Search found 3141 matches
- Tue Feb 20, 2024 6:51 pm
- Forum: Website
- Topic: "Sorry but you cannot use search at this time..."
- Replies: 16
- Views: 892
Re: "Sorry but you cannot use search at this time..."
The real problem here, is that many built in functions use the search even though the user or member may not be aware that said function is using the search system. For example, using the quick link 'active topics' (top left drop down menu) uses the search system. The second problem is that some oth...
- Tue Feb 20, 2024 6:33 pm
- Forum: Hardware
- Topic: Making a Scalextric lap counter
- Replies: 20
- Views: 931
Re: Making a Scalextric lap counter
No problem, I like helping people.
You may want to check the video settings, it's currently not working, instead we see a "this video is private" message...
Mark
You may want to check the video settings, it's currently not working, instead we see a "this video is private" message...
Mark
- Tue Feb 20, 2024 10:51 am
- Forum: Hardware
- Topic: Incorrect voltages on Spectrum 3b
- Replies: 35
- Views: 1242
Re: Incorrect voltages on Spectrum 3b
The data lines and the keyboard input lines to the ULA are all pulled high by resistors, so yes, without anything to drive them, they should be around VCC (+5V). Which address lines on the ULA socket did you test? IC3 and IC4 will affect A0 to A6. A14 and A15 should be the same level as on the Z80 s...
- Mon Feb 19, 2024 10:52 pm
- Forum: Hardware
- Topic: Incorrect voltages on Spectrum 3b
- Replies: 35
- Views: 1242
Re: Incorrect voltages on Spectrum 3b
Note, where I quote 5V, this is assuming your VCC / +5V rail is exactly 5V. So if this rail is 4.9V and you get 4.9V where I state 5V, that's fine. With TR3 removed, the ULA and Z80 not fitted: ULA pin 32 = 5V Z80 pin 6 = 5V TR3 base = 5V TR3 collector = 5V TR3 emitter = 0V Current test (between the...
- Mon Feb 19, 2024 6:36 pm
- Forum: Hardware
- Topic: Diagnosing strange 'black screen' video issue
- Replies: 6
- Views: 584
Re: Diagnosing strange 'black screen' video issue
So, from what I can tell, IC1, the ULA and IC14, the LM1889 are okay.
The problem appears to be TR1, R52 or the components or PCB tracks in this part of the circuit.
Mark
The problem appears to be TR1, R52 or the components or PCB tracks in this part of the circuit.
Mark
- Sun Feb 18, 2024 7:14 pm
- Forum: Hardware
- Topic: Diagnosing strange 'black screen' video issue
- Replies: 6
- Views: 584
Re: Diagnosing strange 'black screen' video issue
Hello Snipey and welcome :D Question, was this failure mode present before you started work on this board. Specificity, before you renewed TR1, TR2 and the axial electrolytic capacitors. - in the mean time, the Spectrum remains fully functional, even after the screen is black Can you please expand o...
- Sun Feb 18, 2024 12:02 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
That, but also because of how the ROM code detects how much RAM is present. The ROM is not testing to see how much working RAM there is, it's only testing to see how much RAM there is. This is an important distinction, as the test used assumes that all RAM that is present is fully working. The ROM c...
- Fri Feb 16, 2024 2:45 pm
- Forum: Sinclair Miscellaneous
- Topic: Who do you buy your spare parts from
- Replies: 8
- Views: 716
- Fri Feb 16, 2024 2:42 pm
- Forum: Games/Software
- Topic: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
- Replies: 67
- Views: 2420
Re: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
Oh, and I feel that the small minority with an "80K" RAM upgrade are being left out :cry: Technically it is also possible to have a 32K Speccy (16K rubber key with 16K of expansion RAM). I don't know if anyone ever made expansion packs or fitted suitable DRAM chips internally for this thou...
- Fri Feb 16, 2024 2:38 pm
- Forum: Games/Software
- Topic: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
- Replies: 67
- Views: 2420
Re: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
Yeah but, no, but... Are we speaking about "straight" AY sound chip data, music notation, samples or what? 6K bytes of AY sound chip music data <> as data for samples. Then there is the mass storage system being used. Real tape LOADing on a real ZX Spectrum is rather slower than being LOAD...
- Thu Feb 15, 2024 7:55 pm
- Forum: Website
- Topic: Forum e-mail alerts corrupted?
