ImageDisk update

On 8 Apr 2007 at 16:24, Jules Richardson wrote: There is definitely a register-level description and source code for the MK3 out there that shows how to get the PCI resource values from the BIOS. There's also a bunch of source code for the MK I. Myself, I use my own code to drive the cards; I've never needed code The interface to the card is brutally simple--unless the MK4 has added some additional stuff. You step the drive by setting the direction and pulsing the step line. None of this fancy stuff where the CW actually remembers the current cylinder number. About the only thing the CW will do for you is wait and collect data when the the index pulse goes active--and then will stop when the index pulse goes active again. There's a 128K SRAM that holds the data until you're ready to read it back via programmed I/O. The index feature may not be of particular value for some diskettes-- I've got some formats here that don't use the index for anything-- they just start formatting wherever the disk happens to be in its rotation. Generally, I'll collect data under DOS real mode (although Win 9x works okay) and then digest it with a 32-bit program. The data from the catweasel is basically a series of counts between pulses. It's a bit difficult looking at a data stream from the CW and figuring out what you're looking at. I've got a little Windows utility that takes any track and plots the data on a time axis, changing from 1 to 0 with every pulse. The graphical representation really helps to figure things out, particularly when dealing with someone's idea of GCR. Cheers, Chuck