Search found 914 matches

by Richard Russell
Tue Oct 15, 2019 4:24 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

dhg2 wrote:
Tue Oct 15, 2019 4:10 pm
I notice that if you try to draw text at the location of the graphics cursor (with VDU 5 and then PRINT), and if the current graphics colour is black, no text is drawn.
How very strange. Here's what BBC BASIC for SDL 2.0 produces:

blacktextwhitesurround.png
by Richard Russell
Mon Oct 14, 2019 1:39 pm
Forum: software: other
Topic: Calculating digits of Pi in Basic
Replies: 33
Views: 434

Re: Calculating digits of Pi in Basic

geraldholdsworth wrote:
Mon Oct 14, 2019 12:39 pm
I noticed that the first digit always seems to '0', and the decimal point is missing.
The subject line does say 'Calculating digits of Pi', not 'Calculating Pi', so omitting the decimal point and adding any number of leading zeroes is entirely consistent with that.
by Richard Russell
Mon Oct 14, 2019 11:45 am
Forum: software: other
Topic: Calculating digits of Pi in Basic
Replies: 33
Views: 434

Re: Calculating digits of Pi in Basic

BTW, my switch to indirection rather than array mightn't have helped at all As I am increasingly wanting my BBC BASIC programs to run on 64-bit platforms I am trying to change my mind-set away from thinking of indirection as a way of saving time and space to being unhelpful from a compatibility sta...
by Richard Russell
Mon Oct 14, 2019 11:03 am
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

the only variables available to hold addresses/pointers are signed integers. Sorry, that was a silly thing to say because of course BBC BASIC's floating point variables can hold positive 32-bit integers over the entire &00000000 to &FFFFFFFF range. But it isn't usual to use floating-point variables...
by Richard Russell
Mon Oct 14, 2019 9:45 am
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

Conversely, if addresses are signed at 32-bits then you can end up with the odd situation where HIMEM < PAGE. That can't be right either. But that's always been true in BBC BASIC, in principle, since the only variables available to hold addresses/pointers are signed integers. Theoretically even Aco...
by Richard Russell
Mon Oct 14, 2019 9:21 am
Forum: software: other
Topic: Calculating digits of Pi in Basic
Replies: 33
Views: 434

Re: Calculating digits of Pi in Basic

BigEd wrote:
Mon Oct 14, 2019 8:30 am
But wait: the OS supports a printer, and control-B enables it, so how about capturing that output into a text area?
Can't you currently 'print' to a PDF and copy-and-paste the text from that?
by Richard Russell
Mon Oct 14, 2019 9:18 am
Forum: software: other
Topic: Calculating digits of Pi in Basic
Replies: 33
Views: 434

Re: Calculating digits of Pi in Basic

scruss wrote:
Mon Oct 14, 2019 12:52 am
Couldn't get it to run at all in Matrix Brandy on the same machine.
It runs fine in BBC BASIC for Windows and in BBC BASIC for SDL 2.0 (in the latter case on a 32-bit platform; the modification to use indirection rather than an array has of course broken 64-bit compatibility).
by Richard Russell
Sun Oct 13, 2019 8:06 pm
Forum: general
Topic: Remarkable videos recently posted on Youtube
Replies: 276
Views: 31654

Re: Remarkable videos recently posted on Youtube

Elminster wrote:
Sun Oct 13, 2019 5:41 pm
I am not sure there was a huge consensus though.
The only other name they came up with was David Allen, but they (rightly, I think) concluded that he would have been unlikely to attend such a 'technical' meeting.
by Richard Russell
Sun Oct 13, 2019 5:37 pm
Forum: general
Topic: Remarkable videos recently posted on Youtube
Replies: 276
Views: 31654

Re: Remarkable videos recently posted on Youtube

"Micro Men - 10th Anniversary - With Chris Curry, Steve Furber and Hermann Hauser". https://www.youtube.com/watch?v=yaonVYOTSsk So the historical record doesn't become even more muddled, can I confirm that I wasn't one of the representatives from the BBC who visited Acorn for that original demo (th...
by Richard Russell
Sun Oct 13, 2019 3:55 pm
Forum: software: other
Topic: *GRAPHICS command
Replies: 3
Views: 230

