LOWMEM.DOC FOR LOWMEM.COM WRITTEN BY LARRY KRAEMER 9/15/83 THIS PROGRAM WILL TEST ALL MEMORY FROM 0000H THRU 4100H. IT DOES A VERY EXTENSIVE TEST ON ALL MEMORY LOCATIONS, AND ALSO TESTS THE LOCATIONS NEXT TO THE PRIMARY TEST LOCATION. THIS PROGRAM SHOULD BE RUN FOR SEVERAL HOURS SO THAT IT WILL HAVE SEVERAL PASSES THRU THE MEMORY. PROGRAM OVERVIEW FOLLOWS: THIS PROGRAM LOADS LOW, THEN MOVES ITSELF HIGH. AFTER CLEARING THE SCREEN IT DISPLAYS THE INITIAL MESSAGES. NEXT THE MEMORY TEST BEGINS WITH LOCATION 0001H THRU 4100H. THE SCREEN WILL SHOW A BAD MEMORY LOCATION IN THE UPPER LEFT CORNER. IF NO ERRORS OCCUR THERE WILL BE NO HEX ADDRESS IN THE UPPER LEFT OF THE SCREEN. THE LOWER RIGHT OF THE SCREEN DISPLAYS AN * WHICH WILL ALTERNATE WITH A SPACE AS THE PROGRAM COMPLETES ONE PASS THRU MEMORY. THE SCREEN WILL DISPLAY AN * ON PASSES 1,3,5,7 ETC. AND A SPACE ON PASSES 2,4,6 ETC. THERE IS A DISPLAY OF THE AREA BEING TESTED IN THE CENTER OF THE SCREEN. THE DISPLAY IS IN ASCII, AND THE LEFT BYTE IS THE LSB (LEAST SIGNIFICANT BYTE) WITH THE RIGHT BYTE THE MSB. FOR EXAMPLE THE DISPLAY WILL SHOW FROM 00H THRU FFH IN THE LSB WHILE THE RIGHT BYTE WILL BE THE PAGE NUMBER FROM 00H THRU FFH. THE FORMAT ON THE SCREEN WILL BE BYTE/PAGE. WITH 64K OF MEMORY THERE ARE 00H THRU FFH BYTES/00H THRU FFH PAGES. LET THIS PROGRAM RUN THRU SEVERAL PASSES, AND IF A BIT CHANGES THE HEX ADDRESS WILL BE DISPLAYED ON THE SCREEN. LOAD THIS ADDRESS IN BITCHK, AND TEST TO SEE WHICH BIT IS BAD. THEN THE BAD CHIP CAN BE REPLACED. GOOD LUCK AND HOPEFULLY YOU WILL NEVER NEED THIS DIAGNOSTIC. LARRY KRAEMER R 2 BOX 190 JACKSON, MO. 63755 NOTE: This MAC file was assembled on my Radio Shack Model 1 so, if you want to assemble it with MAC then add the necessary options/flags/switches to make it work. I just got my Macro assembler and have not converted all files yet.