Re: PET memory maps

From: Ethan Dicks (ethan_dicks_at_yahoo.com)
Date: 2002-01-14 17:43:52

--- Marko_Mäkelä <msmakela@cc.hut.fi> wrote:
> On Sun, 13 Jan 2002, Ethan Dicks wrote:
> 
> > I spent most of my larval-stage learning curve on a BASIC 2.0 PET, so
> > I'm most familiar with it.  I have pored over the stuff on funet to
> > find out what I might be stepping on, but I gave up a while ago until
> > I find some new docs.
> 
> Did you have a look at the prlink source code?  It contains the header
> files petram34.lib, petrom3.lib and petrom4.lib.  Thank Olaf Seibert for
> composing them.

I haven't, but now I will.  The problem comes in that the Infocom engine
takes over the machine and roaches the zero page (in fact, everything below
the start of BASIC).  Something called by $FFD2 is scribbling on a location
that I have assigned and I don't know what it is.  I have traced through
the editor ROM to try and figure it out, but, essentially, 2.0 does not
use as much low storage to print characters to the screen as 4.0 and,
somewhere,
I have assigned a location that I shouldn't have.  Once I find that magic
address, I can reassign the symbol and all should be well (presuming there
are enough unused locations that I _can_ reassign it - the Zork Implementation
Program - ZIP - is a zero-page pig).

-ethan


=====
Visit "The Seventh Continent"
http://penguincentral.com/penguincentral.html

__________________________________________________
Do You Yahoo!?
Send FREE video emails in Yahoo! Mail!
http://promo.yahoo.com/videomail/

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail 2.1.1.