[Openmsx-bugs] [ openmsx-Bugs-3011350 ] RS-232 emulation uses an excessive amount of CPU time

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Bugs item #3011350, was opened at 2010-06-04 00:15
Message generated for change (Comment added) made by sd-snatcher
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Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: FRS (sd-snatcher)
Assigned to: Nobody/Anonymous (nobody)
Summary: RS-232 emulation uses an excessive amount of CPU time

Initial Comment:
The RS-232 emulation isn't working. No send chars appear on the output file, and nothing from the input file is received.

Testbed: openMSX-0.8.0-11467 on Mac OS X v10.5.8

Steps to reproduce the problem:

1) run openmsx -machine Panasonic_FS-A1WSX -ext rs232
2) On the openMSX console, type:
2.1) set rs232-outputfilename /tmp/rs232msx.out
3) On MSX-BASIC, type:
3.1) CALL COMINI("8N1NNNNN",9600)
3.2) CALL COMTERM
4) Now type some text on the MSX terminal. It doesn't matter what you type, it never goes to the /tmp/rs232msx.out file

The same applies for the rs232-input file.


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>Comment By: FRS (sd-snatcher)
Date: 2010-06-04 21:41

Message:
Confirmed: plugging the tester makes it work on Mac OS X too, but the CPU
usage also skyrockets and the emulator freezes on exit.

Please document the requirement for the "plug rs232-tester" on the
manual.

I noticed another problem: The rs232.rom required by openMSX currently is
a very earlier version (seems to be v1.00) of the RS-232 BIOS that
contained an annoying bug: a CALL 0217h at the address 4590h, when it
should contain a CALL CALSLT. This has the consequence that this old BIOS
always freezes when it's INIT function is run on MSX2 or higher machines.

Please choose a newer version of the BIOS, like v1.06 or preferably the
v2.00. I'm not sure, but probably the ASCII MSX RS-232C interface has one
of those newer BIOS.


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Comment By: Manuel Bilderbeek (manuelbi)
Date: 2010-06-04 14:16

Message:
I plugged the tester and then it works. But it is weird that openMSX starts
using a LOT of CPU time as soon as the tester is plugged in. Even when
using plain files as input and output. Updating bug report for this.

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Comment By: Wouter Vermaelen (m9710797)
Date: 2010-06-04 04:42

Message:
Did you plug in the rs232-tester? In the console type:
   plug msx-rs232 rs232-tester
Does this fix it? (I can't easily test today.)

I agree this can be confusing/annoying, especially because we currently
only have one rs232 pluggable that fits in the rs232 connector.

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Comment By: Patrick van Arkel (vampier)
Date: 2010-06-04 02:07

Message:
I never used this feature (I knew it existed but never looked into it)

I just started a machine with rs232 extentions loaded (see FRS post) and
typed the commands he typed (including the openMSX console commands)

No file was even created so nothing was written.

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