K538915@CZHRZU1A.BITNET (08/11/87)
I found a very interesting article in a special edition of the german
computer magazin ST Computer (ST-Computer Sonderheft Nr. 2), the article
is titled 'TOS intern' and is written by someone who has 'decompiled'
GEMDOS. It mainly explains how GEMDOS memory-management (the
GEMDOS internal memory too!) and program loading (Pexec) works, it explains
- why Malloc normally doesn't reuse memory blocks
which are cut of from the the largest block of
memory (the author provides a patch to fix this!),
- why desk-accessories shouldn't Malloc or load
resource files (this isn't a bug in GEMDOS),
- why running out of internal memory (40 folder feature)
normally doesn't cause an error message (the desktop
ignores the error message from GEMDOS).
Besides the patch for Malloc, there are patches for some minor bugs:
- Mshrink doesn't test for enough internal memory,
- Size of relocate data is limited to 32 kB,
- Program file not closed if an error occurs during
loading,
(all the patches are for ROM & RAM TOS (if you've still got a copy
of RAM TOS you can try it out on that before you start burning EPROM's:-)),
possibly they'll only work for the german version).
If you can read german and are interested in how GEMDOS ticks, I can
recomend buying a copy of the magazin.
A question to ATARI: how many of these things are fixed in the
'Blitter-ROM' ? All of these bugs are trivial to fix (the patches are
between 3 and 80 bytes long....).
Simon Poole
K538915@CZHRZU1A.BITNET
Disclaimer: I've got nothing to do with 'ST-Computer', except that
they gave me a copy of their magazin in exchange for a
copy of UniTerm.