Search found 2834 matches

by jgharston
Sat Jan 20, 2018 5:05 pm
Forum: hardware
Topic: Connecting SEGA Mega Drive controllers to the beeb
Replies: 4
Views: 175

Re: Connecting SEGA Mega Drive controllers to the beeb

tricky wrote:Unfortunately, when I finished wiring the prototype, it was wrong!
Well, you were calling Fate on your head when you posted I am still in the process of building a proper prototype, but it shouldn't work! :)

What's the LPSTB hack? I've heard of it, but never encountered any information.
by jgharston
Sat Jan 20, 2018 1:53 am
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 54
Views: 1293

Re: SpectROM - Speccy emulator for the Pi co-pro

Edit to add: A nice little trick which comes for free though, is only output a packet at all if the byte being stored is different from the byte that's already there. That could even help a routine like this enormously. I believe (without going back to Sheffield to check) that's what Speculator on ...
by jgharston
Sat Jan 20, 2018 1:47 am
Forum: programming
Topic: JGH's Docs.Comp.BBC.MemAddrs
Replies: 2
Views: 97

Re: JGH's Docs.Comp.BBC.MemAddrs

I was going to post: is the Wiki article clearer, but there's actually nothing much there! It's regarding http://mdfs.net/Docs/Comp/BBC/MemAddrs. What's bit 20 of the address for in this scheme? Nothing, just like "what's bit 4 in SHELA I/O addresses?". In the summary table towards the end...
by jgharston
Fri Jan 19, 2018 9:30 pm
Forum: upcoming and recent events & exhibitions
Topic: ABug NORTH User Group meeting | 19-21 JAN 2018 | MANCHESTER *BOOKING INFO*
Replies: 110
Views: 3956

Re: ABug NORTH User Group meeting | 19-21 JAN 2018 | MANCHESTER *BOOKING INFO*

Recently, I've had access to an EMR midi adaptor. I've tried to get that working along with a midi keyboard and a sound module but I haven't managed to figure it out as yet - maybe someone who knows what they're doing can have a play and get things going. I did an updated backup to my Compact, and ...
by jgharston
Thu Jan 18, 2018 11:38 pm
Forum: upcoming and recent events & exhibitions
Topic: ABug NORTH User Group meeting | 19-21 JAN 2018 | MANCHESTER *BOOKING INFO*
Replies: 110
Views: 3956

Re: ABug NORTH User Group meeting | 19-21 JAN 2018 | MANCHESTER *BOOKING INFO*

1024MAK wrote:Why can you never find what you want when your time is limited... :shock: :(

Do I pack everything up now, or do I plan on waking up early enough tomorrow to do it plus everything else I need to do...? :)
by jgharston
Thu Jan 18, 2018 11:36 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 54
Views: 1293

Re: SpectROM - Speccy emulator for the Pi co-pro

[*] LDIR can do a block copy in 21 T-states per byte. Seems a bit slow, and I'm not really sure if it was used much (I think they tended to prefer an unrolled bunch of LDIs, 16 T-states each - still a bit slow). You could still optimise this on the host by outputting packets where the Beeb screen m...
by jgharston
Thu Jan 18, 2018 8:10 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 54
Views: 1293

Re: SpectROM - Speccy emulator for the Pi co-pro

(Annoyingly, OSBYTE &79 works differently on a B/B+ than it does on the Master I've been using for testing...) Which issue is that? The only difference is that the Master keyboard has 16* columns to the Beeb's 10 columns. (*ok, technically 13 columns) RISC OS (and I think the Elk) don't impleme...
by jgharston
Thu Jan 18, 2018 8:00 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 54
Views: 1293

Re: SpectROM - Speccy emulator for the Pi co-pro

There's a handful of screen dumps here as within Spectrum SNA snapshots. The screen data starts at byte 27 and continues for &1B00 bytes. GrabScrn will extract the screen data from a SNA or SNP shapshot, and ZXDisp will display the screen memory from within a SNA or SNP snapshot.
by jgharston
Wed Jan 17, 2018 2:03 am
Forum: hardware
Topic: Plus1 Slogger ROM without cart joy interface?
Replies: 6
Views: 184

Re: Plus1 Slogger ROM without cart joy interface?

