Launched in 1976, the Introkit appeared to be very popular. It was the first affordable all-in-one computer everyone could acquire to know a bit about computers.
The basic version was really minimalist: one SC/MP (or "Scamp") microprocessor, one 512-byte ROM containing a monitor program and 256 bytes of RAM for user's programs.
The system was designed to connect to a Teletype - the CPU had serial In and Out pins, but very few hobbyist could afford this massive and expensive equipment. N.S. thus released an optional display kit which was comprised of an add-on card that fitted onto the main board, and a modified calculator for keyboard and display. The machine also needed a dual voltage PSU
Once everything soldered and wire-wrapped, the Introkit was a complete computer and an efficient learning tool. The novice programmer could enter, modify and run programs and thus learn all hardware and software basic concepts of any computing system.
Several of these kits - and other SC/MP machines, were connected to larger computers thanks to the unique and advanced ability of the SC/MP CPU to completely share its system bus with other processors, and thus run smoothly in a multiprocessor environment.
Chris Curry took the Introkit as a starting point to design the MK-14 training board, first Sinclair computer.
Ben Mullett recalls:
I joined NSC Bedford in '77 when the SC/MP was the latest in micros, my first task was to get an Introkit working, with help from Dave Brown. I can still recall some of the Hex opcodes for this machine.... C4 was LDI or 'Load immediate'...
The Introkit was indeed a TTY machine, with a modified NSC calculator case and keys forming the (extra cost) KBDkit and a patched ROM to scan the keys.
The Introkit/KBDkit to MK14 development liaison to Science of Cambridge was Tony Amendt, another National Semiconductor Field Applications Engineer.
He helped me get an MK14 running - allegedly the first kit made - since I was fortunate to be given the task of checking out the kit and instructions. All that was missing were some pullup resistors on the bus. Ran well, but what a weird keyboard! Very Sinclair.....
The SC/MP LCDS was the official development tool - 'Low Cost Development System' and there was a multiprocessing card demo for it that was quite impressive. Might even have that in my attic somewhere!
The multiprocessing architecture reappeared on the Series 32000 (aka NS16000) micros that were used in the Sequent 'Balance' series of Unix machines a decade later.
We need more info about this computer ! If you designed, used, or have more info about this system,
please send us pictures or anything you might find useful.
Special thanks to Jorge Montalvâo Fernandes who donated us this computer !
The SC/MP was the first microprocessor I laid my hands on, sometime around 1976. The National guys were at one of the West Coast Computer Faires in San Francisco, and they were GIVING away the MCU - you then paid a small amount for the eval kit. I turned it into a simple music sequencer, and learned a lot in the process! I''ve always felt that National invented the eval kit culture with this product.
Friday 11th June 2010
Darron Fick (USA)
Hi, I have an old SC/MP (Simple Cost-effective MicroProcessor) National Semiconductor Corp computer that I purchased in 1977. I have all the manuals etc that came with the kit. As you know it interfaced to a ASR33 Teletypewriter. I''ve just got it out from under the house where it had been for many years. I even have a copy of my 1st program that I did it was a random morse code practice progran that I wrote to fit in the 256 bytes of RAM.
Sunday 7th September 2008
Just received a "Telekit" - made by National Semiconductor, datecode 7618. This is pretty much the same electronics, but built into one of their larger pocket calculator cases (looks like the Mathematician PR 4640 with different key mappings). It has an external cable probably to attach it to a tty terminal.