Re: *GRAPHICS command

Is it tokenised, so is it Acorn format or Russell format? It arrived with me as 'Russell' format but they had already tried running it in, and may have saved it from, BB4W. The program *LOADs some machine code (apparently) to access a serial port, which would help with CPU identification, but they ...
by Richard Russell
Sun Oct 13, 2019 10:03 am
Forum: software: other
Topic: *GRAPHICS command
Replies: 3
Views: 230

*GRAPHICS command

Somebody has sent me a BBC BASIC program and asked me to identify what machine it was originally written for! The main things which may provide a clue are the statements HIMEM=&FCFF (which I am assuming rules out a BBC Micro) and *GRAPHICS, which I don't recognise. Any ideas?
by Richard Russell
Sat Oct 12, 2019 9:20 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

In which case, the next best thing would be for the 64-bit interpreter to throw an error if you try to assign a pointer to a 32-bit variable while there is more than 4GB allocated BBC BASIC for SDL 2.0 reports the usual 'Number too big' error if you try to assign a value outside the range -2^31 to ...
by Richard Russell
Sat Oct 12, 2019 9:09 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

So you ought to be able safely to use 32-bit pointers as long as (1) you limit your memory usage, and (2) all addresses that BASIC programs wind up seeing are relative and not absolute. Which is basically what Matrix Brandy used to do. But, as discussed here before, doing that is not compatible wit...
by Richard Russell
Sat Oct 12, 2019 12:05 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

If I read that right, a program written to run on BBCSDL on a 32-bit platform can then fail on a 64-bit platform. That can't be right.... can it? If you want a program to run on both 32-bit and 64-bit platforms you must use 64-bit variables for addresses/pointers; they are capable of holding either...
by Richard Russell
Sat Oct 12, 2019 9:19 am
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

Other recent updates include ensuring that PAGE, HIMEM and friends all return positive numbers on 32-bit hardware Is that really what you mean? Suppose that, on a 32-bit platform, HIMEM is &C0000000 (not possible in Windows, normally, but definitely possible in 32-bit Linux or Android). Since it's ...
by Richard Russell
Fri Oct 11, 2019 10:30 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

I've just noticed today that one of my old programs from last year causes an 'Address exception' error on the latest github version of matrix brandy. For that program to run successfully in BBCSDL (on a 64-bit platform) it would be necessary to change pic% to pic%% , p% to p%% and P% to P%% (becaus...
by Richard Russell
Fri Sep 20, 2019 8:12 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released

Bug fix for VAL - it should ONLY handle decimal numbers (not hex or binary) I think that's unfortunate. That was a pretty nice feature that I used quite a bit. I strongly disagree. It was a bug, and as such broke some of my programs (those that rely on VAL being guaranteed to return zero for any st...
by Richard Russell
Tue Sep 10, 2019 5:55 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

I draw the line at buying a Mac. :wink: I sympathise, but I had no choice in order to create the MacOS and iOS editions of BBCSDL (I bought a Mac Mini so that I could at least share my monitor, mouse and keyboard using a KVM switch). There's also Android to add to the list of platforms I would need...
by Richard Russell
Tue Sep 10, 2019 5:29 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

I just report the error, then siglongjmp() to the error handler (from ON ERROR) or back to the immediate mode loop. Yes, I understand how errors are handled (I do the same), I meant how do you intercept the segfault? Are you using 'sigaction()'? It's this at the man page that scares me: " Applicati...
by Richard Russell
Tue Sep 10, 2019 4:05 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

any illegal read or write will raise Address exception but won't crash Brandy itself. I have mixed feelings about the desirability of trapping segfaults. Raymond Chen, the Microsoft guru and blogger, advises that it's best to let the application crash (I appreciate that you probably aren't using Is...
by Richard Russell
Tue Sep 10, 2019 1:21 pm
Forum: off-topic
Topic: Capturing interlaced / 50Hz video
Replies: 37
Views: 921

