!pr1
A Solution to Overlapping DOS Patches.............Paul Lewis
                                           Fairfax, Virginia

I have recently resolved a compatibility problem between two desirable sets of DOS 3.3 patches:  the RAMdisk of the 192K Neptune extended memory card, and the DOS Dater that comes with Applied Engineering's Timemaster II.  It seems they both want to put patches into the same "unused" spaces inside DOS.

After examining the two patches carefully, I found out which parts of the patches were overlapping.  Being unable to find a truly unused area inside DOS, I used the technique on page 7.3 of "Beneath Apple DOS" of placing routines in the "safe" area between DOS and its buffers.  This seems to work fine.  [ Until you try to run some other program that does the same thing, like PLE... (editor) ]

The file DATER.OBJ0 contains the DOS.DATER patch that I use.  I noticed that the patch could be placed anywhere, since there are no internal references.  Using an Applesoft program (part of my HELLO), I move the DOS buffers down far enough to fit this code in, and then BLOAD the patches.

!lm+5
100 PRINT CHR$(4)"BRUN AUTO NEPTUNE"
110 PRINT "PSEUDO DISK INSTALLED"
120 POKE 40192,128 : REM Lower the buffers
130 PRINT CHR$(4)"MAXFILES 3"
140 PRINT "BUFFERS MOVED"
150 PRINT CHR$(4)"BLOAD DATER.OBJ0,A$9CD0"
160 POKE 45571,15 :REM Patch file name length
170 POKE 42883,14
180 POKE 44085,208 :REM Hook DOS to the DATER code
190 POKE 44086,156                   
200 PRINT "DOS DATER INSTALLED"
!lm-5
