In 1972, Signetics' Jack Curtis hired John Kessler of IBM to lead the design of a new single-chip CPU intended to compete with minicomputer systems. Kessler selected the IBM 1130 as the model for the new design. The 1130, … See more

Signetics sold 2650-based microprocessor development boards, first the PC1001 and then its successor, the PC1500 "Adaptable Board Computer", ranging in price from A$165 to A$400. The chip by itself sold for around A$20. Several hardware construction … See more

Although the 2650 is basically an 8-bit microprocessor, 64 opcodes are actually 9-bit, and another 32 opcodes are 11-bit (using bits in the address field). Of the remaining 128 8-bit opcodes, 124 (126 in the 2650B) are implemented, giving a total of 444 (446) … See more

The overall design of the 2650 was based on the IBM 1130. As such, the 2650 has a number of features that were common on 1960s minicomputers, but rarely found on newly designed microprocessors of the 1970s. Among these, for instance, were status bits that were … See more

For a short time starting 1979, Philips sold a modular 2650 computer called the 'IMS' – Industrial Microcomputer System, based on the See more

The 2650 was supplied in a 40 pin plastic or ceramic DIL enclosure. An external single phase clock signal and a single 5V supply were needed.
The 2650 had many … See more

• 2650 original version with 1.25 MHz maximum clock frequency
• 2650A improved version (minor fabrication changes to improve stability) 1.25 MHz maximum clock … See more