Boisy, I just had to rebuild my OS-9 system after a problem with a hard drive. One of many files lost was the source for my current cc3disk so I decided to use rb1773.asm. After several days of struggling without getting the rb1773 code to work, I found a required small change. It may not affect stock SCII units but my altered unit (512 RAM buffer) definitely needs it. I already new that using TFM to transfer to the RAM buffer is problematic at 2Mhz. On my unit, I also can't use a LDD or STD to the RAM buffer on the board at 2Mhz in native mode. I should say that my unit is right on the unstable edge if I used a two byte transfer and it mostly does not work. To accommodate the above, parts of the read/write code need to be changed for SCII units just in case the hardware mod is not the cause of the instability.

NitrOS-9
  - Back-port cc3disk to Level 1 and rename to rb1773
  - Remove CoCo 3 Hi-Res calls from VDGInt and put in separate module
  - Split WindInt into GrfInt/WindInt
  - Back-port cc3io, keydrv, snddrv, joydrv to Level 1??