GPIB state machine info WTD
ethan.dicks at gmail.com
Fri Sep 9 13:52:30 CDT 2005
On 9/9/05, Dwight K. Elvey <dwight.elvey at amd.com> wrote:
> As I recall, the GPIB chip made by TI ( forget the number )
> had a data sheet that explained the states. Not much
> to it as I recall, mostly just handshake stuff and address
The common chips are:
> It seemed like there was some timed stuff that
> might not work well in software but for the most part I'd
> suspect that Ethan is right, one could do it all in software.
One issue is to identify what GPIB devices you expect to talk to.
Older ones, especially ones that implemented the protocol via ~1MHz
8-bit microprocessor, are unlikely to be able to handle 1MB/sec speeds
that the newer "IEEE 488.2" devices can. If all you want to do is
talk to old devices at a few KB/sec, it really doesn't matter if you
have a hardware or a software implementation. For the newer,
high-speed stuff, I'd expect you'd need an ASIC to pump the bytes
through in a timely fashion.
OTOH, even Commodore had a little fiddly hardware thing to handle
handshaking turn-around. Andre Fachat mentions that in his extensive
pages covering Commodore hardware and his own home-built
mostly-PET-compatible 6502 computer. I do not know about the
Commodore acoustic couple (C810?), but disks and printers tended to
have 6502/6504/etc software implementation of GPIB.
More information about the cctech