Search found 3879 matches

by BigEd
Fri Feb 26, 2021 3:07 pm
Forum: past weeknight 'general' acorn sessions
Topic: Weekday 'Virtual' General session #17, Tuesday 16th February 2021, 7pm - 10pm (GMT)
Replies: 10
Views: 117

Re: Weekday 'Virtual' General session #17, Tuesday 16th February 2021, 7pm - 10pm (GMT)

Kecske Bak wrote:
Fri Feb 26, 2021 1:40 pm
I'd be happy to attend the 2nd March meeting if you'd like me to come.
sounds good to me - try over here:
viewtopic.php?f=25&t=21795
by BigEd
Fri Feb 26, 2021 11:49 am
Forum: 8-bit acorn hardware
Topic: Forty years ago...
Replies: 77
Views: 2379

Re: Forty years ago...

Thanks Richard. Looks like the User Port was a bonus. I like the idea of the 'central unit' being what we'd now just call the Beeb. The 74 keys turned out just right, but the two-key reset was evidently found not to be necessary (OLD to the rescue).
by BigEd
Thu Feb 25, 2021 8:06 pm
Forum: general
Topic: Remarkable videos recently posted on Youtube
Replies: 388
Views: 62916

Re: Remarkable videos recently posted on Youtube

oh Tim Hunkin - that'll be excellent!
by BigEd
Wed Feb 24, 2021 8:51 am
Forum: general
Topic: Beeb Spotting
Replies: 107
Views: 15721

Re: Beeb Spotting

Just adding a couple more old photos and linking back to the other thread . The text of the exhibit's description reads as follows...: ... The UMI sequencer was developed by musician Lynton Naiff, and was sold by the London Rock Shop. Vince Clarke (Erasure, Depeche Mode) is one of the most well-kno...
by BigEd
Tue Feb 23, 2021 8:14 pm
Forum: programming
Topic: Wish: MAVIS computer recreation in Mode 7
Replies: 55
Views: 1295

Re: Wish: MAVIS computer recreation in Mode 7

Just trying to collect some comparisons. First, comparison of two (or three!) tape systems. Philips' Mini Digital Cassette Recorder aka Mini-DCR uses Manchester encoding with a bit cell time of 167 microseconds. An OEM unit offers a 13-pin 14-position AMP connector. The cassette contains 35 meters o...
by BigEd
Mon Feb 22, 2021 9:28 pm
Forum: new projects in development: games
Topic: Making reasonable progress with a Sudoku solver
Replies: 98
Views: 12792

Re: Making reasonable progress with a Sudoku solver

I know this particular development is done, but just for interest: I ran the solver on a few different permutations of the same problem, and got a large variation in elapsed times (80, 40, 9 seconds, more or less.)


See photos:
by BigEd
Mon Feb 22, 2021 9:13 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

No, no wind up, just my own inattention and, I suppose, over-confidence. My apologies for missing the pointer.

(One must use the context menu, in the file browser: a long press on a touch device, a two-finger-click on a Mac touchpad, or a right-click on a mouse.)
by BigEd
Mon Feb 22, 2021 8:26 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

I think I haven't seen that documentation! Bear in mind, although I was aware of your browser edition from an early stage, most recently I clicked on the links in the head post of this thread. Also, there's no doubt an effect that I didn't know I was missing any information. Edit: maybe link to the ...
by BigEd
Mon Feb 22, 2021 7:11 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

Ah, context menu - I didn't think of that, didn't expect one. Yes, that works - thanks!
by BigEd
Mon Feb 22, 2021 6:47 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

Hmm, I feel I must be missing something. If I invoke touchide, I get the file browser. If in the file browser I click on sudoku.bbc, it loads and runs. I have not found a way to edit the source, other than RENUMBER and inputting new or replacement lines. That's fine, if it's so, but it sounds from w...
by BigEd
Mon Feb 22, 2021 5:19 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

Ah - I see that RENUMBER would then let me change a line. (As far as I can tell, line editing is all I have, in the browser.)

