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by Coeus
Sun Nov 29, 2020 9:43 pm
Forum: 8-bit acorn software: other
Topic: Why was BBC BASIC so fast?
Replies: 196
Views: 7050

Re: Why was BBC BASIC so fast?

Yes. I posted a long and detailed account of my experiences with the 8271 in the thread discussing its reverse engineering. But I realised it was hopelessly off-topic (as it is here) and would likely get me banned from the forum, so I deleted it. That's a pity. I did read it and find it interesting...
by Coeus
Sun Nov 29, 2020 9:39 pm
Forum: scanning of books, magazines, ads and letters
Topic: BCPL for the BBC Microcomputer [Remastered PDF]
Replies: 11
Views: 156

Re: BCPL for the BBC Microcomputer [Remastered PDF]

danielj wrote:
Sun Nov 29, 2020 6:09 pm
I've just given dv8 a link to the TIFFs for the calc package manual. They do need some bodgery to make them useful!
Brilliant - we've had the others in some form for a while, though dv8's remastered version is a big improvement, but this had been missing until now.
by Coeus
Sun Nov 29, 2020 9:37 pm
Forum: scanning of books, magazines, ads and letters
Topic: BCPL for the BBC Microcomputer [Remastered PDF]
Replies: 11
Views: 156

Re: BCPL for the BBC Microcomputer [Remastered PDF]

Attached are remastered PDFs of the books BCPL for the BBC Microcomputer and BCPL Stand Alone Generator on the BBC Microcomputer by Chris Jobson and John Richards. Another wonderful recreation - thanks for your effort across the whole series. That summary of the calculations package is also the bes...
by Coeus
Fri Nov 27, 2020 4:29 pm
Forum: 8-bit acorn hardware
Topic: Cassette colour cables
Replies: 4
Views: 170

Re: Cassette colour cables

The motor control and the signal lines (in/out) are independent so each may work or not work. So, if you can't get the motor control to work then leave it for now, leave the motor control jack plug unplugged and see if you can get the BBC micro to load from tape with the tape manually controlled. If...
by Coeus
Fri Nov 27, 2020 1:45 pm
Forum: 8-bit acorn software: other
Topic: Why was BBC BASIC so fast?
Replies: 196
Views: 7050

Re: Why was BBC BASIC so fast?

Absolutely! A system without interrupts isn't a fair comparison. So, assuming you could adapt it to a XZ81, would running in FAST mode rather than display and compute (SLOW) mode be cheating? Different systems do have very different levels of interrupt activity. I suspect many CP/M machines would h...
by Coeus
Wed Nov 25, 2020 9:37 pm
Forum: 8-bit acorn software: other
Topic: Why was BBC BASIC so fast?
Replies: 196
Views: 7050

Re: Why was BBC BASIC so fast?

It was in REM statements:
clocksp.png
clocksp.png (2.85 KiB) Viewed 288 times
by Coeus
Wed Nov 25, 2020 9:32 pm
Forum: 8-bit acorn software: other
Topic: Why was BBC BASIC so fast?
Replies: 196
Views: 7050

Re: Why was BBC BASIC so fast?

Oh. I tested it in BeebEm and assumed that it would be representative of a Model B (the changes I made shouldn't have had any effect when running in Sophie's 6502 BASIC, and the 'later tests' weren't touched): That image looks like CLOCKSP run with interrupts enabled. To hit the 2Mhz spot on you ha...
by Coeus
Wed Nov 25, 2020 9:17 pm
Forum: general
Topic: BBC B screen position
Replies: 10
Views: 334

Re: BBC B screen size

This sounds related to over-scan, or to put it another way, although the TV standard at the time the BBC micro was produced was described as 625 line, the way TV sets were typically set up some of these lines were not displayed on the screen. Possibly the difference is more than many people remember...
by Coeus
Fri Nov 20, 2020 12:22 pm
Forum: introduce yourself
Topic: Hello - BBC B Newbie
Replies: 17
Views: 377

Re: Hello - BBC B Newbie

Becky wrote:
Fri Nov 20, 2020 9:11 am
"Maybe I should look for a second machine to keep as a spare in case something goes wrong"
Indeed someone asked "Master of BBC B?" a little while ago and got the rely "Well both of course?" or something like that.
by Coeus
Fri Nov 20, 2020 12:14 pm
Forum: 8-bit acorn hardware
Topic: 8271 floppy controller reverse engineer journey write-up
Replies: 23
Views: 1076

