【NEC】 ACOS System 3800

In July 1990, NEC announced a general-purpose computer, the ACOS System 3800, which was the fastest in the world at the time. Using a single processor, this machine achieved performance about 2.7 times better than the ACOS System 1500 Series by using innovations such as 20,000-gate logic VLSI with a delay time per gate of 70 picoseconds, bipolar RAM with an access time of 1.6 nanoseconds, 1-megabit SRAM, 4-megabit DRAM and other LSI, high-density packging technology for mounting 100 VLSI on a large ceramic substrate of 22.5 centimeters square, and sophisticated bipolar technology incorporating an independently developed branch prediction mechanism and bypass mechanism.

The system achieved superior expandability by realizing a multiprocessor configuration with up to a maximum of 6 processors, and an "expansion data space" specifically for data with a maximum capacity of 128 terabytes.

In order to improve the reliability of multiplex configurations where multiple systems are linked, the system enabled back-up from other multiple systems using the reciproca standby system, and smooth job resumption at high-speed via a job resumption function mediated by the expansion memory unit in case of back-up. In this way, a high-reliability system was achieved.

ACOS System 3800 Specifications
  Model8 Model10 Model20 Model30 Model40 Model50 Model60
Announcement date July 1990
Number of arithmetic processing units 1 1 2 3 4 5 6
Main memory capacity 512MB 512/
Instruction cache 64KB 64KB×2 64KB×3 64KB×4 64KB×5 64KB×6
Operand cache 64KB 64KB×2 64KB×3 64KB×4 64KB×5 64KB×6
Number of channels Max.256 Max.256/ 512 Max.512
Overall data transfer capacity 1GB/s 1/2GB/s 2GB/s
CPU element Bipolar
Memory element 4-Mbit DRAM (EMU)

ACOS System 3800 Specifications
Hardware specifications and functions Number of arithmetic processing units 1〜6
EPU cache size Instructions: 64 KB/EPU
Operands: 64 KB/EPU
Max. main memory capacity 384 MB – 1 GB
Max. number of channels 128 – 512
Total data transfer speed 0.5 – 2 GB/s
Max. extended memory capacity 8GB
Virtual space Basic address space: 2 GB
Data space: 128 TB
Security functions
(program protection)
Independent segmented spaces Memory protection with multiple authority keys
High reliability functions Redundant operation-circuit construction
Processor relief function
→ (auto-continuity function for failed EPUs)
Internal diagnostic processor
System functions Databases Network database: ADBS
Relational database: RIQS II V2
Languages COBOL85
OLTP monitor Large VIS II transaction monitor
Fault tolerance Support for nonstop-system construction (auto-switchover function)
Networks DINA protocol
OSI protocol (FTAM, MHS)
TCP/IP protocol
CASE tools SEA/I software development tools
Operation support functions TOM integrated operation management
FIPS-XE business-process assistance system

ACOS system 3800