Memc03 - Tandy Color Computer 3 TRS-80 Diagnostic Manual

TECHNICIAN SERIES
DIAGNOSTIC SERIES
------------- TANDY COMPUTER PRODUCTS -------------
- MEMCOJ/BIN -
"MEMC03" is a diagnostic program which allows testing all of the RAM of the
Color Computer-3 (128k or 512k). The Memory Management (MMU) section of the
Advanced Color Video Chip (ACVC) allows the 6809 processor to access memory
outside of the normal 64k address range.
To load this memory diagnostic: type LOAD "MEMC03/BIN" and <ENTER).
To execute this diagnostic: type EXEC and press <ENTER>.
This diagnostic begins by showing a menu of selections available:
(1)
=
PASS MODE (Single/Continuous),
(2) • RAM
TEST,
<3> • Exit to Basic.
When entering the menu, the MMU is tested to see
memory outside the normal 64k addressing scheme.
properly, then the menu will display "MMU Good".
properly, the menu will display "MMU Bad" (Memory
ACVC chip may be faulty).
whether it will access
If the MMU is operating
If the MMU is not operating
or the MMU section of the
Press <l> to toggle the pass mode and set it as single or continuous. This
flags the ram test whether it should test all memory once, or continuously.
Press <2> to invoke the memory test. The screen displays the pass number,
the test mode (write or verify), and the memory range being tested, with an
area on the video reserved for any errors that may occur during the memory
test. The memory range being tested, is displayed as two five digit
hexadecimal numbers which represent the beginning and ending addresses of the
memory range currently being tested.
The process of testing an eight kilobyte range (2000H) of memory involves:
Writing a modified address pattern to all segments of this memory range, then
verifying it from the minimum valid segment to segment seven, and displaying
any error messages. The minimum valid segment, is the segment where the
memory begins (128k machines= Segment-7, 512k machines= Segment-0).
Memory is tested in eight kilobyte (2000H) blocks as noted above, until the
end of memory (this is a pass). If the test is in the single pass mode, it
will exit to the menu. If in the continuous mode, the pass number is
incremented by one and all memory is tested again.
COLOR COMPUTER-3 DIAGNOSTICS
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