Search found 3129 matches

by 1024MAK
Tue May 07, 2024 4:43 pm
Forum: Website
Topic: Issues changing email address on other site (WoS)
Replies: 16
Views: 278

Re: Issues changing email address on other site (WoS)

I don't know any details on the forum software used by WoS, but on phpBB forums, the powers between moderators and administrators can be very different. Even the powers given to the moderators can vary. A standard moderator can only ban users, not change their details. But the administrators can giv...
by 1024MAK
Tue May 07, 2024 4:36 pm
Forum: Programming
Topic: Bank switching issue
Replies: 38
Views: 1377

Re: Bank switching issue

Well, it all depends on what you are trying to do. Which takes up the most space, executable code or data?

The all RAM mode is only available on the +2A, +2B and +3 models and was presumably intended for CP/M use.

Mark
by 1024MAK
Tue May 07, 2024 4:32 pm
Forum: Website
Topic: Issues changing email address on other site (WoS)
Replies: 16
Views: 278

Re: Issues changing email address on other site (WoS)

I'm happy to add other users that are unable to log in to the WoS forums to my topic on WoS forums.

Please quote your WoS forum user name. And it helps if you PM / DM your old and new email addresses in case Lee or another WoSf admin asks for them.

Mark
by 1024MAK
Tue May 07, 2024 3:19 pm
Forum: Website
Topic: Issues changing email address on other site (WoS)
Replies: 16
Views: 278

Re: Issues changing email address on other site (WoS)

The problem is that Lee does not appear to visit the WoS forums very often now.

I posted a topic about a new user wanting to join back at the beginning of the year, but there was no reply to the topic...

I'll add you to the same topic later once I've found it again.

Mark
by 1024MAK
Thu May 02, 2024 9:02 am
Forum: Website
Topic: Did I mention the search is bad?
Replies: 15
Views: 653

Re: Did I mention the search is bad?

equinox wrote: Wed May 01, 2024 12:53 pm lol, thanks but are you ready to post helpful links every time I do a search?
No :lol:

You can however use a search engine:

Code: Select all

site:https://spectrumcomputing.co.uk/forums/ QL
Mark
by 1024MAK
Wed May 01, 2024 11:34 am
Forum: Website
Topic: Did I mention the search is bad?
Replies: 15
Views: 653

Re: Did I mention the search is bad?

https://www.qlforum.co.uk/

Plus various QL web sites.

Mark
by 1024MAK
Mon Apr 22, 2024 12:59 pm
Forum: Programming
Topic: Goodbye,Z80
Replies: 35
Views: 1971

Re: Goodbye,Z80

Morkin wrote: Mon Apr 22, 2024 11:07 amFTFY ;)
:lol:

Yes, that too :mrgreen:

Mark
by 1024MAK
Sun Apr 21, 2024 3:03 pm
Forum: Programming
Topic: Goodbye,Z80
Replies: 35
Views: 1971

Re: Goodbye,Z80

Morkin wrote: Fri Apr 19, 2024 12:18 pm Well, that's that then.

See you guys on the Amiga forums...
Good luck finding a brand new 68000 MPU...

Mark
by 1024MAK
Sun Apr 21, 2024 3:02 pm
Forum: Programming
Topic: Goodbye,Z80
Replies: 35
Views: 1971

Re: Goodbye,Z80

What does it exactly mean? Brand new Z80 MPUs and the support chips for it that were still available will no longer be manufactured. Yes, there are plenty of used Z80 MPUs on the grey market. But as with many things on the grey market (including trading sites like eBay) what you actually get may no...
by 1024MAK
Sun Apr 21, 2024 2:45 pm
Forum: Hardware
Topic: black plus 2 keyboard fault
Replies: 6
Views: 358

Re: black plus 2 keyboard fault

And if course, the joystick ports are part of the same matrix...

Glad you found the problem :D

Mark
by 1024MAK
Sat Apr 20, 2024 9:36 am
Forum: Website
Topic: "Most users..."
Replies: 7
Views: 1010

Re: "Most users..."

Currently:
In total there are 292 users online :: 12 registered, 0 hidden and 280 guests (based on users active over the past 15 minutes)
Most users ever online was 1411 on Tue 19th Mar 2024 09:18
Mark
by 1024MAK
Thu Apr 18, 2024 2:51 pm
Forum: Hardware
Topic: Timex Sinclair 2040 printer question
Replies: 5
Views: 218

Re: Timex Sinclair 2040 printer question

This printer needs a PSU with a 24V 1A AC output.

