Search found 1415 matches

by Coeus
Fri Jan 24, 2020 8:01 pm
Forum: hardware
Topic: Difference between perspex panels?
Replies: 6
Views: 216

Re: Difference between perspex panels?

Ah ok, that makes sense. Usual trademark legal rubbish. I'm not in the same state as the BBC one, so I'll update with the board revision later. I do think trademarks serve a useful purpose but to me it is over restrictive to allow a company to assert that the initials that correspond to its name sh...
by Coeus
Sat Jan 18, 2020 12:17 am
Forum: emulators
Topic: MAME: IDE/SCSI and other large storage devices
Replies: 35
Views: 1036

Re: MAME: IDE and other large storage devices

Been doing lots of testing of the IDE interfaces, and everything works great on a Master with ADFS 1.53. But on a BBC B with ADFS 1.33 I can mount the drive and load small programs, but anything like a game will hang during loading and pressing BREAK gives 'Bad Sum', even CTRL-BREAK won't reset thi...
by Coeus
Sat Jan 18, 2020 12:14 am
Forum: emulators
Topic: MAME: IDE/SCSI and other large storage devices
Replies: 35
Views: 1036

Re: MAME: IDE and other large storage devices

- Are writes to the SCSI data bus inverted by IC's 13/14, and reads inverted by IC3? BeebEm doesn't seem to implement this, maybe ADFS detects whether it's inverted? Is it possible that the host adaptor does one inversion and the SCSI controller does another so the net result is no inversion? Or is...
by Coeus
Sat Jan 18, 2020 12:11 am
Forum: emulators
Topic: MAME: IDE/SCSI and other large storage devices
Replies: 35
Views: 1036

Re: MAME: IDE and other large storage devices

There's no such thing as "a SCSI" or "an IDE" image, they are "ADFS disk images". It's irrelevant what hardware ADFS uses, it's just ADFS (or HADFS of L3FS or DOSDISK). It's just a byte-by-byte dump of the file system. As seen by everything in ADFS above the level of the device driver/hardware, yes...
by Coeus
Wed Jan 08, 2020 5:39 pm
Forum: hardware
Topic: Emulating (or obtaining!) an ARM Evaluation System
Replies: 10
Views: 453

Re: Emulating (or obtaining!) an ARM Evaluation System

And B-Em does too. Again I am not sure how accurate the emulation is. I am also not sure what the benefit of making the emulation cycle accurate is. Is this just a technical challenge, something you want to do? Or is there some piece of software you want to run that existing emulators are not suffic...
by Coeus
Mon Jan 06, 2020 11:12 pm
Forum: general
Topic: Graphics Display from the Late 1960s or early 1970s
Replies: 4
Views: 269

Re: Graphics Display from the Late 1960s or early 1970s

the YouTUBE link suggests the text read ‘Computer controlled display' — Google image searching on that led (indirectly)to the image on this page, http://www.chilton-computing.org.uk/ca/literature/annual_reports/p005.htm Which describes it as an IDI display. Steve Thanks. That's interesting. I got r...
by Coeus
Mon Jan 06, 2020 12:52 am
Forum: general
Topic: Graphics Display from the Late 1960s or early 1970s
Replies: 4
Views: 269

Graphics Display from the Late 1960s or early 1970s

This picture is a frame grab from the early 1970s documentary "The Ascent of Man" by Jacob Bronowski, seen talking to camera. Does anyone know what the graphics display is behind him? I don't believe it is the Tetronix 4000 series for which I recently saw an emulator described on here. Screenshot fr...
by Coeus
Sun Jan 05, 2020 2:05 pm
Forum: software: other
Topic: ADFS Versions
Replies: 4
Views: 1475

Re: ADFS Versions

To clarify JGH's list, I believe the IDE versions are not official Acorn releases but versions which have been patched to replace the SCSI driver with one for IDE. On the question of the Solidisk ADFS, Solidisk DFS software in general seemed to have plenty of bugs but I don't remember ADFS 2.1 being...
by Coeus
Wed Jan 01, 2020 6:26 pm
Forum: emulators
Topic: MAME: IDE/SCSI and other large storage devices
Replies: 35
Views: 1036

Re: MAME: IDE and other large storage devices

I'm looking at adding support for IDE devices but as I've never used anything like this on a Beeb I'm not sure what's out there that's worth emulating. Is SCSI already done? AFAIK the interest in IDE was not because the interface is inherently better in any way, just that it was common because of t...
by Coeus
Tue Dec 24, 2019 9:15 pm
Forum: emulators
Topic: Interesting idea for an emulation technique?
Replies: 7
Views: 465

Re: Interesting idea for an emulation technique?

