[net.micro.atari16] VT52 emulator locks up serial port

ATARI@UMass.BITNET (08/26/86)

When I accidently hit two keys at the same time on my 1040ST, while
using the VT52 emulator desk accessory, the serial port sometimes locks up.
It will not send and most (but not all) of the time will not receive.  On
occasion, the host computer has continued to send data but my ST would not
send, but on almost all (I would estimate 95% of the time) occasions
both directions lock up.  The system otherwise functions normally.  The
only way to solve the problem is to reboot.
   I have never had this happen with any ST telecommunications program
other than the VT52 emulator, though I have on many occasions sat there
banging away on two keys to try and make it happen.
   It is a repeatable problem with the VT52, however.
   Does anyone know why this happens?  Has anyone else had this problem
or is there something wrong with my machine?  (unlikely, because all
other programs work fine.)  Is there a fix for this, like a new version
of the VT52?
  Thanks...

Mike Cohan   MCOHAN%UMASS.BITNET@WISCVM.ARPA or MCOHAN@UMASS.BITNET
or MCOHAN%UMASS.BITNET@WISCVM.WISC.EDU
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"Indecision is the basis of flexibility."
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don@cs.qmc.ac.uk (Don Beal) (08/28/86)

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In article <860825204410.000018D7.APEG.MA@UMass> ATARI@UMass.BITNET writes:
>When I accidently hit two keys at the same time on my 1040ST, while
>using the VT52 emulator desk accessory, the serial port sometimes locks up.

I found the Atari VT52 emulator (on my 520ST) can lock up.  In my case it
was triggered by RTS/CTS problems.  My own terminal emulator did not lock up
under the same conditions, and printed a warning that the RS232 port was
not ready to transmit data.

I guess the Atari emulator does not do an "bcostat" bios call before doing
the "bconout" call.  No way for a user to fix, but trivial for the writer
of the emulator to fix, at least to the extent of not locking up.  Unjamming
the port may be harder.  I power cycled.

Anyone care to tell me what system call or calls are necessary to reset the
RS232 port?  In my case I found that toggling the RTS/CTS option, or changing
the baud rate, with the "rsconf" xbios call was not sufficient.