[Coco] FW: MindRoll (32K) ROM?

[Camillus]

Hi, Barry,

I'm following your conversation about dumping a 32k rom. I was just pondering over this and a following scenario came to me. Could it be that the cartridge on boot, copies the whole contents, addressable with A0 to A15 ( 32768 = 32K ) to ram, and then somehow uses SCS to address one more address line A16, then copy again the whole 32k range to ram, before or after the first block of 32k, in a  64k ram space and then jumps into that ram to start the game.

This scenario explains the use of SCS line and it would be possible since the roms are dissabled when SCS is issued anyway( that is if I understand it right .. LOL). 

If the rom in the cartridge is only 32k (16 address lines (A0-A15)) then there would be probably a 16k wide transfer, and then by executing some code from the first block that is all ready in ram, make A15 high to copy the next 16k in ram.

A way to check my theory could valid is to check in the cartridge if the SCS is really connected to the cocobus. Then make a dump from the eprom and disassemble some code in it to find loops that could point to 16k transfers.

Can you tell me what type ROM is in the cartridge?

Could be of course I'm having this completely wrong...LOL

cb

Sent from Mailbird [http://www.getmailbird.com/?utm_source=Mailbird&utm_medium=email&utm_campaign=sent-from-mailbird]
On 11/8/2015 7:18:30 PM, Barry Nelson <barry.nelson at amobiledevice.com> wrote:
I have the original cartridge, cat# 26-3100. If you have any suggestions about how to dump it, I would be happy to stick it it my multi-pak on my CoCo 3 and dump a copy to a floppy disk. It most likely does have some sort of bank switching scheme, so some code would probably be needed to dump a copy out correctly. I believe I have a copy that runs from disk as well, although I forget if it is the CoCo 1/2 version or the CoCo 3 version.

> Chad H chadbh74 at hotmail.com
> Sun Nov 8 20:00:58 EST 2015
>
> This might explain why many of several of my games in .ROM image format were tripping the SCS line on my EEPROM controller. Fortunately, now that the testing and development is out of the way, the controller ignores the SCS unless needed for .BIN loading.
>
> Perhaps one of the images at
> http://www.colorcomputerarchive.com/coco/Cartridges/ will work still? Thanks for reminding me of that site Robert. For some reason I didn’t have it bookmarked.
>
> - Chad H
> http://sites.google.com/site/cbhlab101/


--
Coco mailing list
Coco at maltedmedia.com
https://pairlist5.pair.net/mailman/listinfo/coco