Search found 695 matches
- Tue May 14, 2024 8:54 am
- Forum: Hardware
- Topic: CPU not starting
- Replies: 15
- Views: 267
Re: CPU not starting
I've got a couple of traces from an issue 3 for comparison. This is from pin 32 of the ULA: https://i.ibb.co/wCcxxD9/NewFile2.png The waveform is the same as yours, which is good because it means your ULA is working. Or at least I think it does. I don't know how to read your 'scope's output. It look...
- Mon May 13, 2024 12:51 pm
- Forum: Emulators
- Topic: Issues with emulators for Linux
- Replies: 21
- Views: 302
- Mon May 13, 2024 12:04 pm
- Forum: Emulators
- Topic: Issues with emulators for Linux
- Replies: 21
- Views: 302
- Mon May 13, 2024 12:01 pm
- Forum: Hardware
- Topic: CPU not starting
- Replies: 15
- Views: 267
Re: CPU not starting
You do need to tell us how you're observing the clock signal and the waveforms around the transistor. If you have an oscilloscope do you know how to capture images from it so you can upload them?
- Mon May 13, 2024 9:14 am
- Forum: Hardware
- Topic: CPU not starting
- Replies: 15
- Views: 267
Re: CPU not starting
Don't connect the ULA directly to the CPU. That's not a good idea. You said "cpu clock on pin 6 is incorrect". What do you mean, "incorrect"? Stuck high? Stuck low? Erratic level? Valid signal but at the wrong speed? Give us some details to work with! Also, what test equipment ar...
- Sun May 12, 2024 6:27 pm
- Forum: ZXDB Discussion
- Topic: Manic Miner/Jet Set Willy no longer available
- Replies: 30
- Views: 1196
Re: Manic Miner/Jet Set Willy no longer available
Given Manic Miner's copyright is disputable (if I'm reading joefish's comment correctly) I humbly suggest MM should be made available again. If they (SP) truly care about it they will need to submit a takedown request with legal proof etc. A takedown request is one option they might pursue. Another...
- Sat May 11, 2024 1:15 pm
- Forum: ZXDB Discussion
- Topic: Manic Miner/Jet Set Willy no longer available
- Replies: 30
- Views: 1196
Re: Manic Miner/Jet Set Willy no longer available
But then there's this, about Manic Miner : <snip!> I read that a few times, trying to understand why the author wasn't just dismissing their own argument. I was rather baffled by it, but I think I eventually understood the point being made. The ultimate point being made is that Software Projects ow...
- Thu May 09, 2024 6:19 pm
- Forum: ZXDB Discussion
- Topic: Manic Miner/Jet Set Willy no longer available
- Replies: 30
- Views: 1196
- Thu May 09, 2024 12:45 pm
- Forum: ZXDB Discussion
- Topic: Manic Miner/Jet Set Willy no longer available
- Replies: 30
- Views: 1196
Re: Manic Miner/Jet Set Willy no longer available
What's sad about that document is it's written by a paralegal. Not a solicitor. It carries no weight whatsoever. Look it up. It wouldn't carry any weight if it had been written by a solicitor either. Until a judge rules on it, it's just people saying what they think, making claims and counterclaims...
- Thu May 09, 2024 9:28 am
- Forum: ZXDB Discussion
- Topic: Manic Miner/Jet Set Willy no longer available
- Replies: 30
- Views: 1196
Re: Manic Miner/Jet Set Willy no longer available
Can't remember (or no one knows?) if it was a bug or deliberate that the tune got progressively worse the more lives you lost (I think one of the delay times for the notes was linked to the number of lives remaining). It was a feature! It's in the disassembly, here . Because I always played with in...
- Wed May 08, 2024 12:18 pm
- Forum: Games/Software
- Topic: Hidden message in Predator
- Replies: 14
- Views: 367
Re: Hidden message in Predator
FWIW I was a student in Southampton and liked it very much. I still live a bit (well, quite a bit) up the road from there.
- Fri May 03, 2024 8:39 am
- Forum: Hardware
- Topic: Pico based Spectrum ROM interface (photoessay)
- Replies: 37
- Views: 1633
- Fri Apr 26, 2024 4:27 pm
- Forum: Hardware
- Topic: DC-DC mod query
- Replies: 6
- Views: 468
Re: DC-DC mod query
To complete the story, in case anyone finds it in a search, I got the DC circuit working. I desoldered the cluster of components, then rejoined them all spread out so I could get access to those underneath. I then printed out the circuit shown here , and went through it point by point, ticking off e...
