SuperZapOS/360 executables. The S/360 architecture has an instruction ZAP (Zero and Add Packed) for packed decmial arithmetic, that sets the byte at a given address to a given value. Superzap used this to write data given as a string of hex digits to a given location in an executable file in a matter of seconds. Soon the IBM development labs were releasing all Programming Temporary Fixes (PTFs) to OS/360 in this form. OS/360 included a version called IMASPZAP or AMASPZAP which persisted through MVS, MVS/SP, MVS/XA, OS/390 and probably still remains in z/OS, the distant descendent of OS/360. [Private 2004-02-05 e-mail from Chris Gage, IBM employee and SuperZap user, 1970-].
Last updated: 2007-03-15