BBC releases computer history archive

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chinnyhill10
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Re: BBC releases computer history archive

Post by chinnyhill10 » Sun Jul 01, 2018 10:26 pm

Richard Russell wrote:
Sat Jun 30, 2018 9:44 am

I admit that having worked at BBC R&D for 33 years I have become highly sensitised to video artefacts, and things which I may find disturbing will not necessarily be as apparent to other viewers. But that's not a good reason for the CLPA material to be worse than it needed to be; there have been a number of adverse comments about the quality at 'professional' Facebook groups.

Richard.
I had put down the fact it looked like it had been encoded on a potato down to my poor internet connection and I was viewing it at the lowest possible quality. Are you saying it looks that bad for everyone?

In this day and age there is no reason why it can't be online at full 720x576. Ideally properly de-interlaced and at 50fps.

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Elminster
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Re: BBC releases computer history archive

Post by Elminster » Sun Jul 01, 2018 10:28 pm

chinnyhill10 wrote:
Sun Jul 01, 2018 10:19 pm
hicks wrote:
Thu Jun 28, 2018 12:03 pm
Elminster wrote:
Thu Jun 28, 2018 8:45 am
What were you hoping to achieve?
Nothing in particular, but it'd be nice to be able to legally distribute the ROMs for the Electron/BBC both in terms of FPGA cores and for emulators. Also, never know what comments in source might reveal that can be missed when reviewing disassembled versions. Plain curiosity too :)
Did anyone in the community ask Acorn when they were still a going concern? Seems a bit late in the day now.

Amstrad were approached in the late 90's and they allowed the CPC and Spectrum ROM's to be distributed for free providing the copyright messages were left intact and no charge was made.
I suspect because they split into a number of companies, and those sorts of things get lost between the crack. But someone else may have a better idea.

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Re: BBC releases computer history archive

Post by BigEd » Mon Jul 02, 2018 5:58 am

lcww1 wrote:
Sat Jun 30, 2018 10:36 am
I figured out how to download [many disk images] ... by issuing a URL such as:

https://computer-literacy-project.pilot ... LP0201.ssd

I would trigger the browser to download the .ssd file, which is what it did! By mousing over the links on the CLPA page, one can see the name/number of the .ssd files for each of the programs - however, it does appear that there are more .ssd disc images on the site than are linked to from the CLPA software webpage - this needs further investigation!
Great! Over in this discussion we read:
I downloaded all the floppy images from this archive, and found some interesting (from a historical perspective) documents on some of them.
Lists of computing equipment owned by the BBC in 1987, letters responding to what appears to be viewers who wrote in with questions, that sort of thing.

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Re: BBC releases computer history archive

Post by Coeus » Mon Jul 02, 2018 7:39 am

chinnyhill10 wrote:
Sun Jul 01, 2018 10:26 pm
In this day and age there is no reason why it can't be online at full 720x576. Ideally properly de-interlaced and at 50fps.
Surely that depends on what the source is.

If the original source is either analogue video tape or a digitised copy thereof then after the discussion about de-interlacing it does seem it would be worth doing that before it is streamed/downloaded but I am not sure there is any point in upscaling on the server side - that would just consume more bandwidth while watching without adding any extra quality.

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Re: BBC releases computer history archive

Post by Coeus » Mon Jul 02, 2018 7:45 am

Back to the content of these programs, "The Silicon Factor" was largely about persuding small British manufactering firms to include microprocessor technology in their designs. Does anyone know if that ever happenned to any significant degree?

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Richard Russell
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Re: BBC releases computer history archive

Post by Richard Russell » Mon Jul 02, 2018 8:04 am

chinnyhill10 wrote:
Sun Jul 01, 2018 10:26 pm
I had put down the fact it looked like it had been encoded on a potato down to my poor internet connection and I was viewing it at the lowest possible quality. Are you saying it looks that bad for everyone?
I'm pretty certain everybody gets the same stream; AFAIK the material was only encoded once. This isn't iPlayer or YouTube, but a small project run by a handful of people on a shoestring - as they point out when any criticism is made.

Richard.

