Search found 694 matches

by dfzx
Mon May 13, 2024 12:51 pm
Forum: Emulators
Topic: Issues with emulators for Linux
Replies: 18
Views: 224

Re: Issues with emulators for Linux

Sweevo wrote: Mon May 13, 2024 12:14 pm I am using Linux Mint 21.3 Cinnamon.
Are you using X or Wayland?

It's odd that an application like Fuse is disturbing your system's graphics settings. That really shouldn't be possible.
by dfzx
Mon May 13, 2024 12:04 pm
Forum: Emulators
Topic: Issues with emulators for Linux
Replies: 18
Views: 224

Re: Issues with emulators for Linux

Sweevo wrote: Mon May 13, 2024 11:43 am Can anyone recommend a Spectrum emulator for Linux that does fullscreen, doesn't mess with the desktop resolution and is fully working (i.e. keyboard fully works etc).
What Linux distro (and version) are you using? What version of Fuse have you tried?
by dfzx
Mon May 13, 2024 12:01 pm
Forum: Hardware
Topic: CPU not starting
Replies: 11
Views: 216

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?
by dfzx
Mon May 13, 2024 9:14 am
Forum: Hardware
Topic: CPU not starting
Replies: 11
Views: 216

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...
by dfzx
Sun May 12, 2024 6:27 pm
Forum: ZXDB Discussion
Topic: Manic Miner/Jet Set Willy no longer available
Replies: 30
Views: 1188

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...
by dfzx
Sat May 11, 2024 1:15 pm
Forum: ZXDB Discussion
Topic: Manic Miner/Jet Set Willy no longer available
Replies: 30
Views: 1188

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...
by dfzx
Thu May 09, 2024 6:19 pm
Forum: ZXDB Discussion
Topic: Manic Miner/Jet Set Willy no longer available
Replies: 30
Views: 1188

Re: Manic Miner/Jet Set Willy no longer available

It looks like someone got those trademarks, too.

But the Jet Set Willy one has the wrong sprite. :lol:
by dfzx
Thu May 09, 2024 12:45 pm
Forum: ZXDB Discussion
Topic: Manic Miner/Jet Set Willy no longer available
Replies: 30
Views: 1188

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...
by dfzx
Thu May 09, 2024 9:28 am
Forum: ZXDB Discussion
Topic: Manic Miner/Jet Set Willy no longer available
Replies: 30
Views: 1188

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...
by dfzx
Wed May 08, 2024 12:18 pm
Forum: Games/Software
Topic: Hidden message in Predator
Replies: 14
Views: 365

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.
by dfzx
Fri May 03, 2024 8:39 am
Forum: Hardware
Topic: Pico based Spectrum ROM interface (photoessay)
Replies: 37
Views: 1624

Re: Pico based Spectrum ROM interface (photoessay)

pollito wrote: Thu May 02, 2024 4:41 pm So sorry that our engineer mixed up the order number, there is no issue about the order.
Very odd for JLCPCB to mess up like that, they're normally flawless in my experience. Put it down to an aberration at their end. :)
by dfzx
Fri Apr 26, 2024 4:27 pm
Forum: Hardware
Topic: DC-DC mod query
Replies: 6
Views: 462

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...
by dfzx
Sun Apr 21, 2024 11:26 am
Forum: Games/Software
Topic: Jetpac to Microdrive
Replies: 25
Views: 1184

Re: Jetpac to Microdrive

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?
There's a remarkably in depth discussion of this exact question from about a year ago here.
by dfzx
Fri Apr 19, 2024 8:16 pm
Forum: Programming
Topic: Goodbye,Z80
Replies: 35
Views: 2062

Re: Goodbye,Z80

+3code wrote: Fri Apr 19, 2024 7:17 pm Sad. Somehow, I feel the calendar is running out of pages.
For all the tongue in cheek comments others have posted, sadness is my overwhelming emotion too. :(

Z80s have been part of the computing landscape for about as long as I have.
by dfzx
Thu Apr 18, 2024 3:48 pm
Forum: Hardware
Topic: DC-DC mod query
Replies: 6
Views: 462

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...
by dfzx
Thu Apr 18, 2024 3:34 pm
Forum: Hardware
Topic: DC-DC mod query
Replies: 6
Views: 462

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...
by dfzx
Thu Apr 18, 2024 12:17 pm
Forum: Hardware
Topic: DC-DC mod query
Replies: 6
Views: 462

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...
by dfzx
Thu Apr 11, 2024 6:13 pm
Forum: Hardware
Topic: DC-DC mod query
Replies: 6
Views: 462

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...
by dfzx
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...
by dfzx
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...
by dfzx
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 ...
by dfzx
Sat Mar 09, 2024 9:55 am
Forum: Sinclair Miscellaneous
Topic: Sinclair QL Design issues
Replies: 30
Views: 1238

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.
by dfzx
Wed Feb 28, 2024 4:45 pm
Forum: Emulators
Topic: ZEsarUX 11 Beta
Replies: 8
Views: 612

Re: ZEsarUX 11 Beta

chernandezba wrote: Wed Feb 28, 2024 3:05 pm 2 Menus. "several screens" is exaggerated
...
Nothing further your honor
I found it complicated and confusing. Sarcastically dismiss the feedback if you like.
by dfzx
Wed Feb 28, 2024 2:46 pm
Forum: Emulators
Topic: ZEsarUX 11 Beta
Replies: 8
Views: 612

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...
by dfzx
Wed Feb 28, 2024 2:05 pm
Forum: Hardware
Topic: New open lower RAM module design (photoessay)
Replies: 98
Views: 3728

Re: New open lower RAM module design (photoessay)

However, I think it should be possible to develop the module on a two-layer PCB, and the price difference here is significant. Earlier in the thread you said the price difference at JLCPCB between an order for 2 layer boards and 4 layer boards is about $5. Here in the UK that's less than the cost o...