As I collected parts for my Interak Computer project, I gained a few Kemitron Computer cards. But what is a Kemitron - could I build one?
Already have an account? Log in.
To make the experience fit your profile, pick a username and tell us what interests you.
It seems the small UK manufacturer Kemitron produced at least three Kemitron models: The 2000 Series, the 3000 Series and the Solo. My cards look to be the correct size for the Solo, but of course I've never seen the other models.
As I find more information, I'll add it into the respective project log.
I know little about this board, although the Interak overview documentation does state that a Tape Interface can be used within an Interak System. Elsewhere, the Interak documentation refers to the board as a "Serial Binary and FM Converter", an indication that it uses frequency modulation to encode/decode a serial stream of binary data.
There is a 1979 Kemitron Electronics booklet “A Guide to SC/MP Programming” that has a description of an assumed earlier but similar TP-A board:
“This board coverts serial binary input data to an audio signal and the converse.” ... “The Kemitron tape board (TP-A) is reasonably sophisticated and uses digital synthesis to produce a near sine-wave output (this is easier to record than a square wave) as well as a majority input gate to reduce the effects of minor tape defects.”
The MZB-3 card is a Z80A CPU card that is well documented, as it is also used within the Interak computer system. The only apparent difference to the Interak card (other than the Kemitron logo) is the Boot ROM contents will likely be different.
In my collection of Kemitron Computer cards I have an OP-3 card. I have not investigated further but a cursory glance would suggest it is an output card with relay control.
In my collection of Kemitron Computer cards I have an SIO4 card. I have not investigated further but a cursory glance would suggest it is a serial I/O card based around the AY-3-1015D UART.
The 1986 PhD Thesis from Loughborough University, that provides the specification for a K3000, also refers to the use of a K2000E.
From the reference, something of the K2000E specification can be inferred:
Processor: Z80 (as Z80 Assembler is used).
RAM: Unknown.
Storage: Unspecified size Floppy Disk Drive.
Interfaces: P.P.I. Interface. Expansion slots for I/O cards. (RTC and 16-channel, 12-bit ADC fitted).
OS: Unknown but CP/M assumed. (MBASIC used).
There is also mention of a Kemitron ADA-5 Card – a bidirectional 12-bit DAC and ADC, which is likely the ADC in use.
I managed to find the specification of a Kemitron K3000E, in a PhD Thesis from Loughborough University, where a K3000 was in use in 1986.
Processor: Z80A, 4MHz.
RAM: 64K RAM.
Storage: Dual 8” DS/DD Floppy Disk Drives.
Interfaces: Expansion slots for I/O cards.
OS: CP/M 2.2.
The Kemitron 3000 series appears to have used the same processor as my Kemitron MZB-3 CPU card, but the form factor is unknown. Dual 8" Drives would require a large(ish) case though.
Some further detail is provided in the September 1979 issue of "Practical Computing" which has an article focussed on Kemitron Electronics. The article describes the Kemitron UBS 3000 as having a modular construction with the option to plug any of a number of cards (Processor, RAM, CPU, etc.) into the system bus. The article also suggests a variety of processors might be available.
This is the only Kemitron model of which I have a picture, and in fact a full advertisement with specification. (Advertisement from "Electronics and Wireless World", April 1985 issue.)
The specification of the Kemitron Solo is:
Processor: Z80A, 4MHz.
RAM: 64K, expandable to 128K.
Storage: Single 300K Floppy Disk Drive, Second Drive optional. Optional RAM Disk.
Interfaces: Dual RS232. Five Expansion slots. RS422 and IEEE interfaces optional. Analogue and Digital I/O cards also available.
OS: CP/M 2.2.
The fact that it had a RAM Disk is unusual, and cutting edge for the time - no doubt driven by its principle use of high-speed laboratory data collection.
It is difficult to say from a picture, but the expansion slots could be for International Sized Cards (4.5" x 8"). This could be the computer I have cards for!
Will
Ted Fried
EtchedPixels
Marek Więcek