[comp.sys.apple2] ProDOS Buffer Problem

magras@cpsin2.cps.msu.edu (Jean C Magras) (09/14/90)

Hi Fellow Apple 2 Lovers!
  I'm having a ProDOS problem  with the FREe BUFfeR routine pointed to by the $BEF8
vector in the Basic System Global page ($BE00-$BEFF). This routine manipulates the
following zero page pointers:
                $67/$68 : start of applesoft program ($801 usually)
                $69/$6a : bottom of simple variables ($803   "    )
                $6b/$6c : bottom of array variables  ($803   "    ) 
	        $6d/$6e : bottom of free space       ($803   "    )
                $6f/$70 : bottom of strings          ($803   "    ) 
		$73/$74 : Hi usable space for variables+1 ($c000)


This routine trashes my program (about $b00 and beyond) which runs from $800 - $2000
when FREBUFR is called. I have attempted to get the $67-$70 crowd to point to $200x
but when this is done GETBUFR ($bef5) reports "NO BUFFERS AVAILABLE". Sandy 
Mossberg's September 1985 article in Nibble on these 2 routines offers little help.

HELP!!!!

Thanx in Advance!
J.C. 

           "The first half of our lives is ruined by our parents and the
           second half by our children." Clarence Darrow