In September of 1980, NEC announced a large general-purpose computer system, the ACOS System 1000 (hereafter referred to as the S1000), which was the fastest machine in the world at that time. Compared with the ACOS System 900, which was the previous high-end model in the ACOS Series, the S1000 had 4 to 5 times the processing capacity in environments such as batch processing, online databases and time-sharing systems, and 4 to 20 times the processing capacity in terms of scientific and engineering calculation programs. The arithmetic processing unit employed 128 kilobytes of cache memory, sophisticated pipeline control and an integrated array processor. The system employed a virtual memory system based on segmentation and paging, expanded the maximum segment size to 1 gigabyte, and had 16 gigabytes of virtual memory space per user. A disk cache was provided for improved performance. This made the S1000 the world's fastest computer announced at that time, with a speed of 15MIPS (Million Instructions Per Second) for a single CPU. The S1000 was the first computer supplied on an OEM basis from NEC to Honeywell.
| Model 1 | Model 2 | |
|---|---|---|
| Announcement date | September 1980 | |
| OS | ACOS-6 | |
| Number of arithmetic processing units (EPU) | 1 | 2 |
| Cache memory | 128KB | 256KB |
| Multiprocessor | Max. 2 EPU, | Max. 4 EPU |
| Main memory capacity | Max. 64MB | |
| Number of channels | Max. 68 | |
| EPU element | Bipolar CML | |
| Memory element | 64Kbit DRAM | |
