Search found 1423 matches

by Coeus
Wed Apr 01, 2020 7:37 pm
Forum: off-topic
Topic: Which retro calculator is best?
Replies: 11
Views: 299

Re: Which retro calculator is best?

Edit: I've never heard of AQA before, but they say: "We set and mark the papers for over half of all GCSEs and A-levels taken every year" That may be so but those topics are nothing like anything I remember from O-level maths so it would be surprising if they had crept in at less than A-Level. I do...
by Coeus
Tue Mar 31, 2020 3:31 pm
Forum: off-topic
Topic: Which retro calculator is best?
Replies: 11
Views: 299

Re: Which retro calculator is best?

I am not sure I can say which was the best. I do remember that at the time I was talking to my parents about a scientific calculator for school, as well as the prospect of needing the transcendental functions, there was the issue that scientific calculators obeyed operator precedence and many simple...
by Coeus
Fri Mar 20, 2020 8:31 pm
Forum: off-topic
Topic: Licence advice....
Replies: 20
Views: 811

Re: Licence advice....

There's an interesting philosophical discussion at https://mjg59.dreamwidth.org/54709.html
by Coeus
Wed Mar 18, 2020 3:38 pm
Forum: emulators
Topic: B-Em
Replies: 401
Views: 37487

Re: B-Em

Aha, that was it! I got confused by the b-em.cfg being picked up in different places by the Linux and windows versions! Thanks for the pointer In both cases something that is classed as a 'config' file should be saved and reloaded from a user-specific directory like any other piece of installed sof...
by Coeus
Wed Mar 18, 2020 2:02 pm
Forum: emulators
Topic: B-Em
Replies: 401
Views: 37487

Re: B-Em

Is there a reason why EDIT doesn't work in the Master 128 modes on b-em (v-48e1203 - also on my hacked versions). It works for me on the current master, after your recent pull request. The ROMs memu shows what the hardware emulation thinks is in those ROM sockets but what does *ROMS think? Are any ...
by Coeus
Wed Mar 18, 2020 1:59 pm
Forum: off-topic
Topic: Licence advice....
Replies: 20
Views: 811

Re: Licence advice....

It's also worth mentioning that the author, or more strictly the copyright holder, is free to offer the product under different licenses to different parties. It could be CC-BY-NC to most people, but you could cut a deal to a particular outfit to allow them to manufacture under license, with whatev...
by Coeus
Wed Mar 18, 2020 1:48 pm
Forum: off-topic
Topic: Regex for UK Telephone Numbers
Replies: 19
Views: 574

Re: Regex for UK Telephone Numbers

I'm pretty sure I'm not dealing with any old area codes before the extra 1 was introduced though. That would likely be impossible to regex. Some cities had special short codes that allowed nearby but not quite local towns to be dialled at local rates. From Glasgow, "32" would get you East Kilbride ...
by Coeus
Tue Mar 17, 2020 8:51 pm
Forum: off-topic
Topic: Licence advice....
Replies: 20
Views: 811

Re: Licence advice....

AFAICT, none of the OpenSource licenses prevent commercial use; they just add additional restrictions (eg the GPL redisitribution clause) on use. My memory of the GPL is mostly from a talk by Richard Stallman rather than reading every detail so correct me if I am wrong but my understanding is that ...
by Coeus
Fri Jan 24, 2020 8:01 pm
Forum: hardware
Topic: Difference between perspex panels?
Replies: 6
Views: 323

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: 48
Views: 2357

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: 48
Views: 2357

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: 48
Views: 2357

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: 527

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: 386

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: 386

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: 1605

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: 48
Views: 2357

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: 606

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: 491

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: 491

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: 491

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: 898

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: 951

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: 951

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: 951

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: 248

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: 63
Views: 2017

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: 888

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: 1135

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: 650

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...