Purpose: Load RAM from device
Call address: $FFD5 (hex) 65493 (decimal)
Communication registers:A, X, Y
Preparatory routines: SETLFS, SETNAM
Error returns: 0,4,5,8,9, READST
Stack requirements: None
Registers affected: A, X, Y
Description: This routine LOADs data bytes from any input device di- rectly into the memory of the Commodore 64. It can also be used for a verify operation, comparing data from a device with the data already in memory, while leaving the data stored in RAM unchanged.
The accumulator (.A) must be set to 0 for a LOAD operation, or 1 for a verify, If the input device is OPENed with a secondary address (SA) of 0 the header information from the device is ignored. In this case, the X and Y registers must contain the starting address for the load. If the device is addressed with a secondary address of 1, then the data is loaded into memory starting at the location specified by the header. This routine returns the address of the highest RAM location loaded.
Before this routine can be called, the KERNAL SETLFS, and SETNAM routines must be called.
|NOTE: You can NOT LOAD from the keyboard (0), RS-232 (2), or the screen (3).|
How to Use:
;LOAD A FILE FROM TAPE LDA #DEVICE1 ;SET DEVICE NUMBER LDX #FILENO ;SET LOGICAL FILE NUMBER LDY CMD1 ;SET SECONDARY ADDRESS JSR SETLFS LDA #NAME1-NAME ;LOAD A WITH NUMBER OF ;CHARACTERS IN FILE NAME LDX #<NAME ;LOAD X AND Y WITH ADDRESS OF LDY #>NAME ;FILE NAME JSR SETNAM LDA #0 ;SET FLAG FOR A LOAD LDX #$FF ;ALTERNATE START LDY #$FF JSR LOAD STX VARTAB ;END OF LOAD STY VARTA B+1 JMP START NAME .BYT 'FILE NAME' NAME1 ;