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

[Mark G. Thomas]

Hi,

On Mon, Dec 07, 2015 at 02:25:25PM -0500, Christian Gauger-Cosgrove wrote:
> On 6 December 2015 at 13:24, Mark G. Thomas <Mark at misty.com> 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...

I had mixed results with some QBUS SCSI adapters. Some played well
with the AztecMonster and some did not. Oddly, I think my Emulex UC07
was one that did not, but the CQDs and maybe one other model work fine.

> 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?

So far, I've been using a DLT8000 when I've needed a sequential tape device, 
such as for the BSD2.11 install. It's been convenient to write the tape on
a Linux or Sun box, then plug it into the PDP11. All my older SCSI tape 
drives (Exabyte and DAT) have developed problems, but this DLT8000 drive 
works great.

Mark

-- 
Mark G. Thomas (Mark at Misty.com), KC3DRE