11 Dec
2005
11 Dec
'05
7:19 p.m.
On 12/11/2005 at 4:54 PM Jules Richardson wrote:
Eelco Huininga wrote:
> Does anyone have any documentation or software (other than IEEEFS 0.5
> and NIEEE 0.2) for Acorn's IEEE488 interface for the beeb?
On a slight tangent--is there really anything else required for
medium-speed HPIB support other than a bidirectional 8-bit port with a few
handshaking lines? It seems to me that th Victor 9000 advertised IEEE-488 From waht I rememebr you can do almost all the IEEE-488
stuff purely in
software (the handshake is interlocked, in that something is
changed by
one device. then the other device changes some other line, then the first
device can change a line, etc. THere's no chance of missing anything). I
did say 'almost all' -- IIRC there's one thing you can't do like that,
you need to do it in hardware. But it only takes a couple of gates.
Commodoe, and even HP, did do the HPIB interface in software in some of
their machines. For example the HP82169 HPIL - HPIB interface contains a
custom HPIB buffer chip, but it is just a buffer. The actual logic is
handled by the microcontroller (8049 IIRC).
capability with little more than a "dumb"
parallel port.
IIRC, (and I don't haev the schematic in front of me) the Sirius (Victor
9000) used a 6522 with some propper HPIB buffers (75160, etc). This was
used for the Centronics parallel port, but with the right cable and
software it could be used as an IEEE-488 port. Alas I've never seen the
'right software'
-tony