[Coco] CoCo3FPGA new 640x450 256-color graphic mode

[Barry Nelson]

 So what is needed to get the SD slot working in Extended BASIC? I have heard that it is working in OS-9/NitrOS9, so I am guessing that all that is probably needed is an updated Extended Disk Basic ROM? Maybe a modified HDBDOS that has the read write routines replaced to point to the SD card? How does the OS-9 support work? Does it read/write directly to the card or to a FAT file on the card? Also I wonder how hard it would be to bring all the signals for the CoCo I/O bus out to external pins so a real disk controller or a CoCoSDC could be used?