IBM Basic assembly language and successors

Basic Assembly Language (BAL) is the commonly used term for a low-level programming language used on IBM System/360 and successor mainframes. Originally "Basic Assembly Language" applied only to an extremely restricted dialect designed to run under control of IBM Basic Programming Support (BPS/360) on systems with only 8 KB of main memory, and only a card reader, a card punch, and a printer for input/output — thus the word "Basic". However, the full name and the initialism "BAL" almost immediately attached themselves in popular use to all assembly-language dialects on the System/360 and its descendants. BAL for BPS/360 was introduced with the System/360 in 1964.

Assemblers on other System/360 operating systems through System/370, System/390, and System z, as well as the UNIVAC Series 90 mainframes made by Sperry Corporation, and the BS2000 Mainframes currently made by Fujitsu, inherited and extended its syntax. The latest derived language is known as the IBM High-Level Assembler (HLASM). Programmers utilizing this family of assemblers also refer to them as ALC, (for Assembly Language Coding), or simply "assembler".

BAL is also the mnemonic of the "Branch And Link" .

The architecture of IBM mainframes has undergone several extensions over the years, including System/360, System/370, System/370 XA, ESA/370, ESA/390, and z/Architecture. Each of these architectures has retained compatibility with most of the features of its predecessor. BAL uses the native instruction set of these machines. It is thus closer to the hardware than third-generation languages such as COBOL.

...
Wikipedia