[Coco] GFL football 2 on Cocoflash

[Barry Nelson]

> On Jan 14, 2018, at 5:12 AM, Barry Nelson <barry.nelson at amobiledevice.com> wrote:
> 
> Update:
> 
> First I saw 448 bytes different between my new dump and the file on the archive named "GFL Championship Football II (1988) (26-3172) (ZCT Systems [!].ccc" and 31733 bytes different between my new dump and the file on the archive named "GFL Championship Football II (1988) (26-3172) (ZCT Systems [b1].ccc”! So based on what I dumped from my cartridge, both are bad! One is close, only 448 bytes different out of 32768, but still different. The differences for the the one with 448 bytes different start at offset 15873 or address $FE01 in the high bank so this could just be bytes that are never accessed in the rom that are hidden under the vector page. I read $FF for these bytes. My method of reading was to read it in the CoCo 3 by mapping the cartridge and reading the rom address.
> 
> Secondly, I did not try either copy from the archive but I now know that mine works as I tried my dump.
> 
> My dump is available right now at: https://drive.google.com/open?id=1DiwRvVeJY5s2il_9hPeSH2hi5iXMeoyO <https://drive.google.com/open?id=1DiwRvVeJY5s2il_9hPeSH2hi5iXMeoyO>
> 
> Program ftball0.bin first, then ftball1.bin, in the menu data statement add an entry to start the bank where ftball1.bin was programmed with a type code of 2. Ftball0 will be mapped in after ftball0 starts. The file prgflash.dsk is a virtual disk file which contains the CoCo Flash utilities, ftball0.bin, ftball1.bin and the program I used to dump the rom which I just slapped together, dumprom.bas. Please forgive the way it displays a “garbage” screen while it is running, but it seems to work. It uses the USR4 routine from prgflash.bin which reads a byte from cartridge rom and returns it to BASIC.



Further update:

I updated the program and got a dump that is more similar to “GFL Championship Football II (1988) (26-3172) (ZCT Systems) [!].ccc”, it is now only 195 bytes different and all those bytes that are different are in the I/O page at $FF00-$FFFF. The change I did to the dumprom.bas program was to change the flags at $FF90 to disable the vector ram at $FE00-$FEFF. My previous program was read the vector ram instead of rom for those 256 bytes. I don’t know any way to avoid reading the I/O page at $FF00-$FFFF though, so those bytes will be wrong, but it shouldn’t matter since the rom has no way of reading them either. The difference between “GFL Championship Football II (1988) (26-3172) (ZCT Systems) [!].ccc” and “GFL Championship Football II (1988) (26-3172) (ZCT Systems) [b1].ccc” is that “GFL Championship Football II (1988) (26-3172) (ZCT Systems) [!].ccc” has the two 16k banks reversed, and “GFL Championship Football II (1988) (26-3172) (ZCT Systems) [b1].ccc” does not, so it looks like those dumps are valid. I also fixed my dumprom.bas so the display is now correct and it has a progress bar you can watch. The updated files are in the link above. If you used my previous GFL Football files in a CoCo Flash, they should work and there is no reason to replace them. The dumprom program should be usable by anyone with a multipak and either a disk controller or DriveWire to dump other roms.