Search found 435 matches

by Pr0f
Tue Jan 28, 2020 7:29 pm
Forum: General QL Chat
Topic: Return of Y2K Bug?
Replies: 3
Views: 106

Re: Return of Y2K Bug?

Well the 32 bit seconds counter is good for 136 years :-)
by Pr0f
Mon Jan 27, 2020 10:38 am
Forum: The Off-Topic Section
Topic: QL vs BBC vs Amstrad 464
Replies: 9
Views: 913

Re: QL vs BBC vs Amstrad 464

Amstrad CPC is significantly slowed down by its video and memory circuits to approx. 3.3 MHz. But is that a 4MHz Z80 being clocked at 3,3MHz to get video timing correct - in which case it is a 3.3MHz Z80 - the speed on the CPU itself is just the maximum rating it can be run at reliably - you can ru...
by Pr0f
Mon Jan 27, 2020 9:53 am
Forum: The Off-Topic Section
Topic: QL vs BBC vs Amstrad 464
Replies: 9
Views: 913

Re: QL vs BBC vs Amstrad 464

Access to screen memory is interleaved with the CPU on the beeb, so the RAM's have to be fast enough to do double work duty, but the processor never has to wait for memory access. It's more than possible to do this with the 68000 as well. I think the Amstrad used seperate memory area for the screen ...
by Pr0f
Sun Jan 26, 2020 5:41 pm
Forum: Software & Programming
Topic: Running SMSQ/E
Replies: 35
Views: 5501

Re: Running SMSQ/E

I sold it to a guy in Godalming who collected old retro machines - I did tell him the hard disk was temperamental but he was just going to put it on display I think/

I'm in Reading - but will happily pay postage. Has it still got that funky 'Q' button on the front?
by Pr0f
Sun Jan 26, 2020 5:12 pm
Forum: QL Emulation
Topic: Minerva 1.98 ROM with QemuLator
Replies: 3
Views: 123

Re: Minerva 1.98 ROM with QemuLator

There is a copy of the Minerva 1.98 ROM image that's size adjusted to work with the Qemulator - http://www.dilwyn.me.uk/qlrom/index.html

That image works for me - version 3.2 of Qemulator.
by Pr0f
Sun Jan 26, 2020 5:04 pm
Forum: Software & Programming
Topic: Running SMSQ/E
Replies: 35
Views: 5501

Re: Running SMSQ/E

I've decided it's time to rehouse my Aurora, it's current case is just far too small. Can any case be used? - I've not stripped the machine down to have a proper look. Hi Rob, if this is the machine I think it is, then it's got the mplane backplane in it (https://qlwiki.qlforum.co.uk/doku.php?id=ql...
by Pr0f
Wed Jan 22, 2020 7:58 am
Forum: Software & Programming
Topic: Reverse Engineering
Replies: 17
Views: 505

Re: Reverse Engineering

It was a fascinaing read - how different the world would be now if IBM had gone with the Motorolla processor's as was their intention originally...
by Pr0f
Tue Jan 21, 2020 10:23 pm
Forum: Software & Programming
Topic: Reverse Engineering
Replies: 17
Views: 505

Re: Reverse Engineering

I remember the first IBM PC manual had a complete listing for the BIOS, so they were not too concerned I had a look at the 2 spectrum rom disassembly books - seems the shadow rom was done with permission - not sure about the Dr Logan book for the main ROM, but there is the usual copyright notices ab...
by Pr0f
Tue Jan 21, 2020 3:33 pm
Forum: Software & Programming
Topic: Reverse Engineering
Replies: 17
Views: 505

Re: Reverse Engineering

I agree - rework or making a copy using the source to make another comercial product would infringe the legality.

But we see a lot of books on disassembly of the spectrum roms for instance - I presume these must have been given legal authority to publish?
by Pr0f
Mon Jan 20, 2020 10:14 am
Forum: General QL Chat
Topic: Designing 3-D cases: vDrive & Q68
Replies: 24
Views: 719

Re: Designing 3-D cases: vDrive & Q68

I think the shielding is to protect external devices from the RF radiation produced by the Q68 - as it's a fast switching digital device

I am sure it will work just fine outside a case, but it is probably not playing nice with the environment ;-)