basic computing

Novus 4510 Mathematician

A friend gave me this National Semiconductor Novus 4510 Mathematician scientific calculator made in 1976, and I couldn’t resist taking it apart.

It is an interesting calculator, simply by being a Reverse Polish notation (RPN) machine.

On the inside, the hardware it’s pretty simple, with only two IC’s and a 9-digit 7-segment bubble LED display, mounted on a single side fiber glass PCB. The keyboard seems pretty robust and it’s fixed to the front part of the case, while the PCB it’s mounted on the back part of the case, connected through a flat flex cable.

IC1: MM5760N – 24 pin DIP, Slide Rule Processor
IC2: DS8864N – 22 pin DIP, Segment-Digit Parallel-Input Display Driver




4 bit relay computer

This is my first 4 bit adder built with nothing more than relays.



The forest of wires on the right are used to set the input values (in the picture Input1 = 0100 (4 in base 10) and Input2 = 0101 (5 in base 10)), and the LEDs on the left are used as output indicators for the SUM (in this picture 1001 (9 in base 10)).

1bit half adder with one relay

With just one double relay, you can make an adder capable of performing 1bit additions:

0 + 0 = 0
0 + 1 = 1
1 + 0 = 1
1 + 1 = 0 ( with Carry = 1 )


The circuit design isn’t mine, I found it with a quick google search.



This is the complete schematic of the above circuit.