21 Mar
2020
21 Mar
'20
4:12 a.m.
On 2020-03-21 04:04, Robert Armstrong wrote:
? With all this social distancing and staying home,
I?ve been dusting
off old hardware and fixing it up.? I just finished running diagnostics
on a nice little PDP-11 system.? It is a -
?????????????? PDP-11/53+ with 3.5Mb RAM in a BA123
?????????????? KDA50 and 2xRA73 drives
?????????????? DELQA NI
?????????????? CXA16 16 line mux (DHV11 clone, more or less)
?????????????? TQK70 and TK70 (probably worthless ? those things never
work)
?????????????? SQ739 SCSI controller (does both MSCP and TMSCP!)
Nice setup.
?? I figure I?ll use the SCSI for a CDROM and a tape
drive, maybe an
Exabyte.? Don?t really need more disk space with two RA73s already, and
I?m sure the SDI is faster than the SCSI.
Actually, I would probably suspect SCSI would outrun the SDI. We have
four RA73 on Magica (11/70), and at home I have SCSI on an 11/93.
So it is a little tricky to do a simple comparison, but I get roughly
two to three times as many I/Os per second on my 11/93 with SCSI.
One big reason is probably that I have fairly "modern" SCSI disks, so
seek times are way better than the RA73s have.
? So, the question is, what OS should I put on it??
RSX or RSTS?? It
has to be something that can make good use of the hardware.
? No Unix, please ? I?ve already got a nice 11/83 with 2.11bsd on it.
? Ideas?
Of course I would vote RSX. :-)
Well, actually, have you used either OS before? If you feel familiar
with one or the other, it might be a good starting point.
With RSX, you do have TCP/IP, and a bit more DECnet functionality, but
otherwise I don't think the difference between them are that big. They
certainly are rather different, but if you're alone on the system more
or less, it makes less of a difference.
And by the way, the TK70 I have found to generally be pretty good a
reliable. The TK50 is the horrible one. At most, I have needed to clean
the heads on TK70, but otherwise they usually run just fine. But if I
get a TK50, I might as well just toss it out...
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol