Search found 845 matches

by crj
Sat Jul 27, 2019 7:52 pm
Forum: software
Topic: API for IP network interface drivers ; WireGuard
Replies: 3
Views: 144

Re: API for IP network interface drivers ; WireGuard

Hmm. Unfortunately all the links in that page have gone stale in the fifteen(!) years since the project was last touched.

You don't happen to have copies of any useful code or documentation, do you?
by crj
Sat Jul 27, 2019 4:59 pm
Forum: software
Topic: API for IP network interface drivers ; WireGuard
Replies: 3
Views: 144

API for IP network interface drivers ; WireGuard

Hi all - been away for a while, but thought I'd just dip my toes back in. (-8 Is it possible to write custom interface drivers for the RISC OS IP stack, i.e. to write a relocatable module that provides an interface foo0 which can be used just like an Ethernet interface? If so, does anyone know of an...
by crj
Wed Feb 06, 2019 1:01 am
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

Say you intercepted BYTEV that way. Then an EVENTV claimant calls OSBYTE in the middle of a foreground OSBYTE call. /-8
by crj
Tue Feb 05, 2019 12:54 am
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

Ok, here's a first attempt. It appropriates INDV3 for use by the daisy-chaining. My main misgiving about that approach is that it's not re-entrant. If something uses that mechanism in an interrupt handler while another thing is trying to use it in the foreground, there will be fireworks. A more min...
by crj
Tue Feb 05, 2019 12:49 am
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

One example where it would obviously go seriously wrong is if you trapped BRKV that way. Surely not. The OS selects the current language before dispatching via BRKV. Indeed, so there's a risk this could happen: BRK OS selects current language then does JMP (BRKV) BRKV calls the XBRKV extended vecto...
by crj
Mon Feb 04, 2019 4:22 pm
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

One example where it would obviously go seriously wrong is if you trapped BRKV that way. Fortunately, you can just handle paged ROM service call 6 instead. On reflection, looking through the other vectors I can see: Filing system vectors - OK Vectors that might be called under interrupt - OK Vectors...
by crj
Mon Feb 04, 2019 1:22 am
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

Then you just finish by jumping to the address previously in the non-extended vector. The problem, as I mentioned, is that this means the previous claimant is called with your ROM selected, not the one that was selected when the vector was invoked. (The previous ROM is restored correctly when the f...
by crj
Sun Feb 03, 2019 1:34 am
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

If one was designing a mechanism from scratch, I imagine the sensible solution would be something like: Allow a page for extended vector chains. Divide it up into 64 entries, each of which is ROM number, address in ROM, address of next entry. That would allow the space to be used as linked lists of ...
by crj
Fri Feb 01, 2019 4:26 pm
Forum: software: other
Topic: Extended vectors - huh?
Replies: 17
Views: 1560

Re: Extended vectors - huh?

Almost a year later, I'm revisiting this issue. It seems to me you can get a considerable distance by having a primitive for "JMP to code in different ROM". On reflection, I'm kinda surprised that primitive was never made public in the way OSRDRM/OSRDSC was. Rummaging in JGH's collection of OS ROMs ...
by crj
Mon Jan 07, 2019 1:59 pm
Forum: hardware
Topic: Sideways RAM on the BBC Micro
Replies: 52
Views: 3933

Re: Sideways RAM on the BBC Micro

Hmm. Those parts are £10.52+VAT at Mouser in quantities of 100. Is that eBay price cheap, or too cheap? If it's a legitimate price, I imagine the ROHM part can be got more cheaply, too. More of an issue, although that Cypress device is 5V-tolerant, its Voh1 is only 2.4V. While fine for TTL, that's c...
by crj
Sun Jan 06, 2019 10:53 pm
Forum: hardware
Topic: Sideways RAM on the BBC Micro
Replies: 52
Views: 3933

Re: Sideways RAM on the BBC Micro

(Resurrecting an old thread, despite not having been around much recently - hi, folks!) Mmm. Until now, SRAM and EEPROM/Flash have been the main options for such modules, but F-RAM chips are getting larger and cheaper, so I suspect in a few years' time they'll be the natural choice. The only questio...
by crj
Thu Dec 06, 2018 12:48 am
Forum: hardware
Topic: M3000 vs M5000
Replies: 50
Views: 4441