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Re: BBC releases computer history archive

Post by Richard Russell » Mon Jul 02, 2018 8:20 am

Coeus wrote:
Mon Jul 02, 2018 7:39 am
Surely that depends on what the source is.
I haven't got to the bottom of why the source material wasn't available from the BBC's archives, and in some cases had to be taken from poor quality copies on VHS and YouTube etc. One message I received from the team referred to these as having been 'place holders' that they expected would be replaced with high quality versions before publication, but never were.
I am not sure there is any point in upscaling on the server side - that would just consume more bandwidth while watching without adding any extra quality.
Nobody is suggesting spatial upscaling, if that's what you mean. But my understanding is that much of the material was processed through a de-interlacer (albeit not the one the BBC normally uses) and in that case it will always be preferable to deinterlace to 50p rather than the 25p that was actually used. I might be more understanding if the reason was to reduce bandwidth, but it seems to have been down to inexperience.

Richard.

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Re: BBC releases computer history archive

Post by tricky » Mon Jul 02, 2018 12:49 pm

Boydie wrote:
Sun Jul 01, 2018 6:51 pm
...
Given that MediaInfo reports that file as being 30fps, whereas all the others seem to be 15fps, could it be that whoever encoded that particular clip forgot to deinterlace it at all?
That explains why the movement looks so weird, but surely it takes more than inexperience to convert to the wrong frame rate (one not related to the original).
Shame really as it is detracting from the experience of watching the ones I missed.

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Re: BBC releases computer history archive

Post by Coeus » Mon Jul 02, 2018 2:09 pm

tricky wrote:
Mon Jul 02, 2018 12:49 pm
That explains why the movement looks so weird, but surely it takes more than inexperience to convert to the wrong frame rate (one not related to the original).
Shame really as it is detracting from the experience of watching the ones I missed.
But isn't 15fps an odd frame rate for UK TV also? If it was simply a case of interface or not it should be 25 fields/sec vs. 50fps.


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Re: BBC releases computer history archive

Post by 1024MAK » Mon Jul 02, 2018 3:08 pm

U.K. System I analogue is 50 fields per second, giving 25 frames per second.
U.S.A. System M analogue is 60 fields per second, giving 30 frames per second.

Mark

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Re: BBC releases computer history archive

Post by chinnyhill10 » Mon Jul 02, 2018 3:14 pm

1024MAK wrote:
Mon Jul 02, 2018 3:08 pm
U.K. System I analogue is 50 fields per second, giving 25 frames per second.
U.S.A. System M analogue is 60 fields per second, giving 30 frames per second.

Mark
Although if you want interlaced movement on a modern progressive display you have to run it at 50fps or 60fps. I have to convert the output of the Beeb and other micros to 50p or you lose frames, especially in games with full 50Hz motion.

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Re: BBC releases computer history archive

Post by 1024MAK » Mon Jul 02, 2018 3:43 pm

chinnyhill10 wrote:
Mon Jul 02, 2018 3:14 pm
1024MAK wrote:
Mon Jul 02, 2018 3:08 pm
U.K. System I analogue is 50 fields per second, giving 25 frames per second.
U.S.A. System M analogue is 60 fields per second, giving 30 frames per second.

Mark
Although if you want interlaced movement on a modern progressive display you have to run it at 50fps or 60fps. I have to convert the output of the Beeb and other micros to 50p or you lose frames, especially in games with full 50Hz motion.
Ahh, but most computers in the 1970s, 1980s and 1990s don't actually produce a proper interlaced output. Instead they just produce a single field, then repeat the same field (and if doing animation, with different picture information). So on a large-ish screen CRT, you can see faint horizontal lines between the lit pixels. This is the lack of scan lines due to the 'missing' field.

Mark
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Re: BBC releases computer history archive

Post by Coeus » Mon Jul 02, 2018 5:49 pm

1024MAK wrote:
Mon Jul 02, 2018 3:43 pm
Ahh, but most computers in the 1970s, 1980s and 1990s don't actually produce a proper interlaced output. Instead they just produce a single field, then repeat the same field (and if doing animation, with different picture information). So on a large-ish screen CRT, you can see faint horizontal lines between the lit pixels. This is the lack of scan lines due to the 'missing' field.
So the BBC micro certainly has half the vertical resolution you'd expect for the number of TV display lines the picture actually occupies but it also has a *TV command to turn interface on/off. I assume that simply introduces a one TV line delay between Vsync and the start of the first pixel on alternate frames? This function is also done by the 6845 via R8 so it could be possible on anything else that uses that.
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Richard Russell
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Re: BBC releases computer history archive

Post by Richard Russell » Mon Jul 02, 2018 6:24 pm

Coeus wrote:
Mon Jul 02, 2018 2:09 pm
But isn't 15fps an odd frame rate for UK TV also?
Some of the recovered material had already been standards-converted to 'NTSC' and apparently couldn't be located in its original PAL format. In that case it's better not to perform another conversion back to 25 fps, which would make the quality even worse, and that no doubt explains the odd frame rate (although surely it's actually 30, not 15?).