This is an interesting technique and one that has been used elsewhere. For example, when intending to run software intended to run under CP/M there are several different approaches: 1. Produce an emulator for a machine which has a Z80 processor but has specialist hardware attached to some of the I/O...
by Coeus
Thu Dec 19, 2019 11:05 pm
Forum: hardware
Topic: BBC Model B with TurboMMC - what to do when my Beeb asks me to hit "Record"?
Replies: 9
Views: 391

Re: BBC Model B with TurboMMC - what to do when my Beeb asks me to hit "Record"?

ArthurBDD wrote:
Thu Dec 19, 2019 5:14 pm
Coeus wrote:
Thu Dec 19, 2019 3:51 pm
If the game lets you specify the filename you may be able to put :2. on the front to make it save to drive 2 even though drive 0 is current.
Great tip and I'll try to use it - so to confirm, if the file name I want for the savegame is "SAVE", I should type ":2.SAVE", yes?
Yes.
by Coeus
Thu Dec 19, 2019 3:54 pm
Forum: hardware
Topic: BBC Model B with TurboMMC - what to do when my Beeb asks me to hit "Record"?
Replies: 9
Views: 391

Re: BBC Model B with TurboMMC - what to do when my Beeb asks me to hit "Record"?

If the game forces you to use the tape system, then unfortunately you're stuck. Ideally what is needed is for someone to hack the game to allow it to save to disc, but this isn't always possible. If the game has been loaded from disc but tries to save to tape then it must have executed *TAPE or the...
by Coeus
Thu Dec 19, 2019 3:51 pm
Forum: hardware
Topic: BBC Model B with TurboMMC - what to do when my Beeb asks me to hit "Record"?
Replies: 9
Views: 391

Re: BBC Model B with TurboMMC - what to do when my Beeb asks me to hit "Record"?

Then, within the game, you need to find a way to select Drive 2 (this often does exist). If the game lets you specify the filename you may be able to put :2. on the front to make it save to drive 2 even though drive 0 is current. That is a neater solution to making the disc containing the game writ...
by Coeus
Fri Dec 13, 2019 7:34 pm
Forum: general
Topic: Philosophy of Disc Preservation
Replies: 20
Views: 731

Re: Philosophy of Disc Preservation

The whole FlashFloppy/HxC Floppy emulator thing changes that. With FlashFloppy and the Goteks many many more people are popping floppy emulators in rather than using the Datacentre (no longer available) or MMC (why use that when a gotek is nearly as cheap and more compatible?). We're now at a stage...
by Coeus
Tue Dec 03, 2019 1:13 pm
Forum: hardware
Topic: 6502 Assembly on BBC B, what do I need?
Replies: 21
Views: 809

Re: 6502 Assembly on BBC B, what do I need?

As for getting the code on to the Beeb, I use (and recommend) a DataCentre. I also have a TurboMMC device but find it less convenient than being able to chuck stuff on to a USB stick. Mark (Retroclinic) is no longer supplying DataCentre and has open sourced the design in case anyone wants to port i...
by Coeus
Mon Dec 02, 2019 5:46 pm
Forum: hardware
Topic: 6502 Assembly on BBC B, what do I need?
Replies: 21
Views: 809

Re: 6502 Assembly on BBC B, what do I need?

See: viewtopic.php?f=55&t=15476&hilit=hostfs for info on deploying from PC to BBC.
by Coeus
Mon Dec 02, 2019 5:33 pm
Forum: hardware
Topic: 6502 Assembly on BBC B, what do I need?
Replies: 21
Views: 809

Re: 6502 Assembly on BBC B, what do I need?

For 6502 programming in general there is the 6502.org website: http://6502.org/ For specifics to the BBC micro there is some information on how to use OS facilities in the User Guide and more in the Advanced User Guide and the revised version The New Advanced User Guide . There is loads of informati...
by Coeus
Thu Nov 28, 2019 3:54 pm
Forum: off-topic
Topic: The body or the ascent and civilisation of man in question
Replies: 1
Views: 179

The body or the ascent and civilisation of man in question

The death of Dr Jonathan Miller reminded me that I had started to read his book "The Body in Question" not realising this was the book to accompany a TV series of the same name. This series has popped up on YouTube in what seems to be a case of digitising consumer video tape recordings from when it ...
by Coeus
Mon Nov 25, 2019 10:26 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 41
Views: 1498

Re: Odd Peripheral Goings-On With RPi4

Thanks to BigEd, it's now been fixed. The problem seemed to be that without a display attached, the X server wasn't starting, which I understand also runs the keyboard & mouse, and therefore my keybinds mapped to GPIO pins as well. All it needed was hdmi_force_hotplug=1 uncommenting from config.txt...
by Coeus
Mon Nov 25, 2019 10:12 pm
Forum: software: other
Topic: 6502 assembler for Windows/Linux
Replies: 13
Views: 745

