On 2020-06-14 20:15, David Brownlee wrote:
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.
Right. Since low level disk formatting was not always easy to accomplish (DEC wasn't exactly sharing the tools freely), the uVAX 2000 was a good choice for that task, since it had the capability built into the boot monitor, and was even able to do various different non-standard formatting runs.
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".
Damn. I probably have my nomenclature wrong, which Thor also observed. TK50Z sounds more familiar now that I read it.
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.
Yes. And I also know that there was someone on the internet who created a different set of boot roms for the 2000, so that you could boot from a SCSI disk (or atleast my brain says I remember such a thing).
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
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