RCA CDP18S711 manual CHIP-8Memory Map, CDP1802 Register Use for CHIP-8, Interpreter

36RCA COSMAC VIP Instruction Manual

CHIP-8 Memory Map	CDP1802 Register Use for CHIP-8
	Interpreter
	R0	= DMA pointer (page 0X for display refresh)
	R1	= INTERRUPT routine program counter
	R2	= Stack pointer
	R3	= INTERPRETER subroutine program counter
	R4	= CALL subroutine program counter
	R5	= CHIP-8 instruction program counter
	R6	= VX pointer (R6.1 must not be changed)
	R7	= VY pointer (available for machine-language subroutines)
	R8	= Timers (R8.1 = timer, R8.0 = tone duration)
	R9	= Random number (+1 in INTERRUPT routine)
	RA = I pointer

RB = Display page pointer (RB.1 = 0X)

RC =Available

RD = Available

RE = Available

RF = Available