Sinclair Mk14 Replica
Posted by musovern on Feb 7th, 2025 in Sinclair, Single Board Computers, Uncategorized | 0 comments
The MK14 (Microcomputer Kit 14) was a computer kit sold by Science of Cambridge of the United Kingdom, first introduced in 1977 for £39.95. The price was very low for a complete computer system at the time, and Science of Cambridge eventually sold over fifteen thousand kit
The computer is based around National Semiconductor’s SC/MP CPU (INS8060) and shipped with 256 bytes of random-access memory (RAM) and 512 bytes of read-only memory (ROM) as standard. It used an eight or nine red light-emitting diode (LED) seven segment display, there was also optional VDU supporting 32×16 text or 64×64 graphics.[citation needed] Input and output was a 20-key keyboard and reset switch. Cassette-based and PROM storage were optional extras; a sound card was not included but a design for one was provided.
The on-board RAM could be increased in two ways; by the addition of an INS8154N RAM/IO chip providing an additional 128 bytes of RAM along with 16 I/O lines, and also a further 256 bytes by adding two 256 × 4 bit RAM chips giving a maximum of 640 bytes on board. These memory spaces were not contiguous in the memory map. It was possible to connect off-board RAM giving a 2170 bytes total.
The Sinclair MK14 was a minimalist single-board computer with the following key features:
- A National Semiconductor SC/MP (INS8060) microprocessor running at 4.43 MHz.
- 256 bytes of RAM (expandable to 640 bytes).
- 512 bytes of ROM containing the monitor program.
- A 20-key keypad for input.
- A 9-digit 7-segment LED display for output.
- Expansion capabilities for additional memory and peripherals.
These are my Mk14 Replica’s Machines
Mk14 Revision 0
