I need to capture the disk format for a number of old DEC MFM disk drive controllers for the microVAX. There are different controllers and their documentation, while very thorough on the software side (system software, not controller firmware), has never included vital details such as the gap sizes and CRC polynomials. Consequently, I have to sample and record the format of each "official" DEC drives in combination with each controller on each of a number of microVAX computers and record it for analysis.

This means I have to capture the data 8x oversampled and record it in RAM, track by track, and send it to a PC, where I can compare it with known format features.

I only have to build one of these tools, and only have to use it once for each catalogued HDD used incombination with each microVAX controller. I then run the formatter and hope like hell that a really fast PC can keep up. USB is too irregular and unpredictable for such applications, so I have to attempt to do this using EPP on a system that has a parallel port. USB might work if I build a deep enough (2GB) FIFO, but why would I want to do that? If Windows didn't take the occasional 2-minute break, it wouldn't be so critical. USB drivers for unique DOS-based hardware would be too much pain.

Fortunately, I have some existing boards that have the necessary features so I can reasonably attempt that.

RE