6 Aug
2015
6 Aug
'15
9:19 a.m.
On 08/06/2015 08:35 AM, Al Kossow wrote:
Formatted Pertec is a fairly simple interface. Chuck
has talked in
the past of designing one, and some of the gotchas with the
interface.
Qualstar built two different styles of Pertec-SCSI adapter for the
1054. I'll see about putting board pics and rom dumps up, but as has
been discussed, SCSI has problems when talking to tapes.
I think Pertec - Ethernet is the way to go, and not mess around with
SCSI or USB.
I've got the Verilog for an XC95128 CPLD checked out--and have tested
the programming on one in a testbed lashup. The interface is basically
"wishbone", via a single 8-bit port and 3 address lines. All of the
detail, such as parity generation, error latching, etc. is handled by
the CPLD. Done that way mostly to create a generic interface without a
lot of SSI packages. I can talk to it directly from a PC parallel port.
Rolling your own is easy. The interface is basically unidirectional
open-collector. You could probably do it, if you weren't too fussy,
with an 8255 or two.
For me, that "last mile" is a bit of a problem.
Is the goal simply to grab all the data from a tape and save it? Then
an interface to, say, an SD Card is both cheap and affords plenty of
space. Or is something wanted that gives immediate control over the
tape drive--that is, something like SCSI? USB and Ethernet are both
attractive, but you'll have to work out the host-side driver software.
Does anyone still *write* tapes any more, save for the occasional
copying task?
Lots of questions with no clear answers.
--Chuck