ECB-controlled programs

A program that uses an entry control block (ECB) for execution is called an ECB-controlled or E-type program. An ECB-controlled program must fit into a 4KB main storage block (unless it is a C language program) and is invoked by an enter, create, or control transfer macro request. It is released by a back or exit macro request. (Control transfer is discussed under z/TPF system control transfer.)

ECB-controlled programs that are used to perform system services are called system ECB-controlled. User installation defined programs are called application ECB-controlled programs.

ECB-controlled programs can be written in high-level assembler, C, or C++ programming language. The program type is identified during the offline load process.