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    Names: »TRACER.DOC«

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	****************************
	*** TRACER DOCUMENTATION ***
	****************************


	THE TRACER PROGRAM IS A UTILITY TO TRACE THE EXECUTION
OF AN 8080 OR Z80 PROGRAM. IT IS WRITTEN USING Z80 OP-CODES SO
IT MUST BE EXECUTED ON A Z80 SYSTEM. AS WRITTEN IT CAN BE
ASSEMBLED TO RUN ANYWHERE IN MEMORY BUT MUST BE IN R/W MEMORY
BECAUSE IT USES SOME SELF MODIFYING CODE. THE TARGET PROGRAM
MUST ALSO BE IN R/W MEMORY BECAUSE THE TRACER USES RESTARTS
(RST6) WHICH IT MOVES THROUGH THE TARGET PROGRAM.
	THE TRACER AND TARGET PROGRAM MUST BE LOADED INTO
MEMORY, THEN ENTER THE TRACER 'INIT' ROUTINE. THE FIRST PROMPT
ASKS FOR THE ADDRESS WHERE YOU WANT TO START DISPLAYING TRACER
INFORMATION. IT MUST BE AN ADDRESS CONTAINING THE FIRST BYTE
OF AN OPCODE. THE SECOND PROMPT ASKS FOR THE ADDRESS WHERE YOU
WISH TO START EXECUTING THE TARGET PROGRAM. THE INPUT ADRESSES
SHOULD BE IN HEX FOLLOWED BY A CARRIAGE RETURN. IF A MISTAKE IS
MADE IN ENTERING, JUST TYPE THE CORRECT ADDRESS AFTER THE
MISTAKE. TRACER TAKE THE LAST FOUR CHARACTERS TYPED. AFTER THE
SECOND ADDRESS IS TYPED TRACER JUMPS TO THE TARGET PROGRAM AT
THE SPECIFIED ADDRESS AND BEGINS EXCUTING. OPON ENCOUNTERING
THE RESTART (RST6) IT WILL:
	1.DISPLAY THE CONTENTS OF THE REGISTERS
	2.REPLACE THE BYTE DISPLACED BY THE BREAKPOINT
	3.CALCULATE THE NEXT OPCODE TO BE EXECUTED
	4.INSTALL A RESTART AT THE NEXT LOCATION
	5.REENTER TARGET PROGRAM AT THE LAST BREAKPOINT

	TO PAUSE THE TRACER WHILE IT IS RUNNING YOU PRESS
THE 'ESCAPE' (1BH) KEY. A 'TRACER>' PROMPT SHOULD APPEAR.
A SECOND 'ESCAPE' CONTINUES ON WITH THE TRACE. TO STOP THE
TRACE IN PROGRESS FIRST GET THE TRACE PROMPT BY PRESSING THE
'ESCAPE KEY. THEN PRESS THE 'X' KEY. TRACER WILL RESTORE THE
DISPLACED OPCODE THEN ENTER THE INPUT MODE AGAIN.«eof»