[Coco] CoCo 3 POKEs to go to "CoCo 1/2" mode?

[Arthur Flexser]

Perhaps they obtained permission from Microsoft to make specific and very very minor changes to the original ROM code.

I think the overlaying of patches was not done solely for copyright reasons.  The scheme resulted in an excellent compatibility with prior software.

Art
________________________________
From: Arthur Flexser <flexser at fiu.edu>
Sent: Sunday, January 29, 2023 9:02 PM
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Subject: Re: [Coco] CoCo 3 POKEs to go to "CoCo 1/2" mode?

My best recollection is that the CoCo 3 internal ROM is 32K, which was a lot more than they actually needed.  They used 6K of the spare space for the 3 stooges graphic, which they didn't even need to compress.

Art
________________________________
From: Coco <coco-bounces at maltedmedia.com> on behalf of Allen Huffman via Coco <coco at maltedmedia.com>
Sent: Sunday, January 29, 2023 8:57 PM
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Cc: Allen Huffman <alsplace at pobox.com>
Subject: Re: [Coco] CoCo 3 POKEs to go to "CoCo 1/2" mode?

Note: This message originated from outside the FIU Faculty/Staff email system.


> On Jan 29, 2023, at 7:50 PM, Arthur Flexser via Coco <coco at maltedmedia.com> wrote:
>
> No, there were a couple of things that got modified in the Microware CoCo 3 changes that were done to the ROMs, not patched in as RAM overlays.  The main thing was changing DLOAD in ROM to make it do a cold start.


Interesting. I thought I had read that they were not allowed to touch the original ROMs, so they had to just overlay patches on startup. Interesting. How big is the CoCo 3 BASIC ROM?

                — A
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