Search found 286 matches

by tom_seddon
Fri Jul 19, 2019 10:34 am
Forum: emulators
Topic: Reads of write-only CRTC / ULA registers -- tests
Replies: 23
Views: 365

Re: Reads of write-only CRTC / ULA registers -- tests

I think these registers are always readable on the beeb, as it uses the programmable vsync length functionality, and R12/R13 are readable on any 6845 that supports that. Not all datasheets cover all types of 6845, but i've got one somewhere, that I'll try to find later, that covers a few. Or you can...
by tom_seddon
Tue Jul 16, 2019 11:32 pm
Forum: software: other
Topic: Good book or guide on how FS ROMs work
Replies: 6
Views: 226

Re: Good book or guide on how FS ROMs work

The BeebLink filing system ROM might also serve as an example: https://github.com/tom-seddon/beeblink/ ... eblink.s65

—Tom
by tom_seddon
Mon Jul 15, 2019 12:06 pm
Forum: upcoming and recent events & exhibitions
Topic: Acorn World and ABUG meetup, Cambridge 20-22nd September 2019
Replies: 64
Views: 1815

Re: Acorn World and ABUG meetup, Cambridge 20-22nd September 2019

Looks like there'll still be room! - I'd like a full size table for 3 days please.

--Tom
by tom_seddon
Sun Jul 07, 2019 6:45 pm
Forum: hardware
Topic: Master very poor video output
Replies: 5
Views: 231

Re: Master very poor video output

Interesting, thanks - I wonder if all these cheap supermarket TVs use the same hardware? My Master does work fine via SCART with my SCART CRTs and my Samsung LCD TV, so perhaps there's just something slightly out of spec or marginal about the output. I've got a B (with a HD6845) as well as my Master...
by tom_seddon
Sat Jul 06, 2019 11:31 pm
Forum: hardware
Topic: Master very poor video output
Replies: 5
Views: 231

Re: Master very poor video output

I have similar issues with my Master with one of my TVs. Looks like your Mode 7 pic has wobbly output like mine (the wobbliness shimmers, on my Master... it's really quite distracting, and no good for anything more than quick tests), and there's wonky output from interlaced modes too. (The TV in que...
by tom_seddon
Sat Jul 06, 2019 11:12 pm
Forum: software: other
Topic: Basic BASIC Question
Replies: 28
Views: 651

Re: Basic BASIC Question

It's rather difficult to say with so little context - but 224 was the commonly-used character code for the first user-defined graphic character on the model B, so perhaps these lines select a user-defined graphic character for later printing... --Tom P.S. by default (and you could tweak this - but f...
by tom_seddon
Wed Jun 12, 2019 1:24 am
Forum: general
Topic: Today I received.....
Replies: 5275
Views: 400071

Re: Today I received.....

@danielJ WTF did you edit that for ?? :arrow: No bad word's, I said pics years before Madonna's coffee table volume & a lady in a gif playing with her ... Felis catus :lol: Cart if any interest : Edit Pic added as old browser on mobby phone won't do it :( That's for the Psion Organiser II: https://...
by tom_seddon
Tue Jun 04, 2019 11:56 pm
Forum: community projects
Topic: Advanced User Guide (Remastered)
Replies: 16
Views: 664

Re: Advanced User Guide (Remastered)

Nice work! Great to see the key numbers fixed, and for OSFILE to finally have the right address :) - I suspect this PDF will have a permanent home in my Acrobat recent files list... I have found one new issue - on page 257, 10.2 section c should real "Locations &FD and &FE". --Tom P.S. A remastered ...
by tom_seddon
Mon May 27, 2019 4:02 pm
Forum: hardware
Topic: Page ROM/RAM
Replies: 28
Views: 984

Re: Page ROM/RAM

The results of this scan are stored in &2A1->&2B0. This will hold the ROM type (eg &82), or 0 if no ROM (or duplicate) is detected. So tools like *ROMS could use this to skip printing of the duplicates. (That's how my RAM Manager I wrote BITD worked, anyway). Out of interest, what does the OS do to...
by tom_seddon
Mon May 20, 2019 11:26 pm
Forum: hardware
Topic: Replacement Keyboard LEDs
Replies: 8
Views: 463

Re: Replacement Keyboard LEDs

The shift lock and tape LEDs stopped working on my model B about 20 years ago, and I only got round to finally fixing them this year. Just needed some dry joints resoldering - looked like all 3 LEDs are the originals. Of course, the caps lock LED has had a lot of use over the years. Shift lock and t...
by tom_seddon
Mon May 20, 2019 6:38 pm
Forum: software: new games
Topic: Doom?
Replies: 123
Views: 5937

Re: Doom?

