9 Apr
2013
9 Apr
'13
4:31 p.m.
On 04/09/2013 12:08 PM, Arno Kletzander wrote:
Terminator: check.
ID plugs 0 and 1: check.
Cables: no check yet but inbound.
Generally yes. TU58 file format is variable in
that the device appears
to the system as
a blocked volume like disk (though slower). The transfer between the
TU58 and
its host is serial data and the host request block(s) N and not that
much different than
IDE or other intelligent disk system that uses a logial block numbering
system. The
tu58 does not know nor care what is in the 512 byte block. I've run
CP/M from TU58.
Thats plenty of space for PDP-11 OSs. Likely the bad one
has the stuck
head problem
easy to fix. just upen it up and unstick it. There are more detailed
instruction out there.
I'v edone it many times and forget the whole you need a clean room
thing, My first
salvage is near 25years old now.
You can till you have to format or defrag it. I keep a stack of sub 1gb
(from 50mb and up) SCSI drives for that reasonas well as a major
heap of MFM drives (St412s 10mb, St225s 20mb and Quantum
D540s 31mb). I just insert them and image copy to them as backup.
?? (not understanding the above). I should save the controller because the whole
subsystem is bad?
I meant save it for backups or other large data needs as running diags
off it will
be painfully slow. If its bad save it for parts, they are scarce,
usually the
controller is fine and the drive is borked.
allison <ajp166 at verizon.net> wrote:
[RX02 or RX50]
I'm not sure what I'd need it for? There is no other
system within walking distance that would understand the floppy format natively.
Any file I/O thus most likely will happen across the Internet (involving a PC anyway), so
I hoped I'd be fine with the TU58 emulation software discussed below.
I use the PC to make floppies (RX50, RX33 and RX23) and my S100 CP/M
system will
do RX01 transfers.
But, I have multiple Qbus 11s and most all have floppies so portability
between
them is handy. (or a 50ft serial cable).
Mass
storage for my system is another area I need to spend more thought on, for now I was
planning to stay with the RL drives I got with the case.
In the PDP11 world its easy to build a system that forgets portable IO.
A reminder PDP-11 as not a PC and even a 256kb floppy is viable storage
as RT11 fits on it. RL packs
were over 160$ new (...)
cables, terminators and those annoying and scarce drive ID
plugs. If anything the floppy is always a must on my
systems as all my diags and
base RT11 systems are on that media (RX01, RX02, RX50, RX33, RX23).
Are they also
available in TU58 (file) format? A viable uVAX is more than 150mb, (more like
300-500 for V7),
a loaded PDP11 is 30MB. Just difference is OS utilization.
So I guess it all boils
down on what one wants to run on it.
I've got one functional RD53 in it right now, and a second one I hope to revive at
some point in the future. I would not
covet a large drive unless you had the application that
required it.
I thought that we here run large drives just for the kicks of it?!
I do have a TQK(mumble) board already (which was
originally also intended for the VSII), but no drive yet.
Save it as loading diags
from TK50 is both slow and painful assuming the system can boot a tK50 (not guaranteed).
[core]
?? BBU?? Unless you mean BBS7 (Io tends
to use that).
The older LSI11 systems had it if there was a
call for non volatile
memory, the cost was high.
I happen to have 16KW of qbus core. Also core had a far slower cycle
time than Ram of
the day. Core that ran at 1.5us was fast where ram on the day was
under 1us and dropping.
So thus probably not very prevalent and not easy to find
nowadays. Ho hum.
I've also already found out that the memory board I'll be getting is 512k_Bytes_
(256kW) and does _not_ have BBU support. [OS question]
For Unix See PUPS, Pdp-11 Unix Preservation Society.
http://minnie.tuhs.org/PUPS/
One last thing...
Heat! Qbus 11s produce a bit of that. That means fans must all work,
the location
must not be dusty enough to load up the boards and local temperature not
excessively hot.
I fried a 11/23 board while working at the DEC Mill when they had an air
conditioner fail for
the office area, when the room hit 96 (36c), cpu went away, I had plenty
of spares. So reliability
and room temps are coupled. Qbus 11s are fairly tolerent of conditions
but any you find
are going to be old and may not like additional stress.
Allison
Start with RT11 as a base os and it will allow
you to test and get comfortable at lower
cost to learn. It will be transferable knowledge to RSTS or RSX, may help with getting
Unix
on the machine.
Agreed, sounds like a good starting point.