Re: KA410 Boot Failure With TKZ-50

[Johnny Billquist <bqt%update.uu.se@localhost>]

On 2020-06-13 23:24, Mouse wrote:
> > Reno or dot something or other
>
> 4.4-Reno is not NetBSD 1.anything.  I _think_ Reno came before all
> NetBSD versions, but I wasn't involved with it that far back, and I
> don't recall what I've read of the history in enough detail.  But I
> _think_ Reno was ancestral to 4.4-Lite, and I _think_ NetBSD was
> derived from 4.4-Lite (via the Jolitzes' work).  But I could easily be
> wrong about either or both of those.

More or less, yes. Reno is a little more formally "BSD 4.3 Reno". It 
came after the 4.3 release, and was a step towards 4.4.
So ancestral in that way, definitely.

I probably still have a tape somewhere for VAX of 4.3 Reno.

It definitely predates any NetBSD.

> > It's probably the SCSI layer.  Do I implement TMSCP(sp?)
>
> TMSCP is not SCSI.  TMSCP is the tuned-for-tapes version of MSCP, DEC's
> Mass Storage Control Protocol.  MSCP is a protocol run between hosts
> and disks; TMSCP is an adaptation of it designed for tapes.

Right. Also (T)MSCP is purely a software layer. It can be used by 
controllers which various different technologies for actual low level 
connection, as well as higher layer interfaces which acts as the 
physical layer from the (T)MSCP point of view.

As such, there are (T)MSCP controllers which use SCSI, just as there are 
those using SDI or STI, or ST412, or other technologies as well.

> Given the questions you were asking, I would say it is highly unlikely
> you will need to implement TMSCP.  The only cases I can see where you
> have a need to implement TMSCP are (1) building an emulator of some
> sort, (2) writing host code to speak to DEC tapes, or (3) building a
> glue layer, such as a board that speaks TMSCP to the host and SCSI to a
> drive.  It does not strike me as likely that you would be taking on any
> of those while still having occasion to ask what you were asking.

I would agree. Unless you want to interface either with a real DEC 
computer, or a real DEC disk/tape, (T)MSCP is probably not relevant.

  Johnny

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