Search found 1078 matches

by dominicbeesley
Fri Aug 07, 2020 10:39 am
Forum: acorn & bbc micro user group (abug) events
Topic: Weeknight 'Virtual' Dev session #0, Thursday 6th August 2020, 7pm - 10pm
Replies: 36
Views: 804

Re: Weeknight 'Virtual' Dev session #0, Thursday 6th August 2020, 7pm - 10pm

Interesting evening. Great to see the breadth of stuff being done on the Beeb.
by dominicbeesley
Wed Aug 05, 2020 7:00 pm
Forum: acorn & bbc micro user group (abug) events
Topic: Weeknight 'Virtual' Dev session #0, Thursday 6th August 2020, 7pm - 10pm
Replies: 36
Views: 804

Re: Weeknight 'Virtual' Dev session #0, Thursday 6th August 2020, 7pm - 10pm

Hi,

Dave's just pointed me at this. I'll try and drop in tomorrow evening. I've not got much to show but am interested in what everyone's doing

D
by dominicbeesley
Sat Aug 01, 2020 11:02 pm
Forum: 8-bit acorn emulators
Topic: BeebEm Alpha Fork with SID and PAULA sound
Replies: 20
Views: 1943

Re: BeebEm Alpha Fork with SID and PAULA sound

Sorry yes, the frequency us 50MHz*9/127 (I cribbed the code in B-em from my BeebEm Blitter board code and forgot to change it!) I'm not sure what version you were using but there was a fairly major bug had crept in somewhere that was breaking all sorts of things subtly and not so subtly (a simple ca...
by dominicbeesley
Sat Aug 01, 2020 12:03 pm
Forum: 8-bit acorn emulators
Topic: BeebEm Alpha Fork with SID and PAULA sound
Replies: 20
Views: 1943

Re: BeebEm Alpha Fork with SID and PAULA sound

Hi Nigel, Is there anything to download for this yet? I'm going to try and give MAME another try soon. I will hopefully get some time this weekend, I was supposed to be going away for the weekend but we've been locked down again. That frequency is indeed 50Mhz divided down to a "near enough" figure ...
by dominicbeesley
Wed Jul 29, 2020 10:29 am
Forum: development tools
Topic: 8bitworskhop's Dithertron - mode 2 screen generation on your browser
Replies: 1
Views: 184

Re: 8bitworskhop's Dithertron - mode 2 screen generation on your browser

Nice idea for testing out stuff. Kind of jsfiddle for the c64. Do you know what c compiler it uses?
by dominicbeesley
Sat Jul 25, 2020 4:11 pm
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

Re: RiscPC cmos/clock

Well, I got a new clock crystal and that has fixed the cmos and clock both seem to be working - unfortunately it looks like the SCSI disc is dead I get a good sounding spin-up then a couple of clunks and a filecore error when I try to start up that drive. I'll post another question about investigati...
by dominicbeesley
Fri Jul 24, 2020 12:46 am
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

Re: RiscPC cmos/clock

I'll give it a try thanks but I've scoped the crystal with a high impedance scope probe and it is dead so i suspect i need to replace the crystal or the cmos cop chip.

Thanks for the pointer

D
by dominicbeesley
Thu Jul 23, 2020 9:42 am
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

Re: RiscPC cmos/clock

I got a bit further with this. The cap was charging up ok but the trace around the 47r resistor was rotted away. Bodgewired thay and now have cmos settings working but unfortunately the clock still wont start. I've cleaned up and checked voltages and continuity round the chip and crystal but it won'...
by dominicbeesley
Sat Jul 18, 2020 11:53 am
Forum: past all-day virtual ABugs
Topic: All-day 'Virtual' Acorn session #6, Saturday 1st August 2020, 9am - 11pm [NOW FULL!]
Replies: 105
Views: 3601

Re: All-day 'Virtual' Acorn session #6, Saturday 1st August 2020, 9am - 11pm

Yes please!

Ps thanks for the reminder thread Dave. I nearly missed this one too!