But I also see that you've removed the timeout already - thanks Richard!
by BigEd
Mon Feb 22, 2021 4:54 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

Ah, a simple fix - hurrah! (I don't see how to modify the Basic program in the browser version, although I can LOAD and LIST.)
by BigEd
Mon Feb 22, 2021 4:25 pm
Forum: programming
Topic: Wish: MAVIS computer recreation in Mode 7
Replies: 55
Views: 1295

Re: Wish: MAVIS computer recreation in Mode 7

My best guess from what we've seen so far is that the tapes Dominic has, which are from a MAVIS system, are the right physical form factor for the HP 82161A Digital Cassette Drive, and that the MAVIS and HP mechanisms will be the same. But it wasn't an HP unit that was used by MAVIS, and we don't kn...
by BigEd
Mon Feb 22, 2021 2:55 pm
Forum: modern implementations of classic programming languages
Topic: Direct Links to In-Browser Demos
Replies: 28
Views: 429

Re: Direct Links to In-Browser Demos

Richard, not sure where to note this, but your posted sudoku demo finds the T.HARD1 puzzle "Impossible" - unless perhaps I've done something wrong. Edit: or perhaps the program tries some set of reasoning and isn't able to resolve the answer? In which case it would have found the puzzle &q...
by BigEd
Mon Feb 22, 2021 2:10 pm
Forum: off-topic
Topic: Electric Cars - A general discussion platform
Replies: 57
Views: 1106

Re: Electric Cars - A general discussion platform

For myself, 2020 has shown that I barely need to own a car, so I'm convinced now that my present car should be the last one I own. I can still hire a car when necessary, and a hire car gets more use than a private car, so that's a win for everyone. (Of course, circumstances differ! I'm not suggestin...
by BigEd
Mon Feb 22, 2021 12:15 pm
Forum: 8-bit acorn software: other
Topic: ABC compiles Basic V to 6502? [ABC65]
Replies: 29
Views: 1922

Re: ABC compiles Basic V to 6502? [ABC65]

Yes, seems likely. But if it's a dim enough compiler (sorry Paul) the source and the object code will bear a strong structural relationship. If it's the case that ABC65 was never released, perhaps we'll come across a pre-release or a prototype - and who knows, maybe some source on that floppy!
by BigEd
Mon Feb 22, 2021 11:00 am
Forum: 8-bit acorn software: other
Topic: ABC compiles Basic V to 6502? [ABC65]
Replies: 29
Views: 1922

Re: ABC compiles Basic V to 6502? [ABC65]

Good catch lurkio: ABC is (orginally) written in Basic, which is why it's handy for it to compile itself so it can run faster. I suppose this means that the retail version looks like ARM code - the Basic source won't be shipped.
by BigEd
Mon Feb 22, 2021 10:22 am
Forum: 8-bit acorn software: other
Topic: ABC compiles Basic V to 6502? [ABC65]
Replies: 29
Views: 1922

Re: ABC compiles Basic V to 6502? [ABC65]

ABC65 is software for an Archimedes, so it might be known to the JASPP denizens. Anyhow, good suggestion, I've posted a query at JASPP and also on ROOL.
by BigEd
Mon Feb 22, 2021 10:05 am
Forum: general
Topic: Remarkable videos recently posted on Youtube
Replies: 388
Views: 62916

Re: Remarkable videos recently posted on Youtube

Multiwizard wrote:
Sun Feb 21, 2021 6:14 pm
tricky wrote:
Sun Feb 21, 2021 5:20 pm
Not on youtube yet and probably/hopefully not remarkable, but I and my games should be on Mamemeister's live stream from 6 'til 8 tonight.
https://www.youtube.com/user/mamemeister
Thanks for this... :-D
Nice one tricky!
by BigEd
Sun Feb 21, 2021 12:27 pm
Forum: general
Topic: Remarkable videos recently posted on Youtube
Replies: 388
Views: 62916

Re: Remarkable videos recently posted on Youtube

Yesterday's Click had a section on cardboard computer and the BBC Micro including TNMOC's micro olympics. Watch Out for gratuitous adult content as the presenter kisses a cardboard replica of his beloved micro. Can watch online here: https://www.bbc.co.uk/iplayer/episode/m000smzg/click-clubhouse-co...
by BigEd
Sun Feb 21, 2021 9:25 am
Forum: programming
Topic: Wish: MAVIS computer recreation in Mode 7
Replies: 55
Views: 1295

Re: Wish: MAVIS computer recreation in Mode 7

I can certainly ask!

