8.2. Determination of the length
BASIC program
Length: 13
Number of variables: 0
Checksum: 1544
Purpose: BEYSIKprogrammy gives the length in bytes.
Calling the program:
PRINT USR address
Error Check: No
Comments: none
LISTING machine code
Assembly label number to VVODA147.
LD HL, (23627) 42 75 92
LD DE, (23635) 237 91 83 92
AND A 167
SBC HL, DE 237 82
LD B, H 68
LD C, L 77
RET 201
2
How it works:
In a couple of registers HL loaded address of the variables,
and DE loads the address of BASIC programs. DE is subtracted
from the HL, to get the length of the program.
HL is copied to the BC and the program
returns to BASIC.
