Absolute loader record format John Wilson 07/17/1995 .word 1 ;start of record .word bc ;byte count .word addr ;load address .rept .byte x ;data byte(s) .endr .byte chksum ;checksum I put ".word" because that's how to interpret those fields, but there's no need to pad to an even boundary between records. The byte count includes all bytes from the ".word 1" to the end of the data field, but does not include the checksum; it must be >=6 because that's how long the header is. The final record of the tape (or file) has a byte count of exactly 6, and the address field specifies the start address, or an odd number to indicate that the module should not be started. The checksum is the two's complement of all preceding bytes starting at the ".word 1", so that the 8-bit sum of all bytes of the record including the checksum byte, is 000.