs on a 0.85V to 0.95V supply so there are on-chip series voltage regulators to drop the supply voltage (pin 13 which should b...
- Thu Sep 17, 2020 11:20 pm
- Forum: Sinclair Miscellaneous
- Topic: TZX format specification
- Replies: 5
- Views: 233
The only other link I've found so far is this one , but I don't know who runs that site. That would be Günter Woigk, the author of zasm and zxsp . A brilliant guy. The TZX spec page is a copy of the one Ralf linked to (oh, and MrClump, too). I’ve never seen another version, so I’ve always taken it ...
- Thu Sep 17, 2020 11:10 pm
- Forum: Hardware
- Topic: Grey +2 RGB SCART help wanted
- Replies: 9
- Views: 220
I heard some +2s have incorrectly placed transistors. Which transistors are affected? And what problems would it cause? It’s the three 2N3904s: TR4, TR5, and TR7. TR7 and TR5, even if mounted incorrectly, will generally cause no trouble with the video signal. TR4 is part of the circuitry that forms...