In Search Of . . .
by Stephen Reed
The 1541 Disk Drive from Commodore is a complete computer all by itself! This is why no Disk Operating System is required to use it as with most other microcomputers.
The 1541 Micro is complete with its own 6502 processor, an operating system in ROM, and internal RAM for data storage.
It is for this reason the use of the drive is so rigid. There is very little flexibility in the system for doing things not originally planned.
As you know by now, to load a BASIC program from disk the command is: LOAD" Filespec",8
And the command for loading a machine language program into memory is: LOAD" Filespec", 8,1
There is, however, no way to ask the disk drive directly where in memory a program is going to load. This is an important thing to know so that separate programs will not conflict in RAM. This brings us to Addressit, a reasonably short utility which will interrogate a program file and then tell you where in memory it will load.
F$ = Filespec
A$ = ISB Input of Load Address String
B$ = MSB Input of Load Address String
A = LSB of Load Address
B = MSB of Load Address
D = Load Address in Decimal
T = Powers of 16 Counter
H$ = Load Address in Hexadecimal