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.