26 May
2004
26 May
'04
9:18 a.m.
try a seagate st01 controller. they are supported by linux drivers
you can rob for information on driving them.
I suspect you'd have problems with the select sequence if using
a printer port. there are some things that are best done in hardware
even with the oldest scsi.
I think that the ST01 is dumb enough you can do anything you want
implementing the initiator state machine and have complete control to
handle what are now considered bugs by newer chips like adaptec
chips, etc that fully implement a lot of things for you, such as message
byte reading, and phase decodes.
Jim
Jules Richardson wrote:
Hiya,
has anyone got a early copy of the SCSI spec which just covers SCSI 1
(i.e. 8bit bus, 5Mb/s transfers only)?
I want to see if I can get the parallel port on a modern PC hooked up to
one of the old SCSI/ST506 bridge boards that I have, but given that I
only have 12 data out lines to play with and 5 data in (13 in if I
assume a bidirectional port) things are pretty tight and I obviously
need to do some loading of stuff into external registers.
I've got some reasonable info on the SCSI protocol, but having a better
idea of which signals do what (and at what time) would be useful.
All the docs out on the web seem to be for the latest SCSI revision
though (and therefore contain a lot of info that I don't need).
Furthermore I only really need the low-level protocol now;
software-driven higher level command structure can wait for a few days!
cheers
Jules