UPD765B - Single / Double Density Floppy-Disk Controller
The uPD765A/B is an LSI floppy disk controller (FDC) chip which contains the circuitry and control functions for interfacing a processor to 4 floppy disk drives.
It is capableof either IBM 3740singledensity format (FM), or IBM System 34 double density format (MFM) including double-sided recording.
UPD765B Features
* Address mark detection circuitry is internal to the FDC which simplifies the phase-locked loop and read elec- tronics. The track stepping rate, head load time, and head unload time are user-programmable. The uPD765A/uPD765B offers additional features such as multi-track and multi-side read an
