[Coco] CoCo SDC - using the flash banks

[Darren A]

On Sat, Mar 1, 2014 at 3:47 PM, Shane Broadbent <shanetb at telstra.com> wrote:

>
> Hi Darren, so do you require an actual Program Pak or is there a procedure
> to do this using a .ccc file. I have a bunch of those but cannot think of
> how this would be done. I do not have a Multi-Pak, so just wondering if
> there are other options. Something else I tried was to use your flash
> updater tool, and simply renamed a 16k .ccc file to sdc-dos.101 and then
> ran
> the update...again, no error but it did not work :-)
>


This is an operation that requires a bit of effort. What is needed is to
get the contents of the CCC file into RAM on the CoCo so that it can be
written to the Flash.  The first step is to convert the CCC file to a BIN
file so LOADM can be used to load it. Use a Hex Editor application on your
PC to insert a 5 byte pre-amble at the beginning of the file and a 5 byte
post-amble at the end.


Pre-amble:   00 nnnn 4000


The first byte (00) indicates this is a pre-amble. The next two bytes
(nnnn) specifiy the size of the ROM data (original size of the CCC file).
The last two bytes (4000) are the address in RAM where the data will be
loaded. The pre-amble for an 8K cartridge would be 00 2000 4000.


Post-amble:   FF 0000 B44A


The first byte (FF) indicates this is a post-amble. The next two bytes are
both zero since no more data will be loaded. The last two bytes (B44A) are
an address which will produce an ?FC ERROR if you happen to enter EXEC
after LOADMing the file.


Once you have a BIN equivalent of the CCC file you can use the "wimgtool"
utiltiy from the MESS distribution to insert it into a DSK image. With the
DSK image mounted via SD card or DriveWire you can LOADM the BIN file, but
first you need to reserve the RAM above $4000 to hold the data:


CLEAR 200, &H4000

LOADM "filename


Finally, write the data to the desired Flash bank:

WRITE MEM @bank, &H4000,&HC000,&H3E00



Darren