Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!m2c!wpi!dseah
From: dseah@wpi.wpi.edu (David I Seah)
Newsgroups: comp.sys.apple
Subject: Re: [HELP NEEDED]:  Sending DOS commands after changing modes...
Message-ID: <3252@wpi.wpi.edu>
Date: 15 Jul 89 17:12:34 GMT
References: <20399@cup.portal.com>
Reply-To: dseah@wpi.wpi.edu (David I Seah)
Organization: Worcester Polytechnic Institute, Worcester, MA. USA
Lines: 35

In article <20399@cup.portal.com> Sirald@cup.portal.com (Andrew Lionel Dalrymple) writes:
[STUFF DELETED]
>In  this case, any of the four states doesn't appear to mat-
>ter.  All  that matters is that I moved from 40col to 80col,
>and  the program some how has blocked DOS access.  Even if I
>put  the  'RECONNECT DOS 3.3'  call (40383) into the program
>right  before  the  BRUN  command, the call quitely ends the
>programs  run.
> 
>        I  would be most appreciative if someone has an idea
>as  to  why  CTRL-D commands are ignored, but RUN, LIST, and
>the  others  are  intact.

I almost *always* make this mistake every time I turn on the 80 column mode. 
You have to turn on the 80 column card with a PRINT CHR$(4)"PR#3", not just
"PR#3".  The PR#n command gives control to slot n, which also ends up taking
away DOS's control of the system.  DOS monitors character input and output
from the "console" (slot 0) consisting of textscreen & keyboard.  By issuing
the PR#3 command, you change I/O "hooks" that DOS has set to intercept and
monitor the world, and DOS gets disconnected.  Since people like to use slots,
DOS can "fake" the PR#n and IN#n Applesoft commands while keeping control of
the console itself.  Incidentally, the term "console" here is probably only
valid for the DOS 3.3 / Applesoft environment. 

So just change lines 1500,1600,1700,and 1800
example:

 1500  PR# 3:X =  PEEK (49189): PRINT  CHR$ (15): HOME : PRINT : PRINT 

	becomes ...

 1500 PRINT CHR$(4)"PR#3":X=PEEK(49189):PRINT CHR$(15):HOME:PRINT:PRINT
      ^^^^^^^^^^^^^^^^^^^
Dave Seah | O M N I D Y N E  S Y S T E M S - M |   Internet: dseah@wpi.wpi.edu 
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