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.