Re: IBMi25

On 4/8/2013 11:11 AM, Steve Richter wrote:

I am told that APIs did not start to arrive on the system until the AS400.

My memory is somewhat different. I recall using SPECIAL files on
System/3 and my copy of SC21-7504 verifies this. Reference operation
codes EXIT and RLABL.

Then of course there is SUBR20, used on System/36 (can't swear to
System/34) to read and set the external indicators U1-U8 as well as
SUBR21 used to read and write the LDA when the WORKSTN file is shared
among different jobs. Reference SC09-1818-00.

There were even 3rd party API providers:
http://www.sspi-software.com/rpg_subr.html

EXIT/RLABL were gone on System/38, replaced instead by CALL/PARM. IBM
supplied several callable programs including SUBR23R3 (to retrieve
messages), QCMDEXC (to execute OS commands) and QDCXLATE (to translate
upper/lower case, etc.)

Of course today there are many 3rd party providers of service programs
for the midrange platform.

--buck