Is it possible to use the Slogger Expansion ROM in the Electron's Plus1 without also using the joystick interface that plugs into the cart socket? Specifically, can the *JOYSTICK command be used with the regular plus1 joystick ports to remap to keys? The Plus 1 *don't* have any joystick ports, regu...
by jgharston
Wed Jan 17, 2018 1:43 am
Forum: emulators
Topic: MAME: Click (and other large ROMs)
Replies: 6
Views: 216

Re: MAME: Click (and other large ROMs)

Link? http://stardot.org.uk/forums/viewtopic.php?f=32&t=11795&p=148353#p148353 It has common code at &1f80, &3f80, &5f80, &7f80. Ta. Yes, it looks like it uses &A000 as a RAM copy of the bank paging register (the equivalent of &F4), and uses &FCFC as the paging r...
by jgharston
Wed Jan 17, 2018 1:30 am
Forum: upcoming and recent events & exhibitions
Topic: ABug NORTH User Group meeting | 19-21 JAN 2018 | MANCHESTER *BOOKING INFO*
Replies: 110
Views: 3956

Re: ABug NORTH User Group meeting | 19-21 JAN 2018 | MANCHESTER *BOOKING INFO*

At the moment I don't know if I'll be arriving Friday evening or Saturday morning, as I'm supposed to be in both Sheffield and Scarborough on Friday, and still haven't had it confirmed if the Scarborough is actually happening or not.

It probably means that all I'll be bringing will be my Compact.
by jgharston
Wed Jan 17, 2018 1:26 am
Forum: emulators
Topic: BeebEm ADFS disc access bug?
Replies: 14
Views: 366

Re: BeebEm ADFS disc access bug?

It's reassuring to hear it isn't just me! Just to be clear though, - this bug appears to be totally repeatable (if using this specific floppy image) Wait a bit, you said "accessing hard disk images". - and it doesn't actually relate to the hard disc at all. You don't need to switch hd sup...
by jgharston
Wed Jan 17, 2018 1:24 am
Forum: emulators
Topic: MAME: Click (and other large ROMs)
Replies: 6
Views: 216

Re: MAME: Click (and other large ROMs)

Pernod wrote:Does anyone have any technical details on how Click paged it's 32K ROM and 32K RAM? From a quick look at the ROM it looks like it's in 8K chunks and maybe paged with writes to &FCFC.


Link?
by jgharston
Wed Jan 17, 2018 1:23 am
Forum: software: other
Topic: Accessing ROMs from the 6502 second processor
Replies: 8
Views: 351

Re: Accessing ROMs from the 6502 second processor

"I would like to make 2nd processor compatible" 2nd processor compatible, or 6502 second processor compatible? If 2nd processor compatible, that means you're working from BASIC. If 6502 second processor compatible, that means you're restricting yourself to just the 6502 second processor. (...
by jgharston
Tue Jan 16, 2018 2:18 am
Forum: for sale / freebies
Topic: VideoNuLA boards
Replies: 43
Views: 3785

Re: VideoNuLA boards

Has anybody used the nULA board in a Master Compact? I have a floppy drive mounted internally in my Compact, before I look for my soldering iron, is the board likely to fit?
Image
by jgharston
Tue Jan 16, 2018 2:14 am
Forum: for sale / freebies
Topic: VideoNuLA boards
Replies: 43
Views: 3785

Re: VideoNuLA boards

The post on Spectrum attirbute mode reminds me of a discussion I was having with RobC earlier. The VideoNuLA support ROM allows to select the extended display features with MODE/VDU 22. It currently uses MODEs &60-&68 as a straight sequence of numbers. I mentioned that it would match the nat...
by jgharston
Tue Jan 16, 2018 1:47 am
Forum: emulators
Topic: BeebEm ADFS disc access bug?
Replies: 14
Views: 366

Re: BeebEm ADFS disc access bug?

You're not alone. Every now and then when I use ADFS to access a hard drive image and get Bad directory when mounting. I can't rememebr the exact circumstances when it happens, and I can't remember what I did to fix it. I wonder if it might be when I copy the image to another machine, update it, the...
by jgharston
Sun Jan 14, 2018 6:47 pm
Forum: programming
Topic: 32k memory management for dummies
Replies: 28
Views: 760

Re: 32k memory management for dummies

crj wrote:I remain unsure what the correct behaviour is if someone attempts to select filing system 0...

