MYDOS 4.51 -- Released June 14, 1989

MYDOS 4.51 restores some of the
"features" of 4.3, including being
written in Atari AMAC syntax (that
is, compatible with MADMAC and my
own A65 assemblers). This seems more
consistent than MAC/65. See the
following list for the changed
code. Like 4.50, it mostly fixes
bugs in features that never worked
right in the past. the changes are
very minor.


Changes from 4.50 to 4.51 --

1.Lock/Unlock work the way they
  used to.  Query is the default.
2.A bug inserted into the program
  load code is corrected (some code
  that has to be resident was moved
  into the DUP overlay area).
3.The code to work around I/O errors
  deleting the program file in most
  BASIC program "starter"s is re-
  inserted (inadvertently removed
  in 4.50).
4.Formatting of disks with bad sec-
  tors is reenabled (with warning).
5.Corrected code to copy DOS.SYS
  from one diskette to another (this
  never really worked before).
6.The RAMdisk configuration code in-
  serted by Bob Puff was retained,
  but the old code (with specifiable
  I/O port) is restored for non-
  Axlon, non-XE compatible RAMdisks.
7.The correction to keep the VTOC
  of other disks from being corrupt-
  ed when I/O errors occurred while
  writing a VTOC was worse than the
  problem (any I/O error, scrambles
  all VTOCs with output files open).
  Perhaps the best fix is to retry
  forever?

Copying DOS.SYS -- we now . . .

1) load the 3 boot sectors into RAM
   from the source disk.
2) copy the actual file, renaming it
   "diamond"OS.SYS on the destina-
   tion disk.
3) write the 3 boot sectors to the
   destination drive (updating the
   sector link mask, link location
   and sector size flag).
4) rename "diamond"OS.SYS to DOS.SYS
   (updating the sector size flag
   and the starting sector number of
   DOS.SYS).


To do (before 1990, at least):

1. Add script (batch file) support.
2. Enable BASIC if no cartridge is
   installed and the [B] command is
   issued. Then, disable BASIC if
   the [L] or [N] commands are
   issued.

Any volunteers?


Enjoy,
Charles Marslett