ISA Floppy Disk and Serial Controller

This is a place holder page for the ISA Floppy Disk and Serial Controller

Board Assembly

Install the shorter components first this means installing them in the following order

• 24 Mhz Crystal
• Capacitors, resistor arrays
• DIP Sockets
• DIP Switches
• Square sockets
• Floppy connector
• 9 pin serial header

DIP Switch settings

A good starting point is to set the dip switch 2 and 8 ON. This will put Serial port on IRQ 4. and base address 0x3F8 (COM1).

Note: Only one of SW1.1 - SW1.4 should be ON. All switches can be off if software doesn't use interrupt based I/O. Note: One and only one of SW1.5 - SW1.8 switches should be ON.

For the ROM Address you can switch all of SW3 ON except 5 and 8. This will put the floppy controller ROM at address 0xE8000.

Note: If you are using the XT-CF or similar card then the floppy controller needs to be at a lower address.

See the original designer's website for detailed configuration of the DIP switches.

Troubleshooting

The floppy drive works but the C drive is not detected.

This can happen if you have both the XT-IDE and floppy ROM Extensions installed on the same system where the XT-IDE is at a lower address. You will notice that the usual XT-IDE boot screen will not show. In this case make sure the floppy controller address is lower than the XT-IDE.

For example the floppy controller is at 0xCA0000 (higher) and the IDE controller is at 0xC8000(lower) then swap the addresses by adjusting the DIP switches.