Problems with third party hardware add-ons using PC10-III Rev 6 PCB assemblies (also used in PC20-III and Colt), have been traced to the "IOREADY" signal which will tri-state when it is not pulled low by PVC4.
A field fix has not been issued for this problem.
PCB# 312625-01 (marked Rev 6.2) are available for exchanges.
The normal PC warranty will cover the exchange.
Source: Commodore Techtopics 26/5-1.1
The PC10-III, PC20-III and Colt have a mouse port which is used by the Commodore 1352 mouse.
Third party mouse cards used in the expansion slots override the build in mouse driver when the system runs Auto-Config program during the power up sequence.
The Commodore mouse uses interrupt 2, this conflicts with certain third party mouses, such as Logitech, which also use interrupt 2.
A program is available from Service which disables Commodore mouse interrupt and allows the third party mouse to use interrupt 2.
Refer to CTOC section 7 Download, of current on-line issue 25 Techtopics for instructions.
CHGMOUSE - is the program file.
README - file contains information on the program.
Source: Commodore Techtopics 24/5-1.1
A new BIOS ROM, revision 4.38, CBM part number - 318085-05, has been released for the PC10-III, PC20-III, Colt and the Select Edition.
This is considered a running change, and is not covered by warranty. Customers must pay for this upgrade. Dealer billing is $33.00.
The new ROM rev 4.38 adds a new setup feature which emulates the "AT" setup utility. To run the "AT" setup utility, press <Cntrl-Alt-Esc>. The screen resembles the PC40-III setup.
Default configuration is:
BIOS revision 4.38 supports the 5720 IO/mouse controller, and real time clock access - like "AT" systems, clock is set during setup, the setclock utility does not need to be run.
Source: Commodore Techtopics 28/5-2.1
A new BIOS ROM for the PC10-III, PC20-III and Colt is being released. New part number is 318085-02. This is an in-line upgrade and must be purchased by the end user directly through an authorized service center. Installation of this IC must be done by an Commodore authorized technician.
The following summary details changes in BIOS 4.36
Source: Commodore Techtopics 22/5-3.1
The PC10-III, PC20-III and Colt have a built in monitor, in addition to the debug monitor in the operating system.
The Commodore 8088 Monitor may be entered when a error condition is detected on power up tests by pressing the control key in combination with the 'M' key.
You may examine the monitor by leaving the boot disk out of system at power up, a system message will appear on console:
Boot disk failure. Type key to retry
Press Cntrl + M to enter CBM monitor.
System will respond with:
COMMODORE 8088 Monitor
Pre-release Version 2.0
Copyright 1987 Commodore Technology Group
Use ? for help
Responding with a question mark, return, will generate the following monitor options:
Dump [starting addr]
Fill [starting addr] [count] [data]
Goto [addr] [breakpoint1] [breakpoint2]
Input port [byte|word] [port addr]
Output port [byte|word] [port addr] [data]
Move [source addr] [dest addr] [count]
Substitute Memory [address]
Source: Commodore Techtopics 22/5-2.1
|U104, U204, U205, U304||74LS245||901521-46|
|U108, U109, U202, U603||74LS244||901521-03|
|U605, U321..U324||64k x 4 DRAMs 100 ns||390083-04|
|U305..U320||256k x 1 DRAMs 80 ns||390223-05|
|U607||Video Character ROM||318086-01|
Source: Service Manual PC 10-1/10-2/10-III PN-314860-01 March, 1988 © 1988 Commodore Electronics Limited
|Memory Address (Hex)||Contents|
|00 00 00||03 FF FF||640k base RAM|
|04 00 00||09 FF FF|
|0A 00 00||0A FF FF||EGA/VGA video RAM|
|0B 00 00||0B 3F FF||Monochrome video|
|0B 40 00||0B 7F FF||Reserved|
|0B 80 00||0B FF FF||Color video|
|0C 00 00||0C 7F FF||Reserved for EGA BIOS|
|0C 80 00||0C 9F FF||Available|
|0C A0 00||0F 7F FF||Reserved|
|0F 80 00||0F 9F FF||CBM 8088 Monitor|
|0F A0 00||0F BF FF||Hard Drive BIOS|
|0F C0 00||0F FF FF||16k Main BIOS|
Source: Commodore Techtopics 22/5-1.1
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Last update: 26 March 2021