7 Jul
2006
7 Jul
'06
11:11 a.m.
Jules Richardson wrote:
One compensating factor is that the drives that typically are
involved will be small (tiny?!). It's not like trying to move
100GB! :>
I'm not sure if the "8MHz I/O bus" applies to newer PC's
(i.e. is it throttled down someplace) which would limit
accesses to the printer port hardware -- nor any limitations
on other hardware platforms. But, I am guessing you can
probably get 250-500KB/s through this interface. Not
stellar but sure beats DC!
Don Y wrote:
I hadn't thought of adding ATN (though I was debating supporting
the parity *signal* -- but not the logic) but it shouldn't be
a problem. The issue will be in the software (though even
that can probably be "solved once" and remembered)
I'm just finishing up some ideas on a
quick-and-dirty
parallel port (SPP)-to-OMTI interface (so Jules can
salvage his "bits" :> ). Anyone like to add their
two cents?
Thought for the morning - it'd be nice if the hardware was switchable
between SCSI and SASI. In a moment I'll dig out the docs I have for the
Omti 5x00, Adaptec ACB4000, Xebec (umm, 1452 or something like that) and
the Emulex boards.
Some of those boards are SASI, some are SCSI (although I think all are
pre-CCS, but that's a software issue). What needs to be understood is
whether the extra handshake lines needed for SCSI can be included - and
if so can they be 'switched off' via either hardware or software to
drive a SASI device... (from memory, the OMTI is the closest board to
'real' SCSI, so designing
against that's likely a good thing)
One of the manuals (model 20?) that I have didn't support
parity so I hadn't yet planned on that (but will).
Note that I am
not aiming for performance. Just
a way to coax bits off a disk drive so they can
be imaged properly (is that correct, Jules?)
Yep, doesn't matter if it takes a while to run or chews CPU cycles to do
so - it's purely a way of imaging / restoring disks, not a way of
interacting with them (that can be done via the loopback device in Linux
once you have an image!)