Richard.

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Re: BBC releases computer history archive

Post by Richard Russell » Mon Jul 02, 2018 6:28 pm

1024MAK wrote:
Mon Jul 02, 2018 3:43 pm
Ahh, but most computers in the 1970s, 1980s and 1990s don't actually produce a proper interlaced output.
Most, perhaps, but of course it was a requirement from the start that the BBC Micro must be able to generate a 'broadcast compatible' interlaced output so it could be fed as a source into the studio's vision mixer. It's also necessary for 'character rounding' in MODE 7.

Richard.

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Re: BBC releases computer history archive

Post by hicks » Mon Jul 02, 2018 10:33 pm

1024MAK wrote:
Mon Jul 02, 2018 3:43 pm
Ahh, but most computers in the 1970s, 1980s and 1990s don't actually produce a proper interlaced output. Instead they just produce a single field, then repeat the same field (and if doing animation, with different picture information). So on a large-ish screen CRT, you can see faint horizontal lines between the lit pixels. This is the lack of scan lines due to the 'missing' field.

Most
That was afaik done by some game consoles too. A pseudo progressive display by adjusting the two fields to not have the 1/2 scanline offset, causing both fields to be overlayed and scanline gaps between the lines.

That's what I expected the Electron to be like too but it appears to use a hybrid approach. It has the 1/2 scanline offset, but shifts the vsync start around each field.
Last edited by hicks on Mon Jul 02, 2018 10:39 pm, edited 1 time in total.

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Re: BBC releases computer history archive

Post by Coeus » Tue Jul 03, 2018 11:33 am

Back to the content of these programs, I am now working my way through "The Computer Programme" and I think these are a fascinating piece of history not just for technology but the social attitudes and concerns and also lots of filming inside places I have never been. There are also old cars, old telephones and, I think in one of the previous programmes, describing the CD that was going to be the new thing in music distribution and which has since seen its peak and is now in decline.

There are quite a few non-BBC microcomputers in some of the programs, most of which I don't recognise - I do recognise the Commodore Pet. Later, when I have more time, perhaps I could grab a screen dump of the table with a selection of them and see if anyone else knows what they are.

It's always interesting to look back with hindsight. I mentioned the IBM PC in the other thread about the BBC Micro spec and, while not available at the start, the time period of these programs is also a period in which the PC was developing but one in which I wasn't really taking any interest in it. I had been very happy with the BBC micro all the way through school, had just started to look at some of the newer home computers but didn't bother in the end when I had Unix workstations to play with. The PC by comparison seemed like a bit of a bodge - a processor that seemed like it was designed on the basis that what people really wanted from a 16/32 bit processor was to run more of their ex-8bit, 64K programs at the same time, a bit liked banked MP/M but with segments instead, while the DOS operating system favoured running one, bigger program - though not too big, of course and lacking features like interrupt driven serial I/O that the BBC micro had.

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Re: BBC releases computer history archive

Post by BigEd » Tue Jul 03, 2018 1:11 pm

Quite a few interesting bits of info in this 1986 programme:
Micro Live Series 3 Episode 1
- Amstrad's new PC cheaper than other clones
- Sugar tells software companies to drop prices and sell more copies to make more money
- IBM's profits drop by a billion per quarter due to clones
- Sir Clive reckons the PC is now long in the tooth and both IBM and Amstrad need to move on
- Brian Long of Acorn reckons their job is to make the expensive innovative machines which Amstrad can cost-reduce in due course
- Sir Clive says he's free to make further computers, even though he's sold the Sinclair name
- The latest Spectrum (from Amstrad) looks rather like an Amstrad
- Sir Clive says the QL was a misjudgement - 8 bits is enough for anyone
Edit:
- Acorn back in profit, Master more popular than expected, and the new Compact is out
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Re: BBC releases computer history archive

Post by Commie_User » Wed Jul 04, 2018 2:02 pm

We're only talking about the 80s and the past is a foreign country already.

I bet if we were shot back there because we love our BBCs so much, we'd have more culture shocks than we'd care to admit. Yet everything would still seem so familiar.

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Re: BBC releases computer history archive

Post by sbadger » Wed Jul 04, 2018 4:53 pm

Commie_User wrote:
Wed Jul 04, 2018 2:02 pm
We're only talking about the 80s and the past is a foreign country already.