Doom should work with BeebLink, I'd hope - there's a somewhat arbitrary 16 MByte file size, mainly so *INFO output can print the size in 6 digits, but I think the Doom WADs are smaller than that. If Doom uses OSBGET to read the WAD files, performance will be extremely poor, but performance with OSGB...
by tom_seddon
Tue May 14, 2019 11:53 pm
Forum: emulators
Topic: 50 fps on b-em?
Replies: 18
Views: 716

Re: 50 fps on b-em?

What I've done for b2 is run the BBC emulation on a second thread, and have it emit a sort of video data packet every cycle, containing hsync state, vsync state, and RGB data for 8 x Mode 0 pixels - this is supposed to very roughly correspond to sampling the RGB plug's pins. The emulator thread writ...
by tom_seddon
Tue May 14, 2019 10:52 pm
Forum: archive requests
Topic: Electron Le Box by PACE
Replies: 5
Views: 270

Re: Electron Le Box by PACE

See also, perhaps, WE's Le Modem: http://www.computinghistory.org.uk/det/ ... -Le-Modem/ - always used to wonder why they called it that. (And, also, why they seemed to keep selling it, even though it never got BT approved...)

--Tom
by tom_seddon
Sat May 11, 2019 12:09 am
Forum: projects
Topic: BeebLink
Replies: 45
Views: 2587

Re: BeebLink

Oh, excellent - thanks for the report! Your pi must be newer than mine, as it doesn't work for me ;) (But it fails in a way that makes me wonder whether perhaps the Linux version I've got is just too old and/or weird - which wouldn't be surprising, as my Pi is a single core 700MHz ARMv6, and I've ha...
by tom_seddon
Fri May 10, 2019 7:58 pm
Forum: projects
Topic: BeebLink
Replies: 45
Views: 2587

Re: BeebLink

Regarding the bootstrap process, maybe something went awry when I copy-and-pasted the code into the docs, or maybe I broke something - I'll have a look :oops: The server does run on Linux, but you have to build it from source: https://github.com/tom-seddon/beeblink#building-it-yourself I've never tr...
by tom_seddon
Fri May 10, 2019 4:37 pm
Forum: projects
Topic: BeebLink
Replies: 45
Views: 2587

Re: BeebLink

If I get some time (and I should really finish Arcflash and the "Ultimate Elk Upgrade" board first) I'll see if I can get BeebLink to work with my board. I imagine it's just a matter of using different serial port registers -- my board just acts like the Beeb's serial port, except the tx/rx status ...
by tom_seddon
Fri May 10, 2019 3:37 pm
Forum: projects
Topic: BeebLink
Replies: 45
Views: 2587

Re: BeebLink

Bit late to the party, but... I bought a Tube Serial adaptor from Chris about 2 months ago. Chris had mentioned BeebLink when I bought it, but it didn't support the Tube Serial back then. I finally got around to building it yesterday, and noticed this morning that BeebLink now supported it, so it w...
by tom_seddon
Wed May 08, 2019 1:42 am
Forum: hardware
Topic: Useful Electron ROMs?
Replies: 6
Views: 352

Re: Useful Electron ROMs?

You could use JGH's relocatable modules system to create a ROM bank that's effectively got multiple ROMs in it: http://mdfs.net/Software/BBC/Modules/ - or, if (like me) you prefer to work on the PC, you can use my smload_join Python script to do the merging. Either way, this gives you the option of ...
by tom_seddon
Sun May 05, 2019 10:30 pm
Forum: projects
Topic: BeebLink
Replies: 45
Views: 2587

Re: BeebLink

Sadly that wasn't the end of my GitHub release woes :lol: - so I've decided decided to retire AVR support, and BeebLink now officially only works with the Tube serial adapter + purple board. I don't use an AVR dongle any more, and I don't think anybody else ever did, and it was taking the CI server ...
by tom_seddon
Sat Apr 27, 2019 11:06 pm
Forum: hardware
Topic: Tuning an old BBC Master
Replies: 8
Views: 493

Re: Tuning an old BBC Master

Where do you put the resistor and diode though? :) - wrap them up in some electrical tape, and the results are pretty neat.
IMG_0429.JPG
--Tom
by tom_seddon
Sat Apr 27, 2019 10:42 pm
Forum: hardware
Topic: Tuning an old BBC Master
Replies: 8
Views: 493

Re: Tuning an old BBC Master

Contact cleaner fixed my Master's dodgy keys. Remove key cap, press key, spray contact cleaner in, press a few times, leave to dry for a while (as the stuff will probably have gone everywhere). I used a multimeter (in continuity mode) to test the result - when the switch is working, the two correspo...
by tom_seddon
Fri Apr 19, 2019 9:58 pm
Forum: projects
Topic: BBC Micro and Acorn Electron demo effects
Replies: 69
Views: 3458

Re: Acorn Electron demo effects

Who'd ever have thought the Electron had it in it!

