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38 votes

BBC/Acorn BASIC, what made it so fast?

There are a number of optimisations which, in aggregate, will improve performance somewhat: There are multiple linked lists for the variables, one per first letter of the variable name. This makes ...
pndc's user avatar
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37 votes

How were Acorn Archimedes used outside education?

One early killer app for the Acorn Archimedes was Sibelius 7, a score-writing program. It was so good that many musicians, composers etc. bought Archimedes computers just to be able to run Sibelius. ...
Stephen Kitt's user avatar
35 votes
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Was the first ARM "processor" a BBC BASIC program?

Per Sophie Wilson: To prove that [Steve had] designed the microarchitecture correctly, he wrote, in BBC BASIC, a model of the microarchitecture. To prove that I'd designed the architecture ...
Tommy's user avatar
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29 votes
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How did the Sideways address space work?

Sideways ROM (also RAM in later models) was paged into the processor's address space. Sideways memory sat in the address range from $8000 to $BFFF. The BBC Model B had four slots on the motherboard ...
Chenmunka's user avatar
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24 votes

How were Acorn Archimedes used outside education?

Omnibus Systems in the UK used the Acorn Archimedes (and later Risc PC) hardware for television on-screen graphics overlays, intended for use in live broadcasts. Millipede systems built the Alphalock ...
Simon Farnsworth's user avatar
20 votes
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Why did Acorn's A3000 have red function keys?

The red function keys were a carry-over from the days of the BBC's Computer Literacy Project. The first computers made for the BBC by Acorn, the Model A and Model B featured red function keys: These ...
Kaz's user avatar
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19 votes
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When did half-bad RAM chips stop being available?

Sinclair's use was a very unique case in a very specific situation that never occurred again later on. Production side: There were many more manufacturers of chips back then. The ones that wanted to ...
Raffzahn's user avatar
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18 votes
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BBC/Acorn BASIC, what made it so fast?

Most of BBC BASIC's speed advantage came from Acorn's use of a 2 MHz 6502 with fast 4816A RAM chips. It's a good interpreter, but it's the hardware that makes it near-mythically fast. To confirm this, ...
scruss's user avatar
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18 votes
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Reading the BBC Domesday Project

Reading up on various preservation efforts, including the Center for Computing History's, and information collected on Andy Finney's and Adrian Graham's sites, it appears that the most difficult part ...
Stephen Kitt's user avatar
15 votes

What BBC Microcomputer features were requested specifically by BBC engineers?

Linear power supply was not a BBC engineering requirement by the time I joined Designs Dept in late 1981. Perhaps it was dropped well before actual production; I don't know if that was pushback from ...
user_1818839's user avatar
13 votes
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How long was the production run for the Acorn Electron?

According to The Register’s history of the Electron, production had stopped before the Olivetti cash infusion; in February 1985: But the Electron, seen to be low on Olivetti’s list of priorities ...
Stephen Kitt's user avatar
12 votes
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Why does my Acorn RiscPC display the POST boot error?

What does "POST" mean? On the RiscPC, "POST" stands for Power On Self Test. The POST sequence is performed on computers running RiscOS 3, and ensures that the computer is working ...
wizzwizz4's user avatar
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12 votes

Acorn Electron to VGA/HDMI?

It cost me something like $50 all up to connect my Electron to the TV using an RGB to SCART cable (this one from eBay) and an RGB to HDMI converter like the one pictured below: You can get this model ...
Phillip Pearson's user avatar
12 votes

How were Acorn Archimedes used outside education?

The late Chris Bell used an Archimedes to control a custom CNC machine that milled EGGrings high performance bicycle chainrings. Chris was a former teacher in the UK, and founded the company just at ...
scruss's user avatar
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12 votes
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Please identify this program for Acorn Archimedes

That would be 1st Word Plus. This blog contains a full screenshot of it in use (via an emulator).
Kelvin Sherlock's user avatar
11 votes

Acorn Electron to VGA/HDMI?