Filing system zero ois defined to not exoist. It means "no filing system"
by jgharston
Sun Jan 14, 2018 6:37 pm
Forum: software: other
Topic: BBC Basic for Z80
Replies: 26
Views: 1124

Re: BBC Basic for Z80

How do you normally gry stuff from the internet into your beeb? Do that.
by jgharston
Sun Jan 14, 2018 6:31 pm
Forum: emulators
Topic: Variations on OSGBPB
Replies: 4
Views: 164

Re: Variations on OSGBPB

What's the history? Blame warm silence. Why does it do it that way? Blame warm silence.
Whatever you do, note that in the vdfd example you give you are not calling osgbgb, you are calling the osgbgb emulator trap.
And note line 4690
by jgharston
Sun Jan 14, 2018 6:27 pm
Forum: emulators
Topic: Variations on OSGBPB
Replies: 4
Views: 164

Re: Variations on OSGBPB

Also, the WSS emulator trap &03 &02 for OSGBPB implements call 9 diffrrenyly to the standard, as does the Acorn emulator trap &93. See http://mdfs.net/Docs/Comp/6502/EmulatorOp
When implementing these emulator ttraps or calling them you have adhere yo these exceptions.
by jgharston
Sun Jan 14, 2018 6:15 pm
Forum: hardware
Topic: SpectROM - Speccy emulator for the Pi co-pro
Replies: 54
Views: 1293

Re: SpectROM - Speccy emulator for the Pi co-pro

A good yrdt would be running z80 BBC basic for the spectrum on it.
Ytft??? Yedt. No t4sy
Gtrr
Tedy
5esdt
Test
God, they font make these thing in any way eassy to type on do they?
by jgharston
Sun Jan 14, 2018 5:56 pm
Forum: programming
Topic: Filing system testing, BASIC, line numbers and version control
Replies: 9
Views: 187

Re: Filing system testing, BASIC, line numbers and version control

I'm on s tablet so forgive the typing.

That's the standard method, as used in my test progtasms at
http://mdfs.net/Software/BBCBasic/Testing/

OK=_true
On error ok=false
If ok then do something
by jgharston
Tue Jan 09, 2018 9:30 pm
Forum: archive requests
Topic: Tubelink EXROM and UTILRAM
Replies: 20
Views: 350

Re: Tubelink EXROM and UTILRAM

*CODE was definitely there in OS 1.20 . I remember it fondly from my earliest attempts at hacking 6502 assembler, before I had sideways RAM and could do things properly. (-8 I'm pretty sure it wasn't in OS 0.10, but have no idea whether or not it was in OS 1.00 . It's in OS 1.00. OS 1.20 is almost ...
by jgharston
Tue Jan 09, 2018 9:25 pm
Forum: hardware
Topic: P.R.E.S. AP5 - Original and Re-Design
Replies: 253
Views: 15956

Re: P.R.E.S. AP5 - Original and Re-Design

I can have a stab at answering these questions... - ADFS 1.00, which has SCSI code but has page at &1D00 (and which has hardly any commands) - ADFS 1.35, which is E00, patched by AlanD to include IDE code (but not SCSI), and which seems to have about the top 3.5k blank (not 4k) - ADFS 3.31, als...
by jgharston
Tue Jan 09, 2018 9:18 pm
Forum: off-topic
Topic: online study?
Replies: 25
Views: 751

Re: online study?

any maths students, care to comment on how tough these 2 papers are? http://www.cl.cam.ac.uk/admissions/undergraduate/admissions-test/sample-test.pdf http://www.cl.cam.ac.uk/admissions/undergraduate/admissions-test/sample-test-2.pdf WOW! They take me back. In upper sixth we had a Maths Study Weeken...
by jgharston
Tue Jan 09, 2018 9:04 pm
Forum: programming
Topic: 32k memory management for dummies
Replies: 28
Views: 760

Re: 32k memory management for dummies

There isn't a perfect solution to this as there does not appear to be an API to say "select filing system X" where the filing system could be anything at all. Yes there is, service call &12 ( link ): A%=143:X%=18:Y%=filingsystemnumber:CALL OSBYTE If you need to be able to select TAPE/...
by jgharston
Tue Jan 09, 2018 8:44 pm
Forum: archive submissions
Topic: Misc BBC/Electron Roms, for checking
Replies: 32
Views: 1624

Re: Misc BBC/Electron Roms, for checking

Wouter Scholten wrote:So the Challenger 3 DD BIOS v1.01 + DDCPM v1.01.fdi is the one I was curious about...

Is it any different to these?

At that link is also RdDDCPM and WrDDCPM which read and write DDCPM disk images.
by jgharston
Tue Jan 09, 2018 8:38 pm
Forum: archive submissions
Topic: Misc BBC/Electron Roms, for checking
Replies: 32
Views: 1624

Re: Misc BBC/Electron Roms, for checking

Now if only I could make a working DD CP/M format floppy....the format program allows me to select to format double density, performs the format ok, but when I try and catalog the disk, it reports bad sectors."[/i] FormDDCPM should format a disk to Slogger DDCPM format, single density for the ...

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