>programs, but not all software. Where is the
>start address located in all the different sized
>binaries? What are the different sizes of binaries
>available? 2048, 4096, 6144, 8448? Is it the
>last few bytes of a 4096 byte image? Should
>a 2048 byte .bin be turned into a 4096 byte
>image by sending it twice, like $f000-$f7ff and
>$f800-$ffff are mirrors of each other?
The start address is usually stored three times at the end of the BIN
file, since this is also the end of the 6507 address range, where the
reset and interrupt vectors have to be. This is true for most 2kb, 4kb
and 6kb files. 8448 byte files are a special emulator format. They
contain the three 2kb Supercharger memory banks, 2kb of filler data and
256 bytes of header information.
The 256 bytes block at the end of the 8448 bytes files starts with the
eight header bytes, that you need to send to the SC. Then it could
contain the header information for each of the 256 bytes blocks to be
send to the SC, but most programmers don't include that.
Some of the older dumped 2kb carts need to be doubled to work on the SC.
Newer SC specific 2kb files just need to be loaded to the right memory
bank. Therefore it is important, that you set the control byte and the
header bytes for the 256 bytes blocks accordingly to the file size.
Since not all programs follow theese conventions, you should make it
possible for the user of your C64->SC program to enter all header
information, like start address, control byte or multiload byte, by
hand.
Ciao, Eckhard Stolberg
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