I've amended CCKDDU64 to cater for 3390's larger than model 27's. It's not pretty, but it seems to do the job.
I've dumped a model-54 that has datasets allocated at cylinders higher than 32760, checked it with cckdcdsk64, attached it to Hercules and all appears good.
I've also dumped a Model-9 with the updated and the previous CCKDDU64. A binary comparison comes up clean, except for cdh_vrm in the ckd device header - the version of CCKDDU64 was updated to 0.3.2.
Where can I place the updated source? Also, would anyone need a load module?
Andrew