- Sun Apr 21, 2024 11:26 am
- Forum: Games/Software
- Topic: Jetpac to Microdrive
- Replies: 25
- Views: 1190
Re: Jetpac to Microdrive
There's a remarkably in depth discussion of this exact question from about a year ago here.Redgatemodels wrote: ↑Sun Apr 21, 2024 10:16 am Hi, I guess this is a rookie question, but I am trying to get Jetpac onto microdrive and have failed.
Can it be done?
- Fri Apr 19, 2024 8:16 pm
- Forum: Programming
- Topic: Goodbye,Z80
- Replies: 35
- Views: 2065
- Thu Apr 18, 2024 3:48 pm
- Forum: Hardware
- Topic: DC-DC mod query
- Replies: 6
- Views: 468
Re: DC-DC mod query
I know it's hard to tell, but if TR4 is getting hot, one of the 4116 (or equivalent) "lower" DRAM chips may have failed and is now drawing excessive current. Hence dragging the +12V rail down. I'll have a closer look at your photo later when I'm on a PC. This is the current working versio...
- Thu Apr 18, 2024 3:34 pm
- Forum: Hardware
- Topic: DC-DC mod query
- Replies: 6
- Views: 468
Re: DC-DC mod query
The website/blog you linked to is mine BTW. Yes, I thought so. Thanks for doing that. I wanted to tell you that the schematic has two D15 diodes on it, which has rather puzzled me. I think one of them is actually the new D17 which is one of my green dotted diodes in my image? I was also a bit puzzl...
- Thu Apr 18, 2024 12:17 pm
- Forum: Hardware
- Topic: DC-DC mod query
- Replies: 6
- Views: 468
Re: DC-DC mod query
That's an excellent video, but his final work doesn't look much like the board I have!
I'm still working on it...
I'm still working on it...
- Thu Apr 11, 2024 6:13 pm
- Forum: Hardware
- Topic: DC-DC mod query
- Replies: 6
- Views: 468
DC-DC mod query
I have an issue 3 board which has a faulty 12V supply (reads a wobbly +1.2V). -5V works correctly. I've never tried to fix a DC-DC problem before, so I thought I'd start from first principles. The board has had a DC-DC mod of some sort, so I've had a good look at it and taken notes. Here's an annota...
- Wed Apr 03, 2024 9:42 am
- Forum: Hardware
- Topic: Hardware diagnostics interface (Pico based)
- Replies: 4
- Views: 282
Re: Hardware diagnostics interface (Pico based)
Oh, and during the RAM check that the ROM does, it may be possible to check for some RAM faults that the ROM code does not test for. It's not possible to pick up all RAM faults, because the intention of the ROM routine is to simply work out how much RAM is fitted, NOT if it works correctly. Hence t...
- Wed Apr 03, 2024 9:36 am
- Forum: Hardware
- Topic: Hardware diagnostics interface (Pico based)
- Replies: 4
- Views: 282
Re: Hardware diagnostics interface (Pico based)
The next step would be an instruction trace, Often knowing at what point the Z80 is no longer executing the expected sequence can help identify the problem, or at least narrow it down. If there is no input from the user, the machine should make it to the "copyright" screen with the only v...
- Tue Apr 02, 2024 8:13 pm
- Forum: Hardware
- Topic: Hardware diagnostics interface (Pico based)
- Replies: 4
- Views: 282
Hardware diagnostics interface (Pico based)
Whenever someone pops up asking for help with a broken Spectrum, the initial investigation asked of them is always the same: measure the voltages, tell us what test equipment you have, then do some initial signal checks based on what they can do with the equipment they have to hand. Would it not be ...
- Sat Mar 09, 2024 9:55 am
- Forum: Sinclair Miscellaneous
- Topic: Sinclair QL Design issues
- Replies: 30
- Views: 1243
Re: Sinclair QL Design issues
If the QL had looked like Rick Dickinson's redefinition, it could have had the mechanism from a clockwork mouse inside it and it still would have flown off the shelves.
- Wed Feb 28, 2024 4:45 pm
- Forum: Emulators
- Topic: ZEsarUX 11 Beta
- Replies: 8
- Views: 616
Re: ZEsarUX 11 Beta
I found it complicated and confusing. Sarcastically dismiss the feedback if you like.chernandezba wrote: ↑Wed Feb 28, 2024 3:05 pm 2 Menus. "several screens" is exaggerated
...
Nothing further your honor
- Wed Feb 28, 2024 2:46 pm
- Forum: Emulators
- Topic: ZEsarUX 11 Beta
- Replies: 8
- Views: 616
Re: ZEsarUX 11 Beta
I think you are exaggerating Are you really serious it’s difficult to get to the menu save screen? :oops: I'm not exaggerating. That STL screenshot took me about 10 minutes to make. Getting to the menu isn't difficult. Getting a screenshot of what I wanted proved very difficult. The problem is that...