Re: M3000 vs M5000

The version of AMPLE in the Nucleus ROM (I get the impression the previous RAM-resident version was rather simpler) supports words coming from three places: The Nucleus The user program Modules From (25-year-old) memory , Nucleus words are represented by single bytes, whereas others are represented ...
by crj
Tue Jun 12, 2018 12:01 pm
Forum: past events & exhibitions
Topic: ABUG Cambridge Sept 7th-9th 2018 BOOKING THREAD
Replies: 207
Views: 12658

Re: ABUG Cambridge Sept 7th-9th 2018 BOOKING THREAD

helpful wrote:
Tue Jun 12, 2018 1:13 am
the attendee list (actually a table list)
That's a good point. I won't need a table. But I'm still interested in the pay-for-two-days-get-three deal on access to the museum, the out-of-hours socialising, etc. (-8
by crj
Mon Jun 11, 2018 11:42 am
Forum: past events & exhibitions
Topic: ABUG Cambridge Sept 7th-9th 2018 BOOKING THREAD
Replies: 207
Views: 12658

Re: ABUG Cambridge Sept 7th-9th 2018 BOOKING THREAD

Eeek! Sorry, I've been away from the forums for a bit. Many thanks to Boydie for prodding me.

Yes, I'll definitely take a place, please!
by crj
Sun May 13, 2018 7:20 pm
Forum: general
Topic: Maplin Electronics in administration
Replies: 110
Views: 8333

Re: Maplin Electronics in administration

I stuck my nose through the door today. They're still being ridiculously optimistic price-wise. A lot of what's left I wouldn't buy at anything less than 80% discount, but it's only been reduced by 50% so far. Even now, they seem to have their heads in the sand about just how cheaply commodity stuff...
by crj
Tue Apr 24, 2018 4:41 pm
Forum: general
Topic: Today I received.....
Replies: 5409
Views: 417226

Re: Today I received.....

Finally, some melatonin:
DSC_0618.JPG
I'm hoping this will fix my sleep disturbance and give me my life back. If it does, hopefully that in turn will mean more energy devoted to retrocomputing projects. (-8
by crj
Wed Apr 18, 2018 5:24 pm
Forum: software & utilities for the pc, mac or unix
Topic: New Disk Image Editor
Replies: 78
Views: 6167

Re: New Disk Image Editor

Also, remember to translate between BBC filename characters and WinDOS characters Incidentally, it's not stated but I assume it is understood that character 96 in Acorn filenames always maps to ASCII/Unicode character 96 (i.e. backtick) regardless of whether the file is coming from 8-bit or 32-bit ...
by crj
Wed Apr 18, 2018 5:00 pm
Forum: for sale / freebies
Topic: Free, via Twitter: Beeb stuff in Canterbury
Replies: 16
Views: 1546

Re: Free, via Twitter: Beeb stuff in Canterbury

Thanks ever so much, mildlydiverting, for keeping this kit in circulation, especially at such a difficult time for you. Heartily agreed. Thank you for deciding this is worth some precious spoons! If more old computers got rehomed and fewer got sent to landfill by house clearance companies, the worl...
by crj
Wed Apr 18, 2018 4:40 pm
Forum: software & utilities for the pc, mac or unix
Topic: New Disk Image Editor
Replies: 78
Views: 6167

Re: New Disk Image Editor

Also, remember to translate between BBC filename characters and WinDOS characters: # <-> ? . <-> / $ <-> < ^ <-> > & <-> + @ <-> = % <-> ; And special case, as it's nonreversable: WinDOS SPC -> BBC _ As a related headache, what happens when we encounter an Acorn file called CON, LPT1 or similar? Is...
by crj
Wed Apr 18, 2018 4:37 pm
Forum: software & utilities for the pc, mac or unix
Topic: New Disk Image Editor
Replies: 78
Views: 6167

Re: New Disk Image Editor

Any alternatives must start with "what happens with existing systems". So, going back 25 years, "what happens when I use an Acorn system to copy a file from an Acorn filesystem to a DOS disk?" Which, in terms of filenames is: the filename is as close to identical as possible. So, dragging HELLO fro...
by crj
Wed Apr 18, 2018 4:33 pm
Forum: software & utilities for the pc, mac or unix
Topic: New Disk Image Editor
Replies: 78
Views: 6167

