SCSI Questions (Was: "Re: Purchased a Microvax 3800")

Johnny Billquist bqt at
Mon Dec 7 13:29:49 CST 2015

On 2015-12-07 20:25, Christian Gauger-Cosgrove wrote:
> On 6 December 2015 at 13:24, Mark G. Thomas <Mark at> wrote:
>> As much as I love old CPUs, I've lost my patience with hard disk drives.
>> I've been using AztecMonster (search ebay) CF-SCSI adapters, with several-GB
>> CF cards instead of spinning disks. The KA660 and several PDP-11/83s
>> here run reliably from CF storage. I see now there are SCSI2SD cards for
>> half the price of the AztecMonster CF adapters I've been using. These
>> might be an alternative, if they play okay with whatever q-bus SCSI
>> controller you find. Installing from SCSI CDROM and using flash
>> storage is definitely the way to go if you can get the parts.
> That's great news to hear that the AztecMonster works on QBUS PDP-11s.
> I now know exactly what my future plans are...
> But I have a "random" question for those here. I know some of the QBUS
> (and UNIBUS) SCSI controllers can act both as an MSCP and TMSCP
> controller. (CMD CQD-220A/TM for one example.) And I know that several
> of the PDP-11 operating systems install from tape, and can install
> from TMSCP tape (hello RSTS/E). What I'd like to know is: Is there
> anything out there that can emulate a SCSI tape device on a CF card/SD
> card/USB stick/what-have-you?

I think all (modern PDP-11) OSes can install from TMSCP tapes. RSTS/E is 
more picky than some others, though, if I remember right...

As for your actual question, that is outside the scope of the PDP-11. 
You are asking if there is some SCSI storage, that physically looks like 
a CF card (or so), but logically on the SCSI bus looks like a tape.

Hooking that to a PDP-11 or an x86-64 wouldn't make any difference.


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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