Tristan Mumford schrieb:
What it can't seem to do is read and write. The basic question I want to ask is whether the apple2 has an active high or low for read and write pulses.
The Ehring FDC-4 controller uses two monoflops (1k-1nF) to generate Shugart WD and WG from Apple WData and WReq. I can send you a schematic of the card when interested.
I'm hoping I can get this issue sorted, because it's nearly done! I hope I can get it working right, because I actually decided to use a calculator to figure out final storage capacity *Gasp!*. A 2HD disk should hold 640kb. In it's current form a normal 2HD disk appears as one big single-sided 160 track disk.
As long as you use the Wozmachine as a modulator, 35 data tracks hold 140kB. It does not matter if you connect a 5,25", 3,5", 3" or 8" drive. To use the HD capacity, you would need twice the data rate from the controller. Commercial systems used a regular MFM controller like the WD2979 or �PD765 for these formats. Such a controller chip would allow CP/M and PC MSDOS compatibility.
Patrick