Date   : Wed, 16 Dec 1987 08:31:24-PST
From   : D-ROGERS@EDWARDS-2060.ARPA
Subject: I/O ASSIGNMENTS

       Sorry to post this on the whole net, but i couldn't come up
with a valid return address from the original msg.
>Sender: "John A. Wright" <SAC.HQSAC-DOCT@E.ISI.EDU>
>Subject:   CP/M Devices

>I am somewhat confused.  I have downloaded two terminal pgms for my
>Osborn I that are supposed to run off the serial port.  Neither does.

>In my reading, I have come across the explanation of the "STAT"
>command which allows me to assign any physical device to a logical
>device.  My problem is that I can't figure out form the book exactly
>what that means.

>According to the Ref manuel I have the following logical devices:

>  CON: >> Keyboard + screen
>  RDR: >> serial/parallel/ieee  (Can anyone tell me what a "reader" is)
>  PUN: >>   "        "      "   (Can anyone tell me what a "punch" is)
>  LST: >>   "        "      "

Here is an explanation of your physical devices:

  TTY: a hardcopy terminal, (originally a KSR-33) 
  CRT: video terminal (CONsole)
  BAT: the BATCH control file
  UC1: Secondary COMM port
  PTR: COMM port IN (also the paper tape "reader" of the KSR-33)
  UR1: supplemental i/o IN
  UR2:         "
  PTP: COMM port OUT (also the paper tape "punch" of the KSR-33)
  UP1: supplemental i/o OUT
  UP2:          "
  LPT: the primary LIST device, (LST:), a printer, usually serial.
  UL1: ?

>Does anyone have a simple explanation for all this, or even a not so
>simple one would be a help.

Stat allows you to tie a logical name eg: (CON:) to a *particular* physical
device eg: (TTY:) so that standard CP/M system calls will access the
correct port on YOUR system.

an example might be:   A>stat dev:<ret>
the system might return:
                       CON: is CRT:                     
                       LST: is LPT:
to change the assignments:
                       A>stat logdev:=physdev:<ret>
such changes are TEMPORARY, a ^C will restore defaults.  But this will
allow you to find which devices will run your prog's and you can sysgen
the changes if need be (or modify the prog's to use the correct calls
for your devices).
       Hope this is what you needed.           [dale]

       "...of course my opinion differs from 'most everyone else!  If it
 were the same, i'd probably have to change it, lest i remain in error."