Re: Capturing interlaced / 50Hz video

I see another fpga project coming on - a scan doubler of some sort - any recommendations for video DAC's? If you can find a capture device that will save the 576i 'properly' (i.e. without attempting to deinterlace or otherwise mangling the video) you can do the conversion to 576p50 downstream, eith...
by Richard Russell
Mon Sep 09, 2019 11:37 am
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

To reiterate, I was the one who merged the pull request, nobody else has access to do that on my branch. So, do not worry about anybody being able to do something unexpected to BBCSDL. Fair enough. I am somewhat obsessive about regressions, for example before issuing a new version of BBCSDL I run '...
by Richard Russell
Sun Sep 08, 2019 9:24 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

A recent merge from @jgharston has removed the offsetting used for Brandy's memory space. I'm surprised that can happen, especially without you knowing. Is it because you are sharing StarDot's github account that he is able to make changes? I'm hoping nothing similar can happen to BBC BASIC for SDL...
by Richard Russell
Fri Sep 06, 2019 2:59 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

dhg2 wrote:
Fri Sep 06, 2019 12:51 pm
Sorry, I forgot to mention that in the case of bb4w, I changed that procedure
Grr. You really don't want to get me started again on those GCOL extensions that don't even have VDU equivalents! :evil:
by Richard Russell
Fri Sep 06, 2019 12:46 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC VI for Linux with SDL: V1.22.1 released
Replies: 782
Views: 39672

Re: Matrix Brandy BASIC VI for Linux with SDL: V1.22.0 released

it behaves correctly on ... Richard Russell's BB4W. I don't understand how it can have done, since it includes this code: DEF PROCgcol(c%) GCOL (c%AND&FF0000)>>16, (c%AND&00FF00)>>8, c%AND&FF ENDPROC which has GCOL followed by three parameters. I know about the one-parameter and two-parameter varia...
by Richard Russell
Wed Sep 04, 2019 3:02 pm
Forum: off-topic
Topic: Capturing interlaced / 50Hz video
Replies: 37
Views: 921

Re: Capturing interlaced / 50Hz video

I was under the impression that some de-interlacers used motion compensation (where it tries to guess the trajectory of moving objects and compensate for this)...something I really don't want. There are indeed motion-compensated deinterlacers, but as you say these aren't relevant to you. It's proba...
by Richard Russell
Wed Sep 04, 2019 1:16 pm
Forum: off-topic
Topic: Capturing interlaced / 50Hz video
Replies: 37
Views: 921

Re: Capturing interlaced / 50Hz video

I suspect the de-interlace may make my problems worse i.e. does it shuggle lines horizontally to de-interlace to a 25p frame? A deinterlacer shouldn't be doing anything "horizontally"! All good deinterlacers are vertical-temporal filters of some kind; the beauty of Martin Weston's filter is that it...
by Richard Russell
Wed Sep 04, 2019 1:04 pm
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 version 1.06a released
Replies: 3
Views: 289

Re: BBC BASIC for SDL 2.0 version 1.06a released

I was going to ask for some screenshots... I generally work on the basis that virtually anybody can run BBC BASIC for SDL 2.0 , since it is available for so many platforms (including Android and iOS), so if you want to see it in action you can try it for yourself. Perhaps this forum is the one plac...
by Richard Russell
Wed Sep 04, 2019 9:54 am
Forum: software & utilities for the pc, mac or unix
Topic: BBC BASIC for SDL 2.0 version 1.06a released
Replies: 3
Views: 289

Re: BBC BASIC for SDL 2.0 version 1.06a released

Here's what the supplied example program aagfxdem.bbc produces, on all the supported platforms:

Image
by Richard Russell
Wed Sep 04, 2019 9:46 am
Forum: off-topic
Topic: Capturing interlaced / 50Hz video
Replies: 37
Views: 921

Re: Capturing interlaced / 50Hz video

I have interlace turned off usually on the beeb so I guess that is really 288/50p that I want to capture? With interlace turned off it's a non-standard video format so possibly a capture card won't lock to it at all, it will depend on how tolerant it is. I would recommend leaving interlace on and t...