D
by dominicbeesley
Fri Jul 17, 2020 11:49 am
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

Re: RiscPC cmos/clock

I'll see how it goes but if the cap is only charged to 1.2V (anything above that should be enough for the RTC) 360 ohms should give 10mA so the leakage will be negligible and the ESR should be of the order of half an ohm so also negligible. I'd attach a scope and monitor it but I have no appetite fo...
by dominicbeesley
Fri Jul 17, 2020 11:04 am
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

Re: RiscPC cmos/clock

Yes I'm going to reduce them though it should only take an hour to charge up to 63%....I'll try just leaving it on first

Thanks

D
by dominicbeesley
Thu Jul 16, 2020 1:34 pm
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

Re: RiscPC cmos/clock

Thankyou - that is perfect. It looks to be similar to what I was expecting. I'll have a poke with the scope and see if it looks dead - possibly crud on the crystal? I like supercaps for ease of use - not sure how long a 1F cap will last maybe it just needs leaving on for a while to charge up, if it'...
by dominicbeesley
Thu Jul 16, 2020 11:14 am
Forum: 32-bit acorn hardware
Topic: RiscPC cmos/clock
Replies: 10
Views: 495

RiscPC cmos/clock

I recently de-batteried my StrongArm RiscPC and replaced it with a super cap - this doesn't seem to have worked. There was very little battery leakage, a couple of greenspots but nothing bad that I could see. The supercap doesn't seem to have worked, I'm not sure of the schematic I just gave it a go...
by dominicbeesley
Wed Jul 15, 2020 10:22 am
Forum: 32-bit acorn hardware
Topic: AKF85 parts
Replies: 0
Views: 179

AKF85 parts

I've been trying to get my RPC working recently and discovered my monitor to be dead. I can't remember if it died before I put it away, about 10 years ago, or not. The little lcd lights up and says the right things. There's nose from the scan coils at 50ish hz but no sign of EHT. So does anyone know...
by dominicbeesley
Mon Jul 13, 2020 2:52 pm
Forum: past all-day virtual ABugs
Topic: All-day 'Virtual' Acorn session #5, Saturday 4th July 2020, 9am - 10pm
Replies: 70
Views: 3226

Re: All-day 'Virtual' Acorn session #5, Saturday 4th July 2020, 9am - 10pm

Thanks again Dave for putting these up. I'm working slowly through all the talks, these are a wonderful collection. I've thoroughly enjoyed Paul's excellent talk!

D
by dominicbeesley
Mon Jul 13, 2020 10:47 am
Forum: 32-bit acorn hardware
Topic: StrongARM CPU refurbish
Replies: 8
Views: 481

Re: StrongARM CPU refurbish

Thanks. I've got a reasonable array of rework gear. Twisting of does have its place for electolytics but only as a last resort. I didn't think rpc motherboards were particularly prone to pads lifting. I'll probably just hot air them with suitable sheilding
by dominicbeesley
Sun Jul 12, 2020 6:38 pm
Forum: 32-bit acorn hardware
Topic: StrongARM CPU refurbish
Replies: 8
Views: 481

Re: StrongARM CPU refurbish

Good work. Is this something that is common. I have a StrongArm machine that was unreliable last time i tried it 5 years or so ago.... since then the battery had leaked so i need to do a full restoration. I will check the caps!
by dominicbeesley
Thu Jul 09, 2020 11:50 am
Forum: programming
Topic: MOS Buffer numbers
Replies: 6
Views: 277

Re: MOS Buffer numbers

Thanks all, If I get a chance (between my DIY tasks) this weekend I'll try and get a bit further. It's a shame if all the OS hooks don't work properly for the buffers idea as it will mean a lot of extra work (and mucking around with extended vectors or grabbing a page of workspace which I'd like to ...
by dominicbeesley
Wed Jul 08, 2020 4:01 pm
Forum: programming
Topic: MOS Buffer numbers
Replies: 6
Views: 277

Re: MOS Buffer numbers

Thanks. I'll update the wiki when it's working.

