The latest release of this Firmware is detailed in the table below.

Name	Small Computer Monitor
Configuration	S4
Release	2019-06-02
Download	SCM S4 2019-04-30
Device Programming:
Code size	32k bytes
Checksum (MiniPro 6.6)	005C F8DF
Recommended IC	AT27C256R-45PU
Core Components:
Monitor	Version 1.0.0
BIOS	Z180 0.0.2
Included Apps:
– ROM BASIC	Version 4.7b.1
– CP/M loader from CF card	Version 1.0

The firmware is supplied (above) as an Intel HEX format file, which is suitable for use by most PROM programmers. Intel HEX files are a text format, not a binary format. As a result they are larger than the stated code size in the table above.

The Small Computer Monitor’s Components and Apps are described here.

Source code can be found in the Small Computer Workshop download.

Supported Devices

• Z180 CPU (eg. Z8S180xx)
• ACIA #1 at 0x80 (eg. 68B50)
• ACIA #2 at 0x40 (eg. 68B50)
• SIO #1 at 0x80 (eg. Z84C42xx)
• CTC #1 at 0x88 (eg. Z84C30xx)
• Digital I/O at 0x00
• Compact Flash at 0x10 for loading CP/M
• Status LED at 0x00

The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.

If the serial module, or any other module, requires an RC2014 standard 7.3728 Mhz bus clock then the 18.432 MHz oscillator typically used for the Z180 CPU will need to be replaced with a 7.3728 MHz oscillator.

Supported Modules

• Processor and memory:
  • Karl’s Z180 CPU Module (not tested)
  • SC111, Z180 module

• Memory:
  • RC2014, memory module pair:
    • RC2014, 64k RAM module, plus
    • RC2014, pageable ROM module

• Serial port:
  • RC2014, serial module (68B50 ACIA) – retired
  • RC2014, serial module (Z80 SIO)
  • Karl’s #61, serial and storage (ACIA & CF)
  • SC104, serial module (Z80 SIO)
  • SC110, serial and timer module (Z80 SIO & CTC)
  • and others

• Timer:
  • SC102, counter timer module (Z80 CTC)
  • SC110, serial and timer module (Z80 SIO & CTC)

• Baud rate generation:
  • RC2014, dual clock module
  • SC102, counter timer module (Z80 CTC)
  • SC110, serial and timer module (Z80 SIO & CTC)

• CP/M storage:
  • RC2014, compact flash module
  • Karl’s #10, compact flash module
  • Karl’s #61, serial and storage (ACIA & CF)

• Self-test status display:
  • RC2014, digital I/O module

The lack of specific support does not exclude the use of other hardware. It just means the ROM does not do anything specific with it.

Release Notes

The Z180’s internal I/O is set to the range 0xC0 to 0xFF.

Installation – RC2014 ROM and RAM modules

Below are the jumper settings for the RC2014 64k RAM module and the RC2014 pageable ROM modules, when the Small Computer Monitor configuration S4 is programmed into a 27C256 (32k by 8) EPROM.Image