| It's possible, but requires a little hacksperstise (that's "hacker" and
"expertise" lumped into one word, I made it up.)
What you need to do is write a "boot block" on the new disk using RWABS
that has the double-sided numbers for the disk size and configuration,
but the boot information from the single sided, disk, plus a correct
checksum of $1234. I've never actually done this sort of thing. Books
that describe the Atari disk formats (Abacus inside ST disks, for
example) would help you along.
I can generate more details if you need them.
|
| Thanks for your quick answer.
I found a way to do it. For those who will run into this problem too I'll
post the procedure I finally used here.
You need : a diskeditor that allows you to access individual sectors and
modify them
a little program that calculates the correct checksum (or you can
do it by hand: just add wordwise, not by byte!)
do it as follows:
look at the ss disk bootsector: the bytes # $08-$16 (plus/minus
one or two bytes) contain the diskformat information (sectorcount
trackcount etc). Compare them to the values from a ds disk.
now format a ds disk.
read the bootsector from your ss disk, replace this disk by the
ds disk and save the bootsector.
patch the appropriate diskinfo bytes to the values they should
have on a ds disk (you know them from your freshly formatted
ds disk, don't you?)
adjust the last two bytes in this newly created ds bootsector
to give an overall checksum of $1234.
Now you should have a double sided disk with an executable bootsector. Copy
your TOS.IMG (or whatever you want to be loaded at boottime) to it and boot.
---markus---
ps there is a German book 'Scheibenkleister'. It tells you all about disks and
has the whole bunch of demos as on a source disk coming with the book.
There I found a pascal prog that adjusts the checksum!
|