The Electron outputs an analogue interlaced 625-line image, with a line rate of 15.625Khz. HDMI is a digital input, so cannot comprehend the Electron's analogue output. VGA is analogue but many ...
Tommy's user avatar
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11 votes

How can I hook up my Acorn RISC PC 600 to a LCD monitor?

The RiscPC was Acorn's first to use a separate RAM bank for the video. It was intended that the video drivers would auto-synch to the monitor. However, there was often a failure to synch, leaving ...
Chenmunka's user avatar
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11 votes
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Screen "garbage" in Acorn Electron games

Yes. The BBC has a Motorola 6845 generating its screen addresses. That's a flexible chip, with which the developer has wide control over screen sizing and placement. The Electron has a custom ULA ...
Tommy's user avatar
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11 votes
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Would compare-and-branch have added an extra cycle on ARM-1?

If I remember rightly (I worked at Acorn during the period ARM was designed and built, but I'll admit my memory for casual conversations from that time is far from perfect) the argument was that the ...
Graham Toal's user avatar
11 votes
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Why doesn't the Acorn Electron use fast page mode?

This diagram comes from page 7 of the Electron service manual: As you can see, both CPU and VDU accesses involve a single RAS and two CASs. It is therefore using page mode.
Tommy's user avatar
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10 votes
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Is it still possible to access a BBS via dial up internet on the C64 (or other retro computers)

There are many and you can always create your own. The BBS Corner has a number of links to some that are running and links to software. It is true that many old BBSs still (sort of) running are now ...
Chenmunka's user avatar
  • 8,141
10 votes

What BBC Microcomputer features were requested specifically by BBC engineers?

Seemingly predating that StarDot thread by a few years, I found this list of documents that includes "HardwareSpecification.txt", "BASICOutline.txt" and a few others that are "(c) Copyright BBC 1981" ...
Tommy's user avatar
  • 36.9k
10 votes

Would compare-and-branch have added an extra cycle on ARM-1?

Yes, it would add a cycle. How do you branch on ARM? add pc, pc, #8 That's a bit of an over-simplification, but the point is that ARM was meant to be purely orthogonal, that is, the program counter is ...
Renee Cousins's user avatar
9 votes

Would compare-and-branch have added an extra cycle on ARM-1?

Remember that classic AArch32 code has conditional execution of most instructions, which more or less demands a condition code register in simple implementations. Once the ARM designers had included ...
John Dallman's user avatar
  • 13.2k
8 votes

Was the first ARM "processor" a BBC BASIC program?

This isn't really an answer to the question, but the comments repeatedly talk about Sophie Wilson's claim to be able to execute 100k+ ARM instructions per second. This is an impossibility on any ...
JeremyP's user avatar
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7 votes

Is it still possible to access a BBS via dial up internet on the C64 (or other retro computers)

There are still a lot of retro-BBS out there, accessible via dial-up or telnet (or both). telnetbbsguide has a list. Typically they will work with retro computers (they are often made for that), but ...
dirkt's user avatar
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7 votes

Reading the BBC Domesday Project

It is possible to read the discs using the original Philips player and connecting it to a PC but it requires a low level SCSI driver to be written as the communication is so slow and would time out ...
Alex's user avatar
  • 71
7 votes

Is it still possible to access a BBS via dial up internet on the C64 (or other retro computers)

In the USA, analog landlines are going away in favor of Voice over IP (VOIP). But analog modems (and fax) don't work well over VOIP, depending on the voice codec. You'll want to choose a non-...
snips-n-snails's user avatar
7 votes

When did half-bad RAM chips stop being available?

The Memotech MTX (1984-5 or so) has a wire link on its circuit board that allows you to use half-good chips. I dont think I’ve seen any being used, but it seems the designer thought it at least ...
Andy Key's user avatar
  • 121
7 votes

How were Acorn Archimedes used outside education?

My dad bought an Archimedes after the QL and the ZX81 because he was scientist and was interested by Archimedes maths specifications of 32 bits. My neighbor was very rich. He was jealous at the time, ...
bandybabboon's user avatar

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