Meanwhile, see the article on p17 of the HP Journal for May 1983, about the 82161A Digital Cassette Drive:
82161A-data-cassette-timing.png
by BigEd
Sun Feb 21, 2021 9:04 am
Forum: 8-bit acorn hardware
Topic: Forty years ago...
Replies: 77
Views: 2379

Re: Forty years ago...

1024MAK wrote:
Sun Feb 21, 2021 3:22 am
Err, all mainstream DRAM then had a multiplexed address bus.
Yes, I should perhaps have said that MADRAM is a new term to me. Must have been in use only briefly, perhaps in a world where people were very used to SRAM with non-multiplexed address busses.
by BigEd
Sun Feb 21, 2021 9:02 am
Forum: programming
Topic: 6502 BASIC Compiler
Replies: 29
Views: 4579

Re: 6502 BASIC Compiler

(We should probably link back - or forwards - to the ABC65 thread.)
by BigEd
Sun Feb 21, 2021 8:54 am
Forum: 8-bit acorn hardware
Topic: Was there ever a 68000 co-pro for tbe BBC/Master?
Replies: 11
Views: 424

Re: Was there ever a 68000 co-pro for tbe BBC/Master?

Welcome! That's a nice project - built back in the 80s?
by BigEd
Sat Feb 20, 2021 10:33 pm
Forum: 8-bit acorn hardware
Topic: Forty years ago...
Replies: 77
Views: 2379

Re: Forty years ago...

MADRAM is new to me: "MADRAM = multiplexed address bus dynamic RAM" apparently. It seems a possible reading that the Second Processor was to be an optional second board within the same case: The Tube circuitry allows a very fast byte parallel interface to the other circuit board with the l...
by BigEd
Sat Feb 20, 2021 6:40 pm
Forum: programming
Topic: Wish: MAVIS computer recreation in Mode 7
Replies: 55
Views: 1295

Re: Wish: MAVIS computer recreation in Mode 7

Oh, good find. Perhaps someone at the HPCC can help with the loan of a drive? There are many hp-41 fans and many completist collectors. They (we!) meet twice a month online. The 82176A Mini Data Cassette was introduced by Hewlett-Packard in 1982 for use in its 82161A mini-cassette tape drive that wa...
by BigEd
Sat Feb 20, 2021 5:55 pm
Forum: programming
Topic: Wish: MAVIS computer recreation in Mode 7
Replies: 55
Views: 1295

Re: Wish: MAVIS computer recreation in Mode 7

I find the spectrogram helpful to distinguish different types of content - you can easily see the headers and data parts of the blocks in a Beeb tape - but I suspect what we have here is more of a pulse modulation than a frequency modulation. The levels are low, but this has the look about it of dat...
by BigEd
Sat Feb 20, 2021 5:48 pm
Forum: 8-bit acorn hardware
Topic: Was there ever a 68000 co-pro for tbe BBC/Master?
Replies: 11
Views: 424

Re: Was there ever a 68000 co-pro for tbe BBC/Master?

Interesting. (Is that a Z80 on the Torch board?) Inside PiTubeDirect there's a model of the host side of the Tube chip, running on the GPU(!) - that's normally the same code for every coprocessor, but for a 3rd party variant which uses a 6522 instead, that might well need revisiting. It's written in...
by BigEd
Sat Feb 20, 2021 5:46 pm
Forum: general
Topic: "Outline specification for the BBC MICROCOMPUTER system"
Replies: 223
Views: 35224

Re: "Outline specification for the BBC MICROCOMPUTER system"

I'm just going to quote this bit too, because again it's a mention of CP/M: PROCESSOR BUS INTERFACE ("TUBE") (Model B only) Un-buffered address, data and control signals are available on a 40-way connector to provide a high-speed interface to an external language processor (e.g. the Z80 CP...
by BigEd
Sat Feb 20, 2021 1:43 pm
Forum: 8-bit acorn hardware
Topic: Was there ever a 68000 co-pro for tbe BBC/Master?
Replies: 11
Views: 424

Re: Was there ever a 68000 co-pro for tbe BBC/Master?

I think none of the 68k second processors use a Tube chip, so the idea doesn't fit too well to PiTubeDirect (which uses the Tube connection to the host.)

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