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* [COFF] Multics comes to amateur radio.
@ 2021-12-22  1:56 Dan Cross
  0 siblings, 0 replies; only message in thread
From: Dan Cross @ 2021-12-22  1:56 UTC (permalink / raw)
  To: COFF, multicians

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Chalk this up to "pointless hack" but I know many COFF readers (and
presumably some multicians) are also ham radio enthusiasts, so perhaps some
folks will find this interesting. I have succeeded in what I suspect may be
a first: providing a direct interface from AX.25 amateur packet radio
connections to a Multics installation (and TOPS-20).

I've been interested in packet radio for a while and have run an AX.25
station at home for some time, and I have configured things so that
incoming radio connections to a particular SSID proxy into telnet to a Unix
machine on my AMPRNet subnet. I don't run the traditional AX.25 "node"
software, but can log directly into a timesharing machine in my basement,
which is pretty cool.

Some recent upgrades provided an opportunity for a project interfacing
"retro" computer instances with packet radio. AX.25 is a slow medium: 1200
BAUD (this is on 2m) packed switched over a high-loss, high-latency RF
path. While my Unix machine does all right, it occurs to me that systems
designed in the teletype era might actually be better suited to that kind
of communications channel.

So I set up a DPS8/M emulator and configured the packet node to forward an
SSID to Multics. After some tweaking to clean up a bizarre number of ASCII
NUL characters coming from the emulator (I suspect a bug there; I'm going
to email those folks about that), things are working pretty well: I can
connect into the system interactively and even use qedx to write PL/1
programs. To my knowledge, no one has done this with Multics before. A
small session transcript follows at the end of this message (sorry, no
PL/1). It's not fast, so one definitely comes to appreciate the brevity of
expression in the interface.

While I was at it, I also installed TOPS-20 on an emulated DECSYSTEM-20 and
got it talking over AX.25 as well. Now, I'd like to set up an interface
reminiscent of a PAD or TIP allowing access to all of these machines,
muxing a single SSID. Sadly I have no idea what the user interface for
those things looked like: if anyone has pointers I can use to craft some
software, I'd be happy to hear about it!

Pointless perhaps, but fun!

        - Dan C.

PS: I'm happy to set folks up with accounts, if they'd like. Shoot me an
email with your call sign. If you're in the greater Boston area, try KZ2X-1
and KX2X-3 on 145.090 MHz.

Welcome to BROCK (W1MV-7) in Brockton, Mass
ENTER COMMAND: B,C,J,N, or Help ? C KZ2X-3
Connected to
Escape character is 'off'.
Attached to line d.h001

Multics MR12.7: KZ2X Multics (Channel d.h001)
Load = 6.0 out of 90.0 units: users = 6, 12/21/21  1718.0 est Tue
login KZ2X
You are protected from preemption until 17:18.
KZ2X.Ham logged in 12/21/21  1718.6 est Tue from ASCII terminal "none".
Last login 12/21/21  1717.0 est Tue from ASCII terminal "none".
No mail.
r 17:18 0.376 54


Segments = 5, Lengths = 4.

r w    1  KZ2X.profile
r w    1
r w    1  hello.pl1
       0  KZ2X.mbx
r w    1  KZ2X.value

r 17:19 0.022 0

who -a -lg

Multics MR12.7; KZ2X Multics
Load = 7.0 out of 90.0 units; users = 7, 2 interactive, 5 daemons.
Absentee users = 0 background; Max background absentee users = 3
System up since 12/21/21  0922.8 est Tue
Last shutdown was at 12/21/21  0917.8 est Tue

    Login at      TTY  Load   User ID

12/21/21  09:22  cord  1.0   IO.SysDaemon
          09:22  bk    1.0   Backup.SysDaemon
          09:22  prta  1.0   IO.SysDaemon
          09:22  ut    1.0   Utility.SysDaemon
          09:22  vinc  1.0   Volume_Dumper.Daemon
          16:41  none  1.0   Cross.SysEng
          17:18  none  1.0   KZ2X.Ham

r 17:19 0.036 0


KZ2X.Ham logged out 12/21/21  1722.9 est Tue
CPU usage 0 sec, memory usage 0.2 units, cost $0.12.

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2021-12-22  1:56 [COFF] Multics comes to amateur radio Dan Cross

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