Colin MK I


Technical Specifications
The table below shows the specifications of Colin MKI, representing the state of play for most of his life.

Processor Z80A - 4Mhz
Memory 64kB Static RAM
Firmware BOS V2.3 - (2k EPROM)*
Operating system CP/M 2.2
Video display Memory mapped colour Teletext display
- 40 chars x 24 lines
- UHF output (PAL), Composite video & TTL RGB & Sync
Keyboard 7 Bit parallel ASCII
- Carter Professional Model 756
Floppy Disk storage Dual 8" Floppy drives. SSSD
- 77 track (Shugart 801)
Single 5¼" Floppy drive. DSDD
- 40 track (Micro Peripherals)
Printer output RS232 & 20mA interfaces
Serial interfaces Dual channel RS232 ports with full handshaking
Audio interfaces Dual sound processors - (AY-3-8910)
Speech synthesis processor - (SPO256-AL2)

* Original firmware
In the early stages of Colin MK I, the original firmware as supplied with the keyboard interface was called 'CSYS/80'. According to the Custom 80 manual, it should be pronounced 'sea-siss'.

It consisted of two parts; CSYS/80, which was the operating system for the computer that provided all the basic input / output functions taking up 1.5k of the EPROM, and INSECT, which was a debug / execution program that lived in the remining 0.5k. As supplied, my original firmware was serial number 1303. (CSYS/80 V1.05. INSECT V0.09)

Firmware updates
Once I got into improving and extending the basic system as described in earlier pages, I modified the firmware and renamed it BOS. (Basic Operating System).

It is the updated BOS version of the firmware that became the starting point for the HBOS firmware which I created for Colin MK II.