Tim's own version of the Catweasel/Compaticard/whatever

It will require no modification at all to handle those formats. It samples the data at a harmonic of the data rate and writes it back at a harmonic suitable for adjustment for write precompensation. Dealing with the different modulations, as you've named, is a software post-processing task. Likewise, if a little extra effort is put into the design, it can record, quantitatively the location of the index/sector pulses in order to enable reading and writing of hard-sectored diskettes. There are too many mechanical variations to allow simple timing of the theoretical locations of these events. The notion of reprogramming the thing is perhaps a pregnant one, but I have reservations about the suitability of this particular device, for want of pins. A single or pair of 256Kx4 DRAMs might be manageable, but SRAMS would require 30 connections and the EPP/SPP interface would require 13. Then there are a few connections to the drive cable required. As you can see, we're past being out of pins already. A 68-pin device would be more likely to work. Perhaps a video DRAM would work with fewer connections. Dick ----- Original Message ----- From: Eric J. Korpela <korpela(a)ellie.ssl.berkeley.edu> To: <classiccmp(a)classiccmp.org> Sent: Wednesday, July 05, 2000 11:50 AM Subject: Re: Tim's own version of the Catweasel/Compaticard/whatever circuit multiple you