Advanced Comprehensive Operating System

Advanced Comprehensive Operating System (ACOS) is a family of <a href="/facts/Mainframe_computer/nrBR6rWa">mainframe computer</a> <a href="/facts/Operating_system/8XTuvMh2">operating systems</a> developed by <a href="/facts/NEC/YnlUsMBA">NEC</a> for the Japanese market. It consists of three systems, based on the <a href="/facts/General_Comprehensive_Operating_System/rmboutPB">General Comprehensive Operating System</a> family developed by <a href="/facts/General_Electric/bBm5CzVY">General Electric</a>, <a href="/facts/Honeywell/qjkujlwJ">Honeywell</a>, and <a href="/facts/Groupe_Bull/tlbdToLt">Bull</a>. Two of these systems, ACOS-2 (based on GCOS 4) and ACOS-4 (based on GCOS 7) are still sold, although only ACOS-4 is under active development. ACOS-6 (based on GCOS 8) is an obsolete high-end mainframe platform, which ceased active development in the early 2000s.
The first two models in NEC's <a href="/facts/NEC_SX/fkSpxKPk">SX series of supercomputers</a>, the SX-1 and the SX-2 (released in 1985), ran an operating system derived from ACOS-4, which was variously called either SX-OS or SXCP (SX System Control Program). However, subsequent SX supercomputers, starting with the SX-3 (released in 1990), instead ran a derivative of Unix.
In late September 2012, NEC announced a return from <a href="/facts/IA-64/m6egpGno">IA-64</a> to the previous NOAH line of proprietary mainframe processors for ACOS-4, now produced in a quad-core variant on 40 nm, called NOAH-6.
ACOS-2 runs on <a href="/facts/Intel/SMF0gJJX">Intel</a> <a href="/facts/Xeon/j1M8Hp6D">Xeon</a> servers.
In June 2022, i-PX AKATSUKI server equipped with NEC's original processor (NOAH-7) was released.

Advanced Comprehensive Operating System open-in-new

Advanced Comprehensive Operating System