Acorn IEEE488 interface
julesrichardsonuk at yahoo.co.uk
Sun Dec 11 15:13:29 CST 2005
Tony Duell wrote:
>> I've also got the schematic for the Acorn System IEEE488 card somewhere - it
>> wouldn't surprise me if the BBC unit is based heavily on this (I don't think I
> It might be, it might not. The 'Acorn' IEEE-488 interface for the Beeb
> doesn't seem to be an Acorn design.
> The article to find is in 'Electronics and Wireless World' February 1984,
> pages 24-26 ('IEEE488 interface for the BBC Microcomputer'). It imples
> the interface was actually designed by a company called 'Intellegent
Aha. I've dug my unit out - on the back it says "Made in Britain for Acorn
Computers" - rather than "by Acorn". There's no manufacturer's name written
inside - but there is an "II" beside the Acorn part number on the PCB.
> The other useful thing in this article is an example program using the
> IEEEFS filesystem ROM, and a list of the commands you can use with the
> interface. It appears you open a 'file' called "COMMAND" and another
> called "DATA", you write command strings to the first one and use the
> second one to actually transfer data on the bus. Addressing looks totally
> strange, you seem to open a file with a name correspodning to the device
> address in decimal and then use the file handle of _that_ file in
> subsequent comamnds. Hmmm...
Hmm, I see what you mean. The manual looks very comprehensive with lots of
examples - but I can't see where it justifies why the addressing is done in
>> I *think* Tony Duell (on this list) has one too. Other than that, those are
> I do. I think I might also have the IEEEFS ROM that goes with it, but I
> can't promise that.
I certainly don't have one...
> You;'ve just made me worried. I am going to have to try to find my unit
> to see if it agrees with the circuit in Wireless World.
From your description, the one that I have certainly does - 9914 IC, 5MHz
clock, 75160 and 75162 buffers.
I *think* we've got a stack of Electronics and Wireless World issues, so I'll
have to look for the article...
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