6 Jan
2014
6 Jan
'14
11 p.m.
I wasn't aware of sendtape; that looks useful.
The real long term goal for the beagleboard is put the pdp8's serial port
on my home network. There is a public domain program called ser2net that I
use at work which maps serial ports on a server to telnet ports. Thus you
can just type something like 'telnet foo 2000' from a host and if port 2000
on machine foo has a ser2net server sitting on it that is connected to
/dev/ttyXX then basically you get that serial port tunneled to your
laptop/pda/whatever.
What I'm thinking of doing is running ser2net on the beagle and modifying
the code so that it not only listens to the serial port but also has access
to the reader flag. Thus when the flag is set output can come from a file
and when it goes low normal terminal operation resumes.
Marc
On Mon, Jan 6, 2014 at 12:39 PM, Ian King <IanK at livingcomputermuseum.org>wrote:
-----Original
Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Marc Howard
Sent: Monday, January 06, 2014 11:24 AM
To: General Discussion: On-Topic Posts Only
Subject: Easiest way to get MAINDEC diags onto a PDP-8 (sans paper tape)
Hi,
I've been bringing up a PDP-8a system over the past few months. It has
2 x
TU56 (TC08 controller), 3 x RK05J and a 3rd party
RX01 dual floppy. The
processor itself is an 8e board set w/EAE and 32K core.
As for media I have 7 RK05 packs, one floppy and about 60-75 dectapes.
My first attempt at booting was with the RK05. It took a ton of
cleaning (and
capacitor replacement/reforming) to bring up the
8, followed by cleaning
one
of the RK05 drives. (BTW, this stuff apparently
was in the equvalent of
a barn
for at least 20 years by what I could see).
Anyway I cleaned 2 of the RK05 packs that seemed most likely to be
bootable
media but no joy. The drive just seeks to
cylinder 0 and sits there,
although I
think a data transfer *might* have occured. I
suspect that all of the
RK05
packs were for individual user backup.
Apparently from the
documentation I
have this system at one time had a RL01
attached.
Next I worked on the better looking of the two TU56's. I've got one
drive
shuttling okay; the other half has no torque in
one direction; I suspect
I need
to replace yet another AC motor run capacitor.
The TC08 checked out okay and I replaced all of the das blinken lights
with
new bulbs, it looks really cool.
Then the big test. I picked out a tape that had a listing with it
indicating that
it
was a system tape of some sort (Focal, editor,
etc.)
I toggled in the TC08 boot code (since my M8317 has the wrong boot roms
for
it) and hit run. The tape wound back to the
beginning, reversed, seemed
to
transfer many blocks of data and then just spins
in a loop.
So the next step would obviously be to run some TC08/TU56 diagnostics
but I
don't have any way of loading them.
If I had an RK05 pack with OS8 + diags on it that would work but I don't
see
that happening. Perhaps another alternative
would be to get the
equivalent
on RX01 floppies from someone, but I don't
even know if the floppy system
works yet.
So for now I think figuring out how to make a combo terminal emulator/raw
data file thingy might be the best way to go. I'm thinking of putting a
beagleboard to use for this unless anyone out there has a simpler/quicker
solution.
Suggestions anyone?
When I was bringing up our 8/e, the last idea you mentioned is what I did,
just from a laptop with a terminal emulator and use David Gesswein's
sendtape program to load diagnostics from papertape image. The TC08 has
several adjustments that can easily get out of trim, and the standalone
diagnostic for it includes several scope loops to make it easier to adjust
those. Of course, you still have to sort your way through a gazillion
wirewrap pins and get the scope probe on the right one.... -- Ian