Re: KA410 Boot Failure With TKZ-50

[David Brownlee <abs%absd.org@localhost>]

On Sun, 14 Jun 2020 at 18:21, Johnny Billquist <bqt%update.uu.se@localhost> wrote:
>
> On 2020-06-14 19:02, Rhialto wrote:
> > Sorry if I am confusin things here, but...
> >
> > On Sat 13 Jun 2020 at 22:15:32 -0400, Thor Lancelot Simon wrote:
> >> The TK50 hardware implemented neither TMSCP nor SCSI.  It implemented a
> >> very minimal proprietary protocol over a very, very slow serial connection
> >> (200Kbit/sec) to one of two possible controller cards: the SCSI TKZ50 or
> >> the QBus TQK50.  An 80186 (I think; might have been an 8085) on the
> >> controller card interfaced to one of the two possible host buses.
> >
> > I have (packed away) a TK-50 drive and a TKZ-50 drive. I also have a
> > uVAX 2000 (KA410) and a uVAX 3100 (and also a VAXstation 3100). One type
> > of drive came with the one VAX, and the other with the other.
> >
> > In my recollection, which may of course be off, it was the TK-50 (not
> > SCSI, but cabling etc looks the same) that came with the 2000, and the
> > TKZ-50 (SCSI) came with the 3100.
> >
> > So perhaps $SUBJECT occurs because it is the wrong type of tape drive?
>
> No, I'm pretty sure the TKZ-50 was explicitly made for the uVAX2000.
> That machine only have an MFM interface for disks, and a SCSI
> controller, who's only purpose was to connect to the tape drive. There
> were nothing else in it.
>
> Also, the form factor of the TKZ-50 case is identical to the uVAX2000,
> and they were stacked on top of each other, if I remember right.

The KA410 (or RD disk formatting unit as it was also known :). It was
indeed easy to confuse a uVAX 2000 with its tape box from the right
angle.

I thought the tape drive was a TK50Z (-FA/GA?), though this is from
unrefreshed memories from helping to build and test the NetBSD 1.3.X
VAX tapes on a uVAX2000 and various VAXstations, it was always "the
TK50Z".

The KA410 can boot from SCSI tape (TK50Z), a supported RD drive
(likely RD31, 32 53 or 54), or network (you grow to like the ability
to MOP a NetBSD bootloader :-p). Once booted you can drive any
hardware your chosen OS supports, so SCSI disks, scanners, tape
changers all become feasible.

David