Re: New Disk Image Editor

Even if INF files don't make sense, either now or then, it's been around for more 25 years and any system that doesn't support them will have the failing that it doesn't support them. Agreed. As I said: I mean yes, if it's become a de facto standard it has to be supported for interface purposes It ...
by crj
Wed Apr 18, 2018 3:07 pm
Forum: software & utilities for the pc, mac or unix
Topic: New Disk Image Editor
Replies: 78
Views: 6167

Re: New Disk Image Editor

I wonder if we can create something that's backwards compatible. I wonder how many tools currently read the _second_ line of the INF file? OK. Here's the first difficulty we encounter with that idea: what is the "second line" of an INF file? Specifically, does the file use Acorn line endings, host ...
by crj
Tue Apr 17, 2018 10:54 pm
Forum: for sale / freebies
Topic: Free, via Twitter: Beeb stuff in Canterbury
Replies: 16
Views: 1546

Re: Free, via Twitter: Beeb stuff in Canterbury

Quick update on this: the National Videogame Arcade guys visited and took the software, books etc, but I now have about... ten BBC Bs, four masters, and a pile of floppy drives / monitors (3 Cubs, plus other misc ones...) Joining the dots, I'm the "anotherclive" you responded to on Twitter. (-8 I h...
by crj
Tue Apr 17, 2018 10:46 pm
Forum: hardware
Topic: RGB to Component Video
Replies: 5
Views: 587

Re: RGB to Component Video

Careful. You say "RGB Component Phono connectors", but component video over phono (RCA) connectors is seldom RGB. It's much more common for it to be the YPbPr format which is favoured in countries with NTSC. If you're certain you really want RGBS on phonos, you can make up a lead to do that using ju...
by crj
Tue Apr 17, 2018 10:37 pm
Forum: general
Topic: Today I received.....
Replies: 5409
Views: 417226

Re: Today I received.....

If you want the contents of the EPROM chip with the uncovered window not to decay, it's best to cover the window with either a paper label or black insulation tape. Yeah I noticed that. I'm guessing that whatever is/was on it wasn't that important to the previous owner Actually, wouldn't an EPROM b...
by crj
Tue Apr 17, 2018 2:49 am
Forum: software & utilities for the pc, mac or unix
Topic: New Disk Image Editor
Replies: 78
Views: 6167

Re: New Disk Image Editor

Anyone who uses C, C++, or other languages complied to those languages such as Eiffel already gives up any right to talk about proper engineering practice [...] Anyone who's not autistic will understand there is always tradeoff between perfection (which in reality doesn't exist) and practicality in...
by crj
Sat Apr 14, 2018 11:15 pm
Forum: off-topic
Topic: LOL DESCRIPTION
Replies: 612
Views: 69761

Re: LOL DESCRIPTION

The computer end of the lead is a five pin plug so should be compatible with any of the 1980's home computers that had a three, five or seven pin DIN socket.
A 5-pin DIN plug "should" fit a 3-pin DIN socket? Really now?
by crj
Thu Apr 12, 2018 11:53 pm
Forum: hardware
Topic: Soldering and Hotair station options
Replies: 38
Views: 2493

Re: Soldering and Hotair station options

After one 40 pin DIP I'd had enough and bought this: http://cpc.farnell.com/duratool/d00672/desoldering-station-uk-eu-plug/dp/SD01384?mckv=sZ5p7NarZ_dc|pcrid|224654335881|kword||match||plid||pid|SD01384|&CMP=KNC-GUK-CPC-SHOPPING&gclid=EAIaIQobChMIoMf6j4Ct2gIVqbXtCh1GjQnlEAQYASABEgKhYfD_BwE Ooh! Tha...
by crj
Wed Apr 11, 2018 1:14 pm
Forum: programming
Topic: Acorn files on other platforms
Replies: 38
Views: 2511

Re: Acorn files on other platforms

I agree that Python is a pretty good choice for anything amenable to being coded in it. But, although MicroPython is available for embedded systems, I'm not sure it's up to running a 6502 emulation at a sensible speed with small RAM footprint. Meanwhile, C has been around for almost half a century a...
by crj
Wed Apr 11, 2018 12:32 pm
Forum: programming
Topic: Keyboard Buffer
Replies: 6
Views: 723

Re: Keyboard Buffer

It might be more polite and more robust to insert the keystrokes into the buffer. That will work even if someone's installed different buffering code, and means what you insert ends up queued behind anything that's already pending. You could hook into the RTI instruction. If pasting then, before exe...