Mark
by 1024MAK
Thu Apr 18, 2024 2:46 pm
Forum: Hardware
Topic: black plus 2 keyboard fault
Replies: 6
Views: 358

Re: black plus 2 keyboard fault

Okay, that's weird... The keyboard matrix is pure hardware and what program is running shouldn't make any difference to the hardware. Having said that, BASIC and some games will ignore a key if two of the normal keys are detected to be pressed simultaneously. That may explain why the symptoms are di...
by 1024MAK
Thu Apr 18, 2024 2:26 pm
Forum: Hardware
Topic: DC-DC mod query
Replies: 6
Views: 389

Re: DC-DC mod query

So, over the lifetime of the Spectrum, there were various changes to the circuitry including that of the DC-DC converter section. The website/blog you linked to is mine BTW. On your board, you may have either an earlier version or it has just been implemented differently. The service technicians tha...
by 1024MAK
Tue Apr 16, 2024 2:16 pm
Forum: Hardware
Topic: black plus 2 keyboard fault
Replies: 6
Views: 358

Re: black plus 2 keyboard fault

It may be that the problems with the keyboard existed before you opened the case. Were you able to test it before opening it? The keyboard uses a membrane, which itself is wired as a matrix of "switches". The "normal" keys (those that are the same as in a rubber key model) use a ...
by 1024MAK
Mon Apr 15, 2024 9:11 am
Forum: Hardware
Topic: +2B with a non responsive keyboard
Replies: 37
Views: 5641

Re: +2B with a non responsive keyboard

With faults, I much prefer members to start a new topic. This saves confusion. However, I'm not an admin or moderator here.

Mark
by 1024MAK
Mon Apr 08, 2024 5:26 pm
Forum: Programming
Topic: Bank switching issue
Replies: 38
Views: 1377

Re: Bank switching issue

So, just the few instructions needed to switch banks then I guess? I was expecting a bigger speed penalty to bank switching. The latch chip that stores the extra address bits for the memory is just as quick as the Z80. The limiting factors are what you have to do in your software routine and the OU...
by 1024MAK
Sun Apr 07, 2024 10:40 am
Forum: Hardware
Topic: Question about 48K composite mod
Replies: 5
Views: 315

Re: Question about 48K composite mod

I assume you were using an original Sinclair power supply unit (model UK1400 9V 1.4A). This is not a universal mains voltage type, as it requires a nominal 240V AC 50Hz mains input voltage. It will not produce enough output voltage if connected to a 110V – 120V 60Hz mains supply. The good news is th...
by 1024MAK
Sat Apr 06, 2024 1:53 pm
Forum: Hardware
Topic: Question about 48K composite mod
Replies: 5
Views: 315

Re: Question about 48K composite mod

Yes, it has definitely been modified. The (phono) output connector on the modulator (what was the UHF TV output) will now output a composite video signal. I can't tell which version (there are more than four...) of the composite video modification has been done. If you want to know, you need to care...
by 1024MAK
Tue Apr 02, 2024 9:49 pm
Forum: Hardware
Topic: Hardware diagnostics interface (Pico based)
Replies: 4
Views: 260

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 th...
by 1024MAK
Tue Apr 02, 2024 9:45 pm
Forum: Hardware
Topic: Hardware diagnostics interface (Pico based)
Replies: 4
Views: 260

Re: Hardware diagnostics interface (Pico based)

Nice 8-) 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 th...
by 1024MAK
Tue Apr 02, 2024 5:33 pm
Forum: Programming
Topic: Bank switching issue
Replies: 38
Views: 1377

Re: Bank switching issue

It's called bank switching or paging, but at the hardware level, the value on the data bus from the OUT is stored in a latch (register). Then some of the bits are used as extra address lines to the memory (ROM and RAM). The effect of this is that as described above, the Z80 can only see a "wind...
by 1024MAK
Sun Mar 31, 2024 8:49 pm
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 609

Re: Zilog's Z80 opcode choice

CP/M became a big thing and certainly helped make the Z80 successful. I don't know if during the design of the Z80 CP/M was considered. But it may have been. As far as I can recall, the 6502 did not have a direct equivalent to CP/M back then. There was FLEX for the 6800, and then later on a version ...
by 1024MAK
Sun Mar 31, 2024 4:37 pm
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 609

Re: Zilog's Z80 opcode choice

To be fair, the 6809 came along a lot later, and because it was late to the party, and hence not established (so not as cheap) only made it into a small number of computer models.

Yes, it was a good and powerful microprocessor.

Mark
by 1024MAK
Sun Mar 31, 2024 7:34 am
Forum: Programming
Topic: Zilog's Z80 opcode choice
Replies: 20
Views: 609

Re: Zilog's Z80 opcode choice

This is probably more of a general Z80 question rather than applying to the Spectrum specifically, but do you think when Zilog designed and implemented the Z80's instructions and assigned them to either 1 or more byte opcodes that they always made the right choice? I'm not really talking about hypo...