[Coco] 32K carts?

[Joe]

That is interesting. I wonder now if all the 32K images floating around the 
net are backward like that.
When I was working on getting these running I jut assumed the images were 
correct and my MMU emulation was off. now I'm not sure. I've got a real 
Rampage! cart. Does anyone know if the chip inside it is pin compatible with 
a 27256. I'll try to pry it out and read it on an external Eprom programmer.


----- Original Message ----- 
From: "Mark McDougall" <msmcdoug at iinet.net.au>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Tuesday, October 23, 2007 5:37 AM
Subject: Re: [Coco] 32K carts?



> Joe wrote:

>

>> When you switch to 32K External it gets wierd.

>> $C001 to Whatever is mapped to the first 16K of the ROM and $8000 to 

>> $C000 maps to the last 16K of the ROM. This makes sense as any code 

>> running from rom say at $C??? would need to turn on 32K External mode, 

>> but when that happens if it was a liner map the code that was executing 

>> would "jump up" 16K.

>

> Thanks Joe - that's done the trick. I had to swap the upper and lower 16KB 

> in Arkanoid and it runs now! Presumably Rampage has the same issue.

>

> I need to order a couple of more passives now to be able to test the flash 

> option and the "Flash2" cart.

>

> For those few interested, I'll do some pricing very soon. I've been 

> ultra-busy the last few weeks and have only been able to devote the odd 

> minute here-or-there to this project...

>

> Regards,

>

> -- 

> |              Mark McDougall                | "Electrical Engineers do it

> |  <http://members.iinet.net.au/~msmcdoug>   |   with less resistance!"

>

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