Table of Contents
PSYMON 1.20B
The original Psymon was used on Motorola EXORcisor boards in the 1970s and it loads and runs from FC00 with only the MPU vectors reserved.
INSTRUCTIONS, SOURCE, LICENSE
ASSEMBLER SOURCE
Contains PSYMON120B.s assembly source code and Percom_PSYMON_6809_Monitor.pdf documentation containing the original source code listing.
ASSEMBLING PSYMON
Download or setup William “lostwizard” Astle's LWTools
Example assembly command, assuming the source is saved as PSYMON120B.s
lwasm -9 -f raw --list=PSY120B.txt --symbols=PSY120B-sym.txt -o PSY120B.BIN PSYMON120B.s
This will give you a 1KiB raw binary output file.
For a Motorola S-record format used by some tools:
lwasm -9 -f srec -o PSY120B.srec PSYMON120B.s
For an Intel hexdump format used by some tools:
lwasm -9 -f ihex -o PSY120B.ihex PSYMON120B.s
COCO ARCHIVE CONTRIBUTION
The version I uploaded to the Color Computer Archive contains the original source from the PDF for historical / archival purposes.
I also included additional modified versions for the Color Computer 1, 2, and 3 as well.
COCO MODIFICATIONS
The CoCo1/2 version loads and runs Psymon at $6C00 so its for a 32K CoCo - but could be moved much lower for 16K or 4K. It's probably best to run CLEAR 200,&H6C00 before LOADM so that its protected from BASIC itself.
The CoCo3 version is sneakier - it loads in at $FC0A and uses RAM at $FE69 so that it can be co-resident with Super Extended BASIC without conflict rather than taking away a bit of the BASIC workspace RAM.
Both of these use the POLCAT and CHROUT ROM routines for simplicity as a quick port.
Providing standalone keyboard and screen output console drivers is left as an exercise for the reader.
SEE ALSO
RTS
Return to Tandy Color Computer