Re: 6502 assembler for Windows/Linux

It depends on whether you do a lot of assembler for other microprocessors and want to use the same tool for both. If that's the case one of the multi-processor assemblers might be the answer. For Beeb only then BeebAsm is a really good choice. It runs on both Windows and Linux and has the closest sy...
by Coeus
Wed Nov 20, 2019 10:26 pm
Forum: hardware
Topic: OSWORD &7F on DFS vs MMFS
Replies: 26
Views: 1019

Re: OSWORD &7F on DFS vs MMFS

My interrupt handler wasn't saving the Y register, only A and X because I didn't use Y in a previous version of the code :oops: Apparently DFS didn't care about that but MMFS does. I have a follow up question for you though: does MMFS enable interrupts (CLI) regardless of the fact that they were di...
by Coeus
Wed Nov 20, 2019 10:03 pm
Forum: off-topic
Topic: Google Stadia
Replies: 10
Views: 530

Re: Google Stadia

So on the question of latency, if there are two possible outcomes of a particular situation depending on whether you operate some control could the server end sent both versions and your local machine choose which to display? Obviously one cannot go on like that forever as the number of simultaneous...
by Coeus
Tue Nov 19, 2019 2:37 pm
Forum: off-topic
Topic: Google Stadia
Replies: 10
Views: 530

Google Stadia

I just saw a very brief article on this, Google's in browser gaming. From what I can see it relies on streaming video from the net rather than local rendering, possibly with a local overlay to make the game specific to the player. Anyone know more of have any thoughts on that? I seem remember this h...
by Coeus
Fri Nov 15, 2019 10:22 pm
Forum: software & utilities for the pc, mac or unix
Topic: Proposal for BBC BASIC 'FOR lists'
Replies: 27
Views: 1077

Re: Proposal for BBC BASIC 'FOR lists'

My difficulty with that argument is that several other 'modern' languages do use FOR to indicate general iteration rather than just a sequence: I think in many languages in which this appears you could say that this is syntactic sugar in that it does not enable you to do anything that you could not...
by Coeus
Sat Nov 02, 2019 10:24 pm
Forum: software: other
Topic: Saving with wildcards
Replies: 1
Views: 283

Saving with wildcards

I thought I'd try saving a file with wildcards in the name and got some surprising, at least to me, results. I don't know if these are well known or documented. First for DFS 0.9 (8271): dfs8271.png So this expands the '*' into hashes as if it was about to do some wildcard matching but then saves wi...
by Coeus
Thu Oct 31, 2019 2:49 pm
Forum: hardware
Topic: Master - Hangs on disk command
Replies: 10
Views: 485

Re: Master - Hangs on disk command

Its a little annoying, because if you accidentially mistype a star command, it then tried to access the disk and hangs - you then have to press break. If you don't have a disc drive connected then it is probably best to *UNPLUG the DFS and ADFS filing systems so the system will make no attempt to a...
by Coeus
Wed Oct 30, 2019 8:00 pm
Forum: hardware
Topic: Master - Hangs on disk command
Replies: 10
Views: 485

Re: Master - Hangs on disk command

Is there any reason to suppose the behaviour with no disc drive connected should match the behaviour with the drive connected but no disc in it? I would be surprised to find any emulator having set out to emulate the drive disconnected condition. When the disc has been ejected it will almost certain...
by Coeus
Wed Oct 30, 2019 7:47 pm
Forum: software & utilities for the pc, mac or unix
Topic: Greaseweazle - £2 disc archiver!
Replies: 9
Views: 1175

Re: Greaseweazle - £2 disc archiver!

I checked the project linked to but it is not immediately obvious what is done in hardware and what in software. Do the flux level archivers have a common mode of operation? How does it differ from the obvious of take the signal from the head of a disc drive, amplify it, feed it through a suitable A...
by Coeus
Wed Oct 30, 2019 7:20 pm
Forum: off-topic
Topic: LOLPRICE
Replies: 2955
Views: 285879

Re: LOLPRICE

Is it worth much that? Cos i've got the same record somewhere Exactly the same? There's more to it than which piece of music is on the record. Like anything it's about rarity so if you have a copy where there's a mistake on the label where only a few leaked out before it was corrected then that's m...
by Coeus
Mon Oct 28, 2019 9:24 pm
Forum: software & utilities for the pc, mac or unix
Topic: Acorn files on a PC/Mac, attributes and transfer software
Replies: 4
Views: 269

Re: Acorn files on a PC/Mac, attributes and transfer software

They've been around since forever, probably the late 1980s. Thanks, Jonathan. So to parse the first bit in C is easy enough. void parse_inf(const char *fn) { unsigned load = 0, exec = 0; char name[13]; size_t len = strlen(fn)+5; char *inf = alloca(len); snprintf(inf, len, "%s.inf", fn); FILE *fp = ...