mat@zeus.opt-sci.arizona.edu (Mat Watson) (10/24/90)
I just had my old 8086 system upgraded to a baby 80286 system
at a local computer store. Unfortunately there's a strange
problem concerning my modem and serial I/O cards that
neither the vendor or I can figure out. With either the modem
or the serial I/O card installed by itself each of the cards
works fine. Howerver, if both are installed at the same time
neither of them works correctly. This included the system
failing to recognize one of the cards altogether even after
we had checked to make *sure* that each of the cards had a
unique COM/IRQ number pair compatible with the software on
my system. Finally we found an I/O card that along with my
modem allowed the system to recognize both with the correct
IRQ/COM numbers. Still the cards failed to operate correctly.
What could possibly be wrong?
Configuration:
System Board - 286LX-A , VLSI chip set, no manufacturer name in manual.
I/O Board - PE-508, 2 serial, 1 parallel, and 1 game port,
again no manufacturer name in manual. COM1 IRQ4
Modem Board - 2400B/2 by Prometheus. COM2 IRQ3
Any help will be appreciated.
--Mat mat@zeus.opt-sci.arizona.edumat@zeus.opt-sci.arizona.edu (Mat Watson) (10/25/90)
Oops! I made a mistake on my earlier posting. Here's the
corrected configuration:
Configuration:
System Board - 286LX-A , VLSI chip set, no manufacturer name in manual.
I/O Board - PE-508, 1 serial, 1 parallel, and 1 game port,
/
correction: (was 2)_____/
again no manufacturer name in manual. COM1 IRQ4
Modem Board - 2400B/2 by Prometheus. COM2 IRQ3
Any help will be appreciated.
--Mat mat@zeus.opt-sci.arizona.edugordon@vaxeline.COM (*Hobbit*) (10/30/90)
In article <MAT.90Oct23221635@zeus.organpipe.cs.arizona.edu> mat@zeus.opt-sci.arizona.edu (Mat Watson) writes: >With either the modem >or the serial I/O card installed by itself each of the cards >works fine. Howerver, if both are installed at the same time >neither of them works correctly. This included the system >failing to recognize one of the cards altogether even after >we had checked to make *sure* that each of the cards had a >unique COM/IRQ number pair compatible with the software on >my system. > >Any help will be appreciated. You never make any mention of I/O addresses. You must verify that the cards do not conflict in I/O address space. port interrupt I/O address space COM1 IRQ4 3F8-3FF COM2 IRQ3 2F8-2FF There should be jumpers on the boards which allow you to set the I/O address. To find out which address a board is trying to use, boot your PC with only one board installed and use DEBUG to examine address 0040:0000. There you will find the swapped value of the I/O addr of the serial port: C:\> debug -d 40:0 0040:0000 F8 03 00 00 00 00 00 00-BC 03 78 03 00 00 00 00 -q C:\> You will know that your system is configured correctly when the values at location 0040:0000 look something like this: -d 40:0 0040:0000 F8 03 F8 02 00 00 00 00-BC 03 78 03 00 00 00 00 My guess is that the two boards are both configured to use 3F8 and the BIOS routines in the POST cannot see both boards. Subsequent operations performed on the I/O address will induce colliding responses from the boards with unpredicatable results. See the IBM Tech Ref section on I/O controllers for more info. Hope this helps -- ========================================================================== Gordon Lee Member, Technical Staff FTP Software, Inc. (617) 246-0900 x287
david@csource.oz.au (david nugent) (11/06/90)
In <1207@vaxeline.COM> gordon@vaxeline.COM (*Hobbit*) writes: >C:\> debug >-d 40:0 >0040:0000 F8 03 00 00 00 00 00 00-BC 03 78 03 00 00 00 00 >-q >C:\> >You will know that your system is configured correctly when the values >at location 0040:0000 look something like this: >-d 40:0 >0040:0000 F8 03 F8 02 00 00 00 00-BC 03 78 03 00 00 00 00 Unfortunately, this doesn't work on most systems if you install a 16550A on the port. Most BIOS's seem to fail the chip in their fairly simple diagnostic, so very often you need to run some "corrective" software which fills both in this area in BIOS correctly and updates the hardware bits which are returned from INT 11H. -- Fidonet: 3:632/348 SIGnet: 28:4100/1 Imex: 90:833/387 Data: +61-3-885-7864 Voice: +61-3-826-6711 Internet/ACSnet: david@csource.oz.au Uucp: ..!uunet!munnari!csource!david