Re: 8271 floppy controller reverse engineer journey write-up

I am sure it can be done, but how? (In some ways, this reverse engineering victory has made it harder!) That depends on how much of a purist you want to be and what the end goal is. Is the intention is to be able to run software, including copy-protected software, written for the BBC micro? There i...
by Coeus
Thu Nov 19, 2020 9:27 pm
Forum: 8-bit acorn emulators
Topic: Intercepting the sound output
Replies: 13
Views: 1084

Re: Intercepting the sound output

It's a great idea. It turns out not to be quite so simple as I had first thought, though. Intercepting at the OSWORD level means the emulator then has to do things the BBC OS would have done previously such as synchronising the start of notes that form a chord. That's doable, of course, but I find i...
by Coeus
Thu Nov 19, 2020 9:24 pm
Forum: software & utilities for the pc, mac or unix
Topic: Beebasm: Macros with string arguments
Replies: 6
Views: 221

Re: Beebasm: Macros with string arguments

Sorry, this won't work in BeebAsm. String variables aren't supported at all, be they regular symbols or macro parameters. String literals are really no more than a special case hack for whichever keywords take them (EQUS, INCLUDE, etc) Thanks for getting back to me. I am not sure how many other ass...
by Coeus
Thu Nov 19, 2020 9:21 pm
Forum: 8-bit acorn software: other
Topic: BBC Master - Calendar shows 1920 not 2020
Replies: 7
Views: 223

Re: BBC Master - Calendar shows 1920 not 2020

BeebMaster wrote:
Thu Nov 19, 2020 8:42 pm

Code: Select all

 1550T$=TIME$:IFMID$(T$,12,2)="19" T$=LEFT$(T$,11)+"20"+MID$(T$,14)
The patch to the OS is only doing in assembler what you're doing in BASIC.
by Coeus
Thu Nov 19, 2020 6:26 pm
Forum: introduce yourself
Topic: Hello - BBC B Newbie
Replies: 17
Views: 377

Re: Hello - BBC B Newbie

Welcome to the forum, Becky. Yes, the industrial design of the BBC B was solid - imagine how things would have been in the classroom with the wobbly ZX81 RAM pack. Perhaps not so much so as the RM 380Z that preceded it as a school computer but then that cost several thousand when released. The indus...
by Coeus
Thu Nov 19, 2020 5:44 pm
Forum: general
Topic: Today I received.....
Replies: 6056
Views: 640960

Re: Today I received.....

I have had things arrive slowly with Royal Mail, up to a week after posting, even 1st class items. So fingers crossed your stuff turns up in the end. People talk about how efficient the various delivery firms are but I think it can depend very heavily on the people involved in the last leg of the j...
by Coeus
Wed Nov 18, 2020 7:30 pm
Forum: 8-bit acorn software: other
Topic: BBC Master - Calendar shows 1920 not 2020
Replies: 7
Views: 223

Re: BBC Master - Calendar shows 1920 not 2020

The fundamental issue that the real time clock chip only stores the year to two digits so software has to make some assumption about which century. We can change the assumption it makes to make more sense post 2000. If you want to leave the original OS ROM as-is then Sprow's Y2K fix is ideal. On the...
by Coeus
Wed Nov 18, 2020 7:20 pm
Forum: 8-bit acorn hardware
Topic: Loose ROM sockets
Replies: 12
Views: 276

Re: Loose ROM sockets

I should take the board out and inspect it under my desk magnifier in the workshop in my office and see if I can spot any dodgy connections. I probably won't do that unless the issues become more pronounced because I am loath to bust things / make it worse. Pulling the power cables off the spade co...
by Coeus
Wed Nov 18, 2020 3:46 pm
Forum: software & utilities for the pc, mac or unix
Topic: Beebasm: Macros with string arguments
Replies: 6
Views: 221

Re: Beebasm: Macros with string arguments

How about no quotes at all? Not sure if this works but seems plausible: Thanks, Bobbi. It looks like I have made a copy/paste error. Your version is the one I intended to post as the first syntax, i.e. the two syntaxes I tried were: Quotes around the string in the call and not in the definition. Qu...
by Coeus
Wed Nov 18, 2020 2:39 am
Forum: software & utilities for the pc, mac or unix
Topic: Beebasm: Macros with string arguments
Replies: 6
Views: 221

Beebasm: Macros with string arguments

I am trying to use a string as an argument to a macro in beebasm but don't seem to be able to find a syntax that works. For example, the obvious: MACRO err1 code,msg JSR cpyerr1 EQUB code EQUS "msg" EQUB &00 ENDMACRO .L82e8 err1 &c9,"Disc protected" gives "error: Bad expression." and moving the quot...
by Coeus
Mon Nov 16, 2020 12:03 pm
Forum: general
Topic: DOS vs UNIX Line Endings
Replies: 21
Views: 472

