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.
###CONNECTED TO NODE BROCK(W1MV-7) CHANNEL A
Welcome to BROCK (W1MV-7) in Brockton, Mass
ENTER COMMAND: B,C,J,N, or Help ? C KZ2X-3
###LINK MADE
Trying 44.44.107.8...
Connected to
sim.kz2x.ampr.org.
Escape character is 'off'.
HSLA Port (d.h001,d.h002,d.h003,d.h004,d.h005,d.h006,d.h007,d.h008,d.h009,d.h010,d.h011,d.h012,d.h013,d.h014,d.h015,d.h016,d.h017,d.h018,d.h019,d.h020
,d.h021,d.h022,d.h023,d.h024,d.h025,d.h026,d.h027,d.h028,d.h029,d.h030,d.h031)?
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
Password:
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
ls
Segments = 5, Lengths = 4.
r w 1 KZ2X.profile
r w 1
start_up.ecr 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
logout
KZ2X.Ham logged out 12/21/21 1722.9 est Tue
CPU usage 0 sec, memory usage 0.2 units, cost $0.12.
###DISCONNECTED BY KZ2X-3 AT NODE BROCK