Electronic ring counters are the counterpart of mechanical counter wheels. Relays driving the counter wheels are replaced by vacuuum tubes (also named thermionic valves). The concept is developed by Eckert and Mauchly in the ENIAC, the first electronic computer operational in 1945 and completed in 1946. The use of electronic techniques increased operating speed enormously. Like counter wheels, numbers are stored in decimal form. The ring counter contains 10 vacuum tubes, one of which conducts current at any time. Pulses enable the next vacuum tube to become active. In this way the unit counts pulses from 0 to 9, indicating a carry when it switches from 9 to 0. The ENIAC had in total 20 accumulators consisting of 10 such ring counters. The use of termionic tubes as switching elements became common practice in early computers. In 1950 Eckert and Mauchly build the UNIVAC, the first commercial computer in the US. They started their own company, the Eckert-Mauchly Computer Corporation, later on acquired by Remington Rand. The unit shown, holding ten gas-filled 2050 triode tubes, is a decimal ring counter as used in the first Univac computer. It connects to the computer's circuitry by means of 26 silvered conical 'pins'.

Punch cards are selected mechanically by vibrating a card deck while some subset is fixed by needles. Used in libraries in the pre-computer era. Capacity up to 7000 titles.

met P8085A processor 2953D '76

The SDK-85 MCS-85 System Design Kit was a single board microcomputer system kit using the Intel 8085A processor. The kit had to be assembled manually. The prototype area on the PCB provided for additional components and circuitry for experiments.
A preprogrammed ROM of 2 KByte was supplied with a system monitor. The System Development Kit (SDK) single-board computers allowed the engineer or student to enter object code from a keyboard or upload it through a communication port, and then test run the code

met P8085A processor 2953D 1976

Intel 8085 development system. To be used with ISIS-II operating system.

Rev. G serienr. 5093

In large black suitcase. Connects with SCSI-card in dedicated PC (22-04-15-02).

The LSI-11 is introduced in 1975 as first PDP-11 model using large integration. The entire CPU is contained in 4 LSI chips on a dual, quad board. In fact the LSI-11 can be considered as a microprocessor with additional on board functionality, such as micro debugging, I/O support and booting from disk. It uses a simpler variant of the Unibus called QBUS with multiplexed address and data wires.

Single 19-inch rack of the 100-node multiprocessor machine

Patent 3094786

aangeschaft door H. Tattje

Zelfbouwkast met een aantal zelf ontworpen transputerkaarten

The Wang model 500 - developed in 1970 as follow-up of the model 700 - was the first electronic calculator that uses Intel semiconductor memory. The calculator could output results both on a display as on a printer. Several versions of this model have been sold from 1971 up to 1975. It list price at introduction was $2700.