SC191 is a modular Z80 computer designed to run the Small Computer Monitor (SCM), BASIC and CP/M.

- SC191 – Assembly guide
- SC191 – Compatibility
- SC191 – Firmware, SCM S2
- SC191 – Parts list
- SC191 – User guide
- Designing your RC2014 compatible
- SC100 series support
Downloads
See individual product pages for downloads, such as kit contents sheets, schematics, PCB design files and PCB Gerber files.
Errata
Nothing known
Suppliers
See individual parts below.
Parts List
SC191 is made up of the following modules:
Recommended accessories:
- SC346 – Serial to USB C adapter
- SC139 – Serial ACIA module
- SC142 – Power supply module
- SC134 – LED output module
A Compact Flash card is also required for file storage. It is not necessary for basic operation.
The serial module provides higher speed and more reliable communications than the simple serial port built into SC114.
The power supply module provides a reliable reset and a means of powering the system from a separate power source rather than the serial port.
The LED output module is recommended as it provides LEDs that display diagnostic information at startup. It is also useful for general I/O and and an easy way to add debug status during software development.
Compatibility
This system conforms to the RCBus specification v1.0 for RCBus-2014, 40-pin.
User Guide
SC114 includes the CPU, 128k RAM, 32k ROM, a simple 9600 baud serial port, and RCBus 40-pin expansion sockets. See SC114 product pages for more details. The ROM includes the Small Computer Monitor (SCM), BASIC and a CP/M loader. SCM is a capable machine code monitor.
To run CP/M, the Compact Flash interface module (SC145) needs to be added. A Compact Flash card is also required. The CF card must be prepared by formatting and installing CP/M. Install CPM-A if using the simple 9600 baud serial port, or CP/M-C if using the serial ACIA module.
See individual product pages for more detailed information.
Assembly Guide
Build the modules as described on each product page.
See SCM_Apps for some useful test programs.
Recommended assembly and test steps:
- Build and test SC114 (as described on SC114 pages)
- Build and add SC145 (but do not insert the CF card)
- Test again
- With power off, insert CF card
- Check the card with SCM App CF Information
- If the card has not already been prepared:
- Format with SCM App CF Format
- Install the required CP/M version
Notes
- This product is designed for hobby use and is not suitable for industrial, commercial, or safety-critical applications.
- The product contains small parts and is not suitable for young children.