I bet if we were shot back there because we love our BBCs so much, we'd have more culture shocks than we'd care to admit. Yet everything would still seem so familiar.
My kids don't understand when we go on holiday and they can't pause telly!
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Re: BBC releases computer history archive

Post by Commie_User » Wed Jul 04, 2018 4:56 pm

Well it takes living in a richly advanced place to emulate a time warp as well as live in one. :)

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Re: BBC releases computer history archive

Post by Elminster » Wed Jul 04, 2018 5:22 pm

sbadger wrote:
Wed Jul 04, 2018 4:53 pm
Commie_User wrote:
Wed Jul 04, 2018 2:02 pm
We're only talking about the 80s and the past is a foreign country already.

I bet if we were shot back there because we love our BBCs so much, we'd have more culture shocks than we'd care to admit. Yet everything would still seem so familiar.
My kids don't understand when we go on holiday and they can't pause telly!
It is the cold water showers that get me

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Re: BBC releases computer history archive

Post by Coeus » Sat Jul 07, 2018 6:35 pm

Does anyone recognise the chip shown in episode 9 of "The Computer Programme", "In Control" at around 18 minutes. The chip being held has Ferranti on it so a ULA, possibly? That would be consistent with Ian McNaught-Davis taking about customising the chip to a particular purpose as the last step in the manufacturing process, i.e. I assume he is talking about the final mask? But is the layout shown on the wall of a ULA? Isn't it a bit too irrelgular for that?

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Re: BBC releases computer history archive

Post by tricky » Sat Jul 07, 2018 6:47 pm

I don't know, but I thought that ULAs were very regular Under the metal layer.

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Re: BBC releases computer history archive

Post by BigEd » Sat Jul 07, 2018 6:52 pm

I'm going to guess it's the serial ULA... probably wrong but it looks a bit like it has a regular 9-bit structure in there.

The nature of a ULA is that it has a very regular array of transistors, and all the lower levels of the chip, and it's just the final top metal layer which is customised for a given purpose. So you'd expect the metal layer to be less than completely regular. (Having only one layer customised makes it both cheaper and faster to produce the end product - the semi-customised chips.)
EP9-ULA.png
Edit to add:
Program clip here
EP9-ULA-again.png
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Re: BBC releases computer history archive

Post by guesser » Sat Jul 07, 2018 8:15 pm

The "border" for want of a better word between all the gates and the bond pads looks very "ferranti" when you look at die shots of various series of ULA.
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Re: BBC releases computer history archive

Post by Coeus » Sat Jul 07, 2018 8:58 pm

First programme in the series "Making the Most of the Micro" has a very cool bit with Ian McNaught-Davies appearing to walk over a macro image of what looks like it may be a BBC micro, but not an issue 7 as far as I can see. I assume the effect is a colour separation overlay?

Anyway, the featured circuit board has the CPU in the centre, an SAA5050, the modulator in the right place, the RAM in the right place but the ROM area looks different with a missing connection and the ROMs in odd positions. Here are some stills:
on_cpu.png
Sitting on the CPU
ram.png
The RAM
on_basic.png
Standing on what he claims is BASIC
So the last one is where things look odd. Ian is standing on a ROM he claims is BASIC and indicates the ROM to our right (his left) is the OS but relating this to my issue 7 board by position these would both be paged ROMs with the OS off to the left. There is also a missing connection but maybe this is a Model A?

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Re: BBC releases computer history archive

Post by CMcDougall » Tue Jul 10, 2018 10:55 pm

https://computer-literacy-project.pilot ... 7243292bdb

got this link from Barrie /'OneSwitch' & thought would share, as it's Very interesting about special needs folks using
computers in 1984.

most of the programs are using the Micromike discs he sent me for archiving, & they are in this video.

rather Amazing stuff for back then! :shock: 8)
ImageImageImage

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Re: BBC releases computer history archive

Post by DutchAcorn » Wed Jul 11, 2018 5:19 am

Coeus wrote:
Sat Jul 07, 2018 8:58 pm

Anyway, the featured circuit board has the CPU in the centre, an SAA5050, the modulator in the right place, the RAM in the right place but the ROM area looks different with a missing connection and the ROMs in odd positions. [snip]

So the last one is where things look odd. Ian is standing on a ROM he claims is BASIC and indicates the ROM to our right (his left) is the OS but relating this to my issue 7 board by position these would both be paged ROMs with the OS off to the left. There is also a missing connection but maybe this is a Model A?
I’d say the OS rom is missing or in the wrong socket. And it looks like a model A, with only part of the RAM installed and the missing tube connector.
Paul

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