Re: DOS vs UNIX Line Endings

I'm not sure that it "generates" CR, at least not on the modern platforms I mostly deal with. Typically pressing the Enter key results in a 'key down' event with the key being identified by a symbolic constant (e.g. VK_ENTER) that could in principle be anything. When I receive that event I do write...
by Coeus
Mon Nov 16, 2020 10:20 am
Forum: general
Topic: DOS vs UNIX Line Endings
Replies: 21
Views: 472

Re: DOS vs UNIX Line Endings

Really, both should be used, as LF and CR are different things... But of course, that used up more valuable memory, so most of the time, instead only one control code was used. So that's an output-centric view of a text file, i.e. something that can be copied byte for byte to an output device such ...
by Coeus
Sun Nov 15, 2020 7:42 pm
Forum: 8-bit acorn software: other
Topic: MMFS Version 2
Replies: 368
Views: 2687

Re: SD card without the MMB file (aka MMFS2)

On the point about *DOP and read-only discs, does MMFS2 honour the FAT R/O attribute, i.e. if the image file is marked R/O as seen by DOS/Windows does MMFS2 treat that as a write-protected disc?
by Coeus
Sat Nov 14, 2020 8:10 pm
Forum: off-topic
Topic: Relays
Replies: 4
Views: 157

Re: Relays

Connecting the scope was a fail. Upon connecting the ground side of the probe it tripped the RCCB. That seems a little odd as it seems to suggest two things must be true: The ground side of the scope's V amplifier for that channel must be connected to protective earth. There must be no isolation bet...
by Coeus
Sat Nov 14, 2020 7:45 pm
Forum: off-topic
Topic: Relays
Replies: 4
Views: 157

Re: Relays

Alternatively, the controller may have an economiser circuit which reduces the voltage to the relay once it has operated. This is done to save power, reduce the heat from the coil, and so that a lower cost power supply system can be used. However, these economiser circuits are not very common. Than...
by Coeus
Sat Nov 14, 2020 7:10 pm
Forum: general
Topic: DOS vs UNIX Line Endings
Replies: 21
Views: 472

Re: DOS vs UNIX Line Endings

Kate claims to have line ending auto detection , but I've never used it. Gedit (3.36.2, at least) silently keeps whatever line endings it was fed, offering to change under "Save As". Emacs does too, but you probably don't want to go there. Geany (GTK-based, light IDE) also deals with different line...
by Coeus
Sat Nov 14, 2020 7:01 pm
Forum: general
Topic: DOS vs UNIX Line Endings
Replies: 21
Views: 472

Re: DOS vs UNIX Line Endings

None of these utilities add the expected Ctrl-Z at end of file that CP/M needs, but you probably don't need that. See https://github.com/SteveFosdick/Utils The utilities txt2bbc, txt2cpm, and txt2dos all write files with the corresponding line ending and, in the case of txt2cpm, with the ^Z at the ...
by Coeus
Sat Nov 14, 2020 12:52 pm
Forum: off-topic
Topic: Relays
Replies: 4
Views: 157

Relays

I am trying to diagnose an intermittent fault with our dishwasher. When it doesn't work, the fault code displayed means "water not heating". The heater is controlled by a relay and from what I can tell the controller is able to monitor the switched output of the relay to determine if the contacts ha...
by Coeus
Wed Nov 11, 2020 11:46 pm
Forum: 8-bit acorn software: other
Topic: MMFS Version 2
Replies: 368
Views: 2687

Re: SD card without the MMB file (aka MMFS2)

You can make a DSD by concatenating two SSD files (not on the Beeb, on Linux or Windows or Mac ...). That will give you a file the correct size. As in: cat side1.ssd side21.ssd > double.dsd If MMFS2 uses that format then it is a bit odd. There are some DSDs files out there like that with one side f...
by Coeus
Sat Nov 07, 2020 6:37 pm
Forum: 8-bit acorn software: other
Topic: MMFS Version 2
Replies: 368
Views: 2687

Re: MMFS Version 2

Why is this? The Directories don't ever have a suffix so the *DDIR function should neither look for it not attempt to add a suffix. At a guess the code uses a common subroutine to parse a name whether it is a file name or a directory name. I have to say that I don't like this. If you have to rememb...
by Coeus
Fri Nov 06, 2020 1:26 pm
Forum: 8-bit acorn emulators
Topic: Creating Disk Images on a BBC Master
Replies: 7
Views: 1245

Re: Creating Disk Images on a BBC Master

It may help to say a bit more about what you would want to do with the image of a DFS disc once it is in a file on an ADFS disc. It is worth noting that the SSD and DSD image formats cannot cope with most protected discs because they only store the data in the sectors, not the metadata about the sec...

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