CB UNIX

Columbus UNIX, or CB UNIX, is a discontinued variant of the <a href="/facts/UNIX/0pNL2seI">UNIX</a> <a href="/facts/Operating_system/8XTuvMh2">operating system</a> used internally at <a href="/facts/Bell_Labs/fKP5Gk0H">Bell Labs</a> for administrative databases and transaction processing. It was developed at the <a href="/facts/Columbus%2c_Ohio/mREa53Ub">Columbus, Ohio</a> branch, based on <a href="/facts/Version_6_Unix/ev0YCVb4">V6</a>, <a href="/facts/Version_7_Unix/ju5nRs7k">V7</a> and <a href="/facts/PWB%2fUNIX/jXR0LT4j">PWB</a> Unix. It was little-known outside the company.
CB UNIX was developed to address deficiencies inherent in <a href="/facts/Research_Unix/5oWmUdwo">Research Unix</a>, notably the lack of <a href="/facts/Interprocess_communication/cIQYyT6y">interprocess communication</a> (IPC) and <a href="/facts/File_locking/QektVCQs">file locking</a>, considered essential for a <a href="/facts/Database_management_system/VYcpkevb">database management system</a>. Several <a href="/facts/Bell_System/GspEoeEF">Bell System</a> operation support system products were based on CB UNIX such as <a href="/facts/Switching_Control_Center_System/0Cg5fWqE">Switching Control Center System</a>. The primary innovations were power-fail restart, <a href="/facts/Line_discipline/0vqvgF4o">line disciplines</a>, terminal types, and IPC features.

The interprocess communication features developed for CB UNIX were message queues, <a href="/facts/Semaphore_(programming)/BrE1W4Je">semaphores</a> and <a href="/facts/Shared_memory_(interprocess_communication)/zmpH7WuV">shared memory</a> support. These eventually appeared in mainstream Unix systems starting with <a href="/facts/UNIX_System_V/Epm6GEY4">System V</a> in 1983, and are now collectively known as System V IPC.

CB UNIX open-in-new

CB UNIX