Re: PET kernal routines

From: Mike Stein <>
Date: Fri, 14 Apr 2017 11:16:53 -0400
Message-ID: <195EF0D0F85748BA8E17F068DBFBD7E1@310e2>
There's also a pretty good memory/ROM map/cross-reference in Raeto West's 'Programming The PET CBM'; chapter 15, starting at p. 391.


----- Original Message ----- 
From: "Paul Schmidt" <>
To: <>
Sent: Thursday, April 13, 2017 7:27 PM
Subject: RE: PET kernal routines

> OK, a couple small improvements: I finally found my old copy of "PET/CBM
> Personal Computer Guide (2nd Ed)" by Osborne. It has a kernel listing, which
> confirmed that $FFD2 is in fact correct for the "WRT" subroutine, but it
> listed nothing for a "CRLF" type kernel routine; so I agree with the comment
> that the other routine at $04F2 most have been part of the TIM which could
> have been loaded in in that range of addresses (the same book lists this as
> 'user memory'). 
> The suggestion to re-create the CRLF by using the kernal's $FFD2 subroutine
> to send a $0D (Return) to the screen was a good one, and my tests proved
> that it works just fine. 
> So I rewrote the little program to replace the JSR to $04F2 with the
> just-tested 'manual' method and it now works as expected.
> Thanks to all who responded.
> -----Original Message-----
> From:
> [] On Behalf Of smf
> Sent: Thursday, April 13, 2017 1:49 PM
> To:
> Subject: Re: PET kernal routines
> It looks like 04F2 is part of the cassette loaded TIM, while FFD2 is in the
> kernal rom.
> If you don't have the routine in the version of TIM you have then something
> like this might do it:
> 04F2:
> LDA #$0d
> You could of course put it wherever you want. You might need to call
> FFD2 with $0a as well, but I have a feeling that $0d was enough.
> On 13/04/2017 14:04, Paul Schmidt wrote:
>> ogram. The Upgrade ROM
>> version of the PET memory map shows that area of memory being unused 
>> and available for RAM expansion. And it seems odd that for a 'tiny' 
>> monitor program, two of its internal routines would be so widely 
>> spaced in memory at
>> $04F2 and $FFD2.
>       Message was sent through the cbm-hackers mailing list
>       Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list
Received on 2017-04-14 16:00:03

Archive generated by hypermail 2.2.0.