Page 03

C64 Page 3 Vectors & Cassette Buffer

Address	Len	Name	Description	Default
0300	12		BASIC Indirect vector table
030C	4		Storage for registers with BASIC SYS call 1 byte each for A, X, Y & Status in that order
0310	3	USRPOK	Jump instruction for BASIC USR() function Actual JMP instruction so first byte MUST be 0x4C	0x4c
0311	2	USRADD	Address of USR() function This is the address used by USR() when it calls USRPOK
0313	1		Unused
0314	2	CINV	IRQ Interrupt Routine Vector	0xEA31
0316	2	CBNV	BRK Interrupt Routine Vector	0xFE66
0318	2	NMINV	NMI Interrupt Routine Vector	0xFE47
031A			Kernal Indirect Vectors
031A	2	IOPEN	Kernal OPEN Vector	0xFE4A
031C	2	ICLOSE	Kernal close Vector	0xF291
031e	2	ICHKIN	Kernal CHKIN Vector	0xF20E
0320	2	ICKOUT	Kernal CKOUT Vector	0xF250
0322	2	ICLRCH	Kernal CLRCHN Vector	0xF333
0324	2	IBASIN	Kernal CHRIN Vector	0xF157
0326	2	IBSOUT	Kernal CHROUT Vector	0xF1CA
0328	2	ISTOP	Kernal STOP Vector	0xF6ED
032A	2	IGETIN	Kernal GETIN Vector	0xF13E
032C	2	ICLALL	Kernal CLALL Vector	0xF32F
032E	2	USRCMD	User-Defined Command Vector Unused on C64, holdover from the PET.	0xFE66
0330	2	ILOAD	Kernal LOAD Vector	0xF49E
0332	2	ISAVE	Kernal SAVE Vector	0xF5DD
0334	8		Unused, space for 4 user vectors
033C	192	TBUFFR	Cassette I/O Buffer
03FC	4		Unused