Path: utzoo!attcan!uunet!cs.utexas.edu!csd4.csd.uwm.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!dgc.mceo.dg.COM!Bruce_Kahn
From: Bruce_Kahn@dgc.mceo.dg.COM
Newsgroups: comp.sys.apple
Subject: Code Fragment question
Message-ID: <8908151859.AY00046@adam.DG.COM>
Date: 15 Aug 89 17:59:46 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: KAHN%void.mceo.dg.com@relay.cs.net
Organization: The Internet
Lines: 16

CEO summary:
  I was taking a look at possibly porting MAC.TRANS.GS to C and 
adding a nicer interface to it but I have to "port" the ML routine as 
well.  I cant decypher one part:
  JSR     $C50A
  LDX     #00
  BCC     1:
  TAX
1: STX    338
  The routine saves the memory region 42.47, loads it with values, 
makes the call, and then restores the region.  I cant find any 
reference to it any any of my manuals.  Can someone help me with what 
this code fragment does and what the values at 42.47 are used for (my 
map of zero page does not describe them)?  I would like to know what 
C50A does and what params it takes.  
                                   Bruce (KAHN@ADAM.DG.COM)