I wound have thought there was more hardware and software that used the buffer system but maybe I'm wrong
by dominicbeesley
Wed Jul 08, 2020 11:56 am
Forum: programming
Topic: MOS Buffer numbers
Replies: 6
Views: 277

MOS Buffer numbers

I'm slowly hacking away at getting the Paula/Blitter boards to work from BASIC and I'd like to make them work as closely as possible to the original SOUND system To that end I think I'm going to add some extra input buffers by intercepting INSV/REMV/CNPV but I'm not sure what buffer numbers to use. ...
by dominicbeesley
Mon Jul 06, 2020 1:24 pm
Forum: past all-day virtual ABugs
Topic: All-day 'Virtual' Acorn session #5, Saturday 4th July 2020, 9am - 10pm
Replies: 70
Views: 3226

Re: All-day 'Virtual' Acorn session #5, Saturday 4th July 2020, 9am - 10pm

I look forward to watching the videos, I'm afraid this one completely passed me by, though this time I couldn't attend but I don't want to miss any future events. Is there any way we could easily make a single announcement thread for these, those interested could then subscribe to that thread and no...
by dominicbeesley
Sun Jul 05, 2020 6:47 pm
Forum: acorn atom and acorn system series
Topic: Connect a 80287 to a 6502 computer?
Replies: 12
Views: 535

Re: Connect a 80287 to a 6502 computer?

I will follow with interest - I have been looking at something like this but I didn't think of the intel chips!

D
by dominicbeesley
Thu Jul 02, 2020 12:21 pm
Forum: 8-bit acorn software: other
Topic: Why was BBC BASIC so fast?
Replies: 35
Views: 1431

Re: Why was BBC BASIC so fast?

the Basic is tokenised and expressions are converted to an RPN format and partially compiled programs into machine code before running them Neither of these are true as far as I'm aware from doing a line-by-line port the expressions are evaluated in the order they are written (by a quite clever and...
by dominicbeesley
Sat Jun 27, 2020 5:50 pm
Forum: 8-bit acorn hardware
Topic: BBC Buggy LDR
Replies: 1
Views: 173

Re: BBC Buggy LDR

Just seen this - I would buy a handful from ebay GL5506 looks like a likely candidate, you don't say how much light but I would have thought they are unlikely to be too critical?

D
by dominicbeesley
Sun Jun 21, 2020 8:39 pm
Forum: programming
Topic: Which 8 bit computers could run BBC BASIC?
Replies: 25
Views: 1102

Re: Which 8 bit computers could run BBC BASIC?

My 6809 port comes out like this: 20200621_203331.jpg And 6309 a touch quicker 20200621_203603.jpg YMMV especially if you're doing a lot of trig! Sorry for the photo quality EDIT: I forgot to disable interrupts so these are a bit slower than they should be. I've been told to sit down and stop playin...
by dominicbeesley
Fri Jun 19, 2020 11:56 am
Forum: 8-bit acorn emulators
Topic: B-Em
Replies: 498
Views: 46444

Re: B-Em

Cool, I've not had a look at the trace thing yet - it probably doesn't quite work as it stands but shouldn't take too much to fix up - I'm still using Dave's decode6502. This evening or weekend I'll get the trace thing tested and try the suggestions (registers first, tab separators) and continue to ...
by dominicbeesley
Fri Jun 19, 2020 12:10 am
Forum: 8-bit acorn hardware
Topic: A blitter for the beeb?
Replies: 129
Views: 15568

Re: A blitter for the beeb?

That's pretty much the idea. I've got something very basic working this evening and had captain pugwash playing with sampled pipes. I've got some issues with clicks when samples stop and start but I'm not sure if that is down to the emulator I'm working in but we'll find out when I try it on real ha...
by dominicbeesley
Fri Jun 19, 2020 12:07 am
Forum: 8-bit acorn emulators
Topic: B-Em
Replies: 498
Views: 46444

Re: B-Em

Thanks Dominic,

I'll see if I can get that installed at least on my Linux machine. I'm not sure that the mingw/msys has that option though.

Coeus, I've fixed a couple more things and merged in the vdfs root in config file change too.

D

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