Date   : Tue, 29 Dec 1987 09:28:34 est
From   : marwood@dmc-crc.arpa (G. J. Marwood)
Subject: MEX1.65 Character Loss

 
The CP/M system that I use is an Apple ][+ and PCPI Applicard.  While 
developing a new overlay and PCPI driver using interrupts, to avoid the 
usual character loss at high baud rates, I have come across a problem 
which seems to afflict the Apple/Applicard even without interrupts and at 
1200 baud.  At this baud rate, I experience no character loss on screen 
during normal operation.  However, if I invoke a capture file, I do experience
character loss at the place where the capture buffer is being written to disk 
(in this case it is the Applicard add-on Ramdisk).  THis loss occurs both on 
screen and in the captured file and, typically may be half a dozen or so 
characters.  It seems that this bug has always been present in the MEX software
that I have used, though I had not noticed it because I don't usually capture
files as large as the capture buffer (16-17K).  Another local user has done a 
similar test with MEX1.65B and a non-Apple CP/M machine and the loss does not 
occur.  It does not, therefore, seem to be a basic problem with MEX.  If any 
Apple/Applicard user has noticed this before and has any clues about solving 
the problem, I would be interested to know.

                                              Gordon Marwood