Would the screen address granularity be good enough to create something like one of the effects here? - http://norecess.cpcscene.net/the-elders-scrollers.html

--Tom
by tom_seddon
Thu Apr 18, 2019 2:16 pm
Forum: projects
Topic: BeebLink
Replies: 45
Views: 2587

Re: BeebLink

BeebLink now supports cmorley's Tube serial adapter in comms mode, meaning installation and setup is much simplified, and max throughput is improved in most cases* - It's enough of an improvement over the AVR setup that it's now the preferred link type, even though strictly speaking this is beta fun...
by tom_seddon
Mon Mar 25, 2019 2:09 pm
Forum: software: new games
Topic: Stunt Car Racer for BBC Master
Replies: 60
Views: 3429

Re: Stunt Car Racer for BBC Master

A minor Stunt Car Racer update has been released: version 1.1. This fixes a couple of issues with the first release, and adds ADFS compatibility. You can download it from the site: https://bitshifters.github.io/posts/prods/bs-scr-beeb.html Stunt Car Racer now also comes as an ADFS image: https://bit...
by tom_seddon
Sun Mar 24, 2019 10:40 pm
Forum: software: other
Topic: Climbing Man illusion (BBC BASIC)
Replies: 11
Views: 575

Re: Climbing Man illusion (BBC BASIC)

I assume OSBYTE 25 came as part of the Master's OS? - it's documented in the Master Reference Manual, part 1 (page D.2-28). You can reset character definitions in blocks of 32 (i.e., 256 bytes'-worth), according to the value of X: 0 = 32-255 1 = 32-63 2 = 64-95 3 = 96-127 (etc.) 7 = 224-255 Accordin...
by tom_seddon
Tue Mar 19, 2019 12:31 am
Forum: emulators
Topic: Filing system tests and B-Em
Replies: 5
Views: 659

Re: Filing system tests and B-Em

I had to update my FS tester again, as I noticed an issue running Stunt Car Racer on BeebLink that it wasn't catching. (OSFILE A=0 should update the parameter block with length/attributes - and it now tests for this.) While I was doing stuff to it, I fixed it up to make it ADFS-friendly, changed its...
by tom_seddon
Fri Mar 15, 2019 5:56 pm
Forum: software: new games
Topic: Stunt Car Racer for BBC Master
Replies: 60
Views: 3429

Re: Stunt Car Racer for BBC Master

Thanks for the report - looks like I missed that bit out when updating the manual text that goes on the disc... :oops:

This oddity was inherited from the C64 version - sounds like the C64 suffers quite badly from ghost keys - and we tried to leave the gameplay code alone.

--Tom
by tom_seddon
Fri Mar 15, 2019 4:30 pm
Forum: development tools
Topic: Ghidra disassembler
Replies: 4
Views: 326

Re: Ghidra disassembler

I've been giving Ghidra a go, and I'm not finding it very good for 6502 stuff (yet?). The main problem I've got with it is that when it finds an instruction with a register+constant addressing mode, if it can figure out the value of the register, it treats the effective address as the byte of intere...
by tom_seddon
Tue Mar 12, 2019 12:26 am
Forum: community projects
Topic: Earliest examples of each machine?
Replies: 41
Views: 6114

Re: Earliest examples of each machine?

Issue 3 Beeb with serial number ICL 003253 for sale on eBay: https://www.ebay.co.uk/itm/Acorn-BBC-B- ... 4159619153

--Tom
by tom_seddon
Mon Mar 11, 2019 5:27 pm
Forum: software: other
Topic: Drawing a circle in BBC BASIC
Replies: 50
Views: 2387

Re: Drawing a circle in BBC BASIC

I've always found BBC BASIC more convenient as text too, since I'm almost always looking at it on the PC. To do this on OS X, I use BBCBasicToText , in conjunction with wget. Use wget to download the tokenized data and print it to stdout; pipe the result through BBCBasicToText, and out comes text. F...