SC145 is a Compact Flash interface designed for RC2014.

This module provides an 8-bit IDE interface via a 40-pin male header. In theory, you could connect other IDE devices, not just the recommended Compact Flash adapter module (shown above).

As this is a very simple interface, which uses the processor bus directly, without buffering, the IDE interface should not be extended for more than a few inches, and only carefully selected devices should be connected. In general, it is best to only use this interface to connect a Compact Flash card.

It is recommended that this module be placed close to the CPU.

Not all Compact Flash cards are compatible with this simple 8-IDE interface. Older cards tend to be best. Large capacity, more modern cards are designed for very fast operation. This means very sharp edges on signals generated by the Compact Flash card. These edges can cause reliability problems with this simple, bus-based interface.

Address

The module has a fixed address, 0x10 to 0x17 (it occupies 8 I/O addresses).

Power

The device plugged into P2 (20 pin, 8-bit IDE) can be either self-powered or can take power from SC145. The recommended Compact Flash adapter module must be powered from SC145.

As it is very likely the connected device will need to be powered from SC145, JP1 has a track connecting its two pads. Thus the jumper header and jumper shunt are optional. If fitted, the track between the pads of JP1 must be cut. This track is on the solder side of the PCB.

Software

This module is software-compatible with the official RC2014 Compact Flash Module. Thus it can be used with any ‘standard’ RC2014 software, including versions of CP/M.

If the system is running RomWBW (which includes CP/M) the Compact Flash can be initialised for use with the CLRDIR command. CP/M does not need to be installed on the Compact Flash card as RomWBW is a ROM-based operating system that includes CP/M.

If the system is running plain CP/M (not RomWBW) the Compact Flash card needs to be prepared before use. Instructions to install CP/M 2.2 onto a Compact Flash card can be found here.

If you are using the Small Computer Monitor firmware then CP/M can be loaded and started from a suitably prepared Compact Flash card with the command “CPM”.