Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!ames!amdahl!pyramid!prls!philabs!micomvax!ray
From: ray@micomvax.UUCP (Ray Dunn)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Remote Control of IBM PC
Keywords: IBM PC
Message-ID: <1340@micomvax.UUCP>
Date: 25 Oct 88 18:56:55 GMT
References: <757@dinl.mmc.UUCP> <[75.1]karl@ddsw1.comp.ibmpc>
Reply-To: ray@micomvax.UUCP (Ray Dunn)
Organization: Philips Electronics Ltd. (TDS - Montreal) St. Laurent QC, Canada
Lines: 33

In article <[75.1]karl@ddsw1.comp.ibmpc> karl@ddsw1.MCS.COM ([Karl Denninger]) writes:
 >With regards to "remote control":
 >
 >You can do it for free by typing "CTTY COMx:".  After executing this
 >command, your console is redirected to the serial port named.
 >
 >Note that to get back to the normal console, you can execute a CTTY
 >command with no argument, or reboot.  Also -- programs which do direct
 >screen & keyboard I/O (ie: don't use the BIOS calls), or anything
 >which tries to go into graphics mode won't work.

Should say "which don't use the *DOS* calls".

Only DOS calls can be redirected (e.g. INT 21).  BIOS calls (e.g. INT 10)
cannot.

There is *no* support for display and keyboard redirection in the BIOS.

CTTY is of limited value because of the very common useage of direct display
output for text, and, of course, all graphics output is direct.  Even BASIC
doesn't go through DOS, and ansi.sys almost certainly doesn't get invoked if
loaded (haven't tried it).

Unfortunately (or perhaps naturally, because of the PC's architecture) there
is no current satisfactory general solution to a "remote" control terminal.

There is perhaps a niche hardware product opportunity here, but it probably
is only relevant in a pure alpha-numeric mode, a minority market.
-- 
Ray Dunn.                      |   UUCP: ..!philabs!micomvax!ray
Philips Electronics Ltd.       |   TEL : (514) 744-8200   Ext: 2347
600 Dr Frederik Philips Blvd   |   FAX : (514) 744-6455
St Laurent. Quebec.  H4M 2S9   |   TLX : 05-824090