RT11 SHOW DEVICES command

[Lee Gleason]

I'm looking at RT-11 on a small system here, thinking about using it
for TU58 projects.This system has a DL-like device at the right address
to control a TU58, with no TU58 attached (for now). The DD handler
doesn't load at boot (I didn't expect it to, since the TU58 is missing).
I thought I'd try loading it manually and see what happens. The LOAD
command succeeds. When I do a SHOW DEVICES command, it looks like this.

.SHOW DEV

Device Status CSR Vector(s)
------ ------ --- ---------
DY Not installed 177170 264
DL Not installed 174400 160
DU Installed 172150 154
LD Installed 000000 000
SL Installed 000000 000
VM Not installed 177572 250
RK Not installed 177400 220
DM Not installed 177440 210
DD 143506 176500 300 304
LP Installed 177514 200
LS Installed 176500 300 304
and so on for the rest of the devs.

I was wondering, does it mean anything in particular when the output
for the DD device lists its load address, instead of one of the text
statues (Installed, Resident, etc)?

--
Lee K. Gleason N5ZMR
Control-G Consltants
lee.g...@comcast.net

[Johnny Billquist]

Not sure what it means, but you have both DD and LS installed, and both
use the same CSRs and vectors. That can never end well...

Johnny

[Don Baccus]

Ah, I assume that since LS uses the same CSR and vectors and is known to RT-11, that the DD device is just listed with its install address for the status. Poking at the documentation says that this is one possibility for the status field but doesn't say when it will do it, but I think you've found out.

[Jerry Weiss]

For serial devices like this, you can just load the handler that matches the device plugged into a serial port. I have plotters, printers and TU58 swapped around on identical and/or different CSR/Vectors. It is up to you to keep it straight. The status bits give information on the type of device (disk, read only, serial, etc..) and other functionality the loaded handler can support. Look for RT–11 Device Handlers Manual AA–PE7VA–TC

Jerry