During ZoomFloppy development, Nate Lawson tested and found that the 1571 drive, with it’s faster clock speed and hardware shift register data transfer support, could potentially support serial data nibbling. Current nibbling options require a cumbersome and difficult-to-install parallel cable. As attention was placed elsewhere, the idea was shelved pending initial implementation code.
A while back, Arnd Menge submitted a patch to enable serial nibbling using the ZoomFloppy hardware and the 1571 SRQ line. Continued testing and refinement of the patch goes well. Thanks go out to Arnd for the patch and bug fixes, and to Nate Lawson for debugging this new functionality. Currently, only reads are supported, but write support will be added once the basic concept and initial implementation is proven.
When complete and added to the base firmware and OpenCBM libraries and tools, C128DCR 1571CR owners, who previously were unable to utilize their drive for data nibbling (lack of parallel port option) can utilize this solution to quickly read data from the 1571 drive unit.
We’ll continue to monitor the progress of this new feature. Though the solution is close at hand, software support for this new feature might take longer.