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1541 circuit theory

[mICROPROCESSOR cONTROL SCHEMATIC]

mICROPROCESSOR cONTROL OF ram AND rom

ub3 AND ub4 ARE 8192 X 8 BIT roms THAT STORE THE dISK oPERATING sYSTEM (dos). ub3 RESIDES AT MEMORY LOCATIONS $c000-$dfff. ub4 RESIDES AT MEMORY LOCATIONS $e000-$ffff. uc5 AND uc6 DECODES THE ADDRESSES OUTPUT FROM THE MICROPROCESSOR WHEN SELECTING THESE roms.

ub2 IS A 2048 X 8 BIT ram. ub2 RESIDES AT MEMORY LOCATIONS $0000-$07ff. tHIS MEMORY IS USED FOR PROCESSOR STACK OPERATIONS, GENERAL PROCESSOR HOUSEKEEPING, USE PROGRAM STORAGE, AND 4 TEMPORARY BUFFER AREAS. uc5, uc6 AND uc7 DECODE THE ADDRESSES OUTPUT FROM THE PROCESSOR WHEN SELECTING ram.

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tHIS PAGE HAS BEEN CREATED BY sAMI rAUTIAINEN.
lAST UPDATED aPRIL 18, 1998.
rEAD THE SMALL PRINT.