Floppy disk controller for Z80/Z180
I have finally finished the design of a floppy disk controller (FDC) board for my generic Z80180 CPU board. It is based on an old Western Digital WD2797A controller chip. The FDC board is connected to the CPU bus with a Euro64 connector. A standard 3.5" 1.44MB PC floppy drive is connected to the FDC board with a 34 pin IDC connector (same as inside a PC). The interface supports standard PC 1.44MB disks with DOS or almost any sector based format.
One disk drive can be controlled by the FDC board. 720KB disks can not be used with the interface and I guess they are obsolete by now. There are jumpers on the FDC board to disable/enable the use of interrupts, DMA and reduced write current for the disk drive.
Click here to view the circuit schematic.
I have assembled and tested one FDC board and I'm currently working on the driver software to support reading/writing/formatting of DOS disks under my OS-X 2.0 RTOS. An assembled FDC board is shown below.
Download pcb.zip which contains the schematic and PCB layout files in Adobe Acrobat (.pdf) format. It also contains PALASM source and JEDEC file for the AMD PALCE16V8Q-15 decoder chip used.
Download driver.zip which contains source code for my driver and filesystem software. The software runs on OS-X 2.0 on my Z180 computer.
View the wd2797.pdf datasheet here.
For more information, questions, feedback etc please contact me at:
francis.gormarker@swipnet.se
Last updated: February 22 2002