On 9/1/22 19:22, Fred Cisin via cctalk wrote: > But, how about a WD TRACK READ with the index pulse masked?
Well, okay, but I never found that to be very useful, because to achieve correct byte alignment, you need one of the standard address marks to get the data separator working right, which few HS recording schemes employ. That's not to say that it can't be done, but it's a lot of trouble, particularly for MFM encoding. There's also the dodge on PCs of using two drives--one with a standard formatted soft-sector floppy to start a "read track with a very large sector length code" operation and changing the drive select to the second drive while the read's in progress. The "Read Track" feature is useful for recovering data from regular soft-sectored IBM System/3 or 3740-type floppies, however. All in all, a cheap MCU is easier--and cheaper, I think. Consider a little STM32F405 MicroPython board--it runs at 168MHz, timers that can capture pulses at 84 MHz and has about 192KB of fast SRAM inside. Cost is around $11-15 and includes MicroSD and USB interfaces. Similarly, you can get an Option Board working on index-less or hard-sectored floppies by using a cheap MCU to either generate or mask index pulses. You can even use the same MCU to simulate index pulses for equipment requiring hard-sectored floppies. A little 8-pin <$1 MCU is more than adequate for the job. Silicon has gotten so cheap! --Chuck
