Wanted: Pertec Tape Controller

[Chuck Guzis]

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