[Coco] Re: 64K Mode

Robert Gault robert.gault at worldnet.att.net
Wed Jan 14 15:58:22 EST 2004


John Collyer wrote:
> That's true, but it also works on a coco3.  Try it.
> Run SuperPatch EDTASM+ on a coco3 emulator
> and see if it don't work.  I'll bet it does.
> 
> John Collyer
> 
> ----- Original Message ----- 
> From: <jdaggett at gate.net>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Wednesday, January 14, 2004 12:57 PM
> Subject: Re: [Coco] Re: 64K Mode
> 

Guys guys, you can't win debates when both sides don't understand the 
terms of the contest!

What does SuperPatch do with memory? What is meant by "page mode?

1) SuperPatch by Roger Schrag, Rainbow, 1983, flips back and forth 
between 64K RAM and 32K lower RAM, 32K upper ROM as needed for disk I/O. 
It does not keep ROM constant and swap between banks of lower 32K RAM.

2) Page mode in this discussion refers to keeping 32K upper ROM and 
flipping between 2 banks of 32K RAM in lower memory.

3) The Coco1 & 2 have the page select defined at $FFD4-$FFD5. Poke $FFD4 
get page0, poke $FFD5 get page1. The Coco3 does not have this latch 
listed in the service manual and it probably does not work.

What you two (Daggett / Collyer) need to agree on is to test the 
$FFD4-$FFD5 latch on a Coco3. Either it works or it doesn't, simple as 
that. Then you can tell the rest of us if this memory mode works on a Coco3.




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