 | |
| General information | |
|---|---|
| Launched | 1976 |
| Discontinued | 1977 |
| Common manufacturer | |
| Performance | |
| Max. CPU clock rate | 4 MHz |
| Data width | 8 |
| Address width | 12 |
| Architecture and classification | |
| Instruction set | Electronic Arrays 9002 |
| Number of instructions | 55 |
| Physical specifications | |
| Package |
|
The Electronic Arrays 9002, or EA9002, was an 8-bit microprocessor released in 1976. It was designed to be easy to implement in systems with few required support chips. It included 64 bytes of built-in RAM and could be directly connected to TTL devices. It was packaged in a 28-pin DIP which made it less expensive to implement than contemporary designs like the 40-pin MOS 6502 and Zilog Z80. Today it would be known as a microcontroller, although that term did not exist at the time.[a]
The 28-pin design did not have enough pins left over to implement a 16-bit address bus, and instead had 12 address lines which limited main memory to 4,096 bytes. This was not a significant limitation at the time, as memory was still very expensive and the target market could often make do with the internal RAM. There was a single 8-bit accumulator used for arithmetic and eight 8-bit registers it could use for storing temporary values. These were supported by another eight 4-bit registers which acted as the most significant bits of the 8-bit registers, extending them to 12-bits for indexing and similar address manipulation.
Electronic Arrays (EA) had problems with the new depletion-load NMOS logic fabrication line and struggled with deliveries. By 1977, the 6502 and Z80 had taken over much of the market, and in November EA stopped selling the design. The company was sold to NEC the next year.
- ^ Wickes 1976, p. 36.
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