- Replies: 7
- Views: 582
- Thu Feb 15, 2024 4:30 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
No problem.
It's a lot easier when a DRAM chip fails and produces a binary 1 regardless. When they produce 'random' outputs or bianry zeros, it's a bit more tricky.
Mark
It's a lot easier when a DRAM chip fails and produces a binary 1 regardless. When they produce 'random' outputs or bianry zeros, it's a bit more tricky.
Mark
- Thu Feb 15, 2024 2:57 pm
- Forum: Games/Software
- Topic: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
- Replies: 67
- Views: 2420
Re: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
And artists are often capricious people ;) They may draw some stuff that won't fit you from a coding point of view, as the others said. If you tell them to redraw it, they will get offended and leave. That's it, I'm done with this, I quit, you can finish this topic on your own... :twisted: Mark PS ...
- Wed Feb 14, 2024 11:18 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
strangely the speaker makes no sound when i connect the meter - still reads 39 ohm , the diaphram looks good , moves nicely - does not appear to be held up from vibrating , but no noise - can i put 5 volts into it ? Err, not if you want it to work after. Wire a 220Ω or similar resistor in series to...
- Wed Feb 14, 2024 11:11 pm
- Forum: Games/Software
- Topic: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
- Replies: 67
- Views: 2420
Re: How big should new Speccy games be? 48k? Bigger? Release 2 versions?
So… I was doing some AY music for an upcoming game by @gabriele amore. The actual game is under 48k, so I figured I'd have over 80k for the music, since it can only play on 128k machines. :shock: Oi! My AY card for the rubber key / + Speccy says otherwise... :dance As this is a hobby, I went for op...
- Wed Feb 14, 2024 9:23 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
I will be replacing every cap in the machine Just the electros I presume? Apart from C5 to C8 I mentioned above, the ceramics don't normally cause any problems. took the speaker out , getting 39 ohms across the terminals , from reading , thats good Yes. Does it click if you tap a meter lead as you ...
- Wed Feb 14, 2024 7:55 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
I feel your pain. Buying items from abroad is now a right pain. The U.K. leaving the E.U. has not helped. The real problem is IMHO called VAT. But let's not get into politics. Else we will get into trouble (in this forum, talking politics is almost taboo). The owner of Retroleum is very helpful. But...
- Wed Feb 14, 2024 6:04 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
- Wed Feb 14, 2024 6:02 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
- Wed Feb 14, 2024 5:42 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
Post above edited.
- Wed Feb 14, 2024 5:40 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
So, I'm back :!: :P :lol: For a replacement chip, you either need a TMS4532 - 15NL3 (which are long out of production and nearly as rare as a live Dodo). Or a 4164 DRAM chip, preferable a Texas Instruments (TMS) one. Although various other makes will work as well. If you find any or intend to buy so...
- Wed Feb 14, 2024 3:59 pm
- Forum: Hardware
- Topic: Cant load anything
- Replies: 41
- Views: 1654
Re: Cant load anything
Yes, different DRAM chips are used for 'lower' and 'upper' RAM. 4116 are not suitable to replace a upper DRAM chip.
Be back later, as the site is about to go off-line...
Mark
Be back later, as the site is about to go off-line...
Mark
- Tue Feb 13, 2024 11:16 pm
- Forum: Games/Software
- Topic: C.S.S.C.G.C 2024 is/will be/has open/ing/ed
- Replies: 103
- Views: 5461
Re: C.S.S.C.G.C 2024 is/will be/has open/ing/ed
H2G2 detected
Mark
- Tue Feb 13, 2024 9:36 pm
- Forum: Hardware
- Topic: Making a Scalextric lap counter
- Replies: 20
- Views: 931
Re: Making a Scalextric lap counter
Thanks Mark, I believe using my multimeter I can identify the base so I will just use that as the reference point and hope for the best. Oh no, you don't get off that easy.... https://youtu.be/nCryJU2sh3c?si=olLFSk2XCuEBt19D https://i.postimg.cc/Y4Nmqy8T/IMG-7800.jpg https://i.postimg.cc/c6hMc6RP/I...
- Tue Feb 13, 2024 4:30 pm
- Forum: Hardware
- Topic: Making a Scalextric lap counter
- Replies: 20
- Views: 931
Re: Making a Scalextric lap counter
I'll get a real one out later and take a photo.
Mark
Mark