Open Tape Reader design

The SAXO USB/FPGA board arrived yesterday, and the designer didn't bother to bring any of the USB chip's unused I/O out to vias, so the analog board will have to have a PCA9555 16 bit I2C I/O chip on it to control the I2C chip enables on the TZA1000s. The PCA9555 also provides 7 extra low speed I/Os for bit fiddling on the analog board. It occurred to me over the last day or two that it would be simple to also make this a "USB Catweasel", so when I lay out the analog board, I'll put buffering on it for a 50 and 34 pin floppy connector and run them over to some of the unused pins on the FPGA. It might even be possible to take one of the analog inputs and tap onto the preamp output of a floppy and bypass the data separator on the drive, capturing analog flux transitions from the head directly. This may make it possible to recover data from marginal media that can't get through the drive's data separator.