[Coco] DriveWire

[Boisy Pitre]

On Mar 6, 2009, at 3:15 PM, Robert Gault wrote:


> Boisy,

>

> I've a question regards the new DriveWire ROM. I've been able to  

> boot with it installed in both MESS and VCC as it is easy to replace  

> the ROM images. I do have an EPROM programmer but thought I would  

> first try the following with a real 6309 Coco3.

>

> The original RGBDOS could be offset loaded into RAM (say $3000) and  

> then moved into the correct location with a short ml program. RGBDOS  

> booted and could be used as a test case this way before burning a ROM.

> I tried that with the new drivewire ROM and it won't work, the Coco3  

> crashes. Here is the ml code that moves the ROM. Any reason why this  

> shouldn't work?

>

> org $7000

> start orcc #$50

> ldx #$3000    where the ROM was offset loaded

> ldy #$c000

> a@ ldd ,x++

> std ,y++

> cmpx #$e000

> blo a@

> jmp $c002

> end start

>

> And yes, I did add the header and footer to turn the ROM into a  

> LOADM binary.


Robert,

Just to be clear: you're wrapping a LOADM header and footer around the  
image and place it on a disk, doing a LOADM (it now resides at $3000),  
LOADM your patch code, then EXEC &H7000.

Seems to me you would be writing right over the existing Disk BASIC  
(or RGBDOS) ROM at $C000, and that could certainly cause a crash??


>

> --

> Coco mailing list

> Coco at maltedmedia.com

> http://five.pairlist.net/mailman/listinfo/coco