Dave <[email protected]> noted: <...> <quote> That is correct, the assembler that comes with MVS 3.8 is the IBM Assembler XF, and this assembler was also supplied VM and DOS. This is a complete re-write of the Assembler F which came with MVT. There is also Assembler "G" which consists of modifications to Assembler F. I am not sure when Assembler H appeared but thats the pre-cursor to the modern HLASM. </quote>
Assembler H appeared internally around 1970-71; as IBM was moving toward doing development with the predecessors of PL/X management tried to kill it, but it was so popular with IBM's field staff (they could do a SYSGEN in an afternoon rather than a weekend) that it was eventually made into a program product (the first, I believe). Assembler G came from the University of Waterloo, and Assembler XF was developed at the IBM lab in Lidingo, Sweden. <quote> wasn't HLASM originally Assembler H with the SLAC modification... </quote> HLASM adopted many of the SLAC mods (with enhancements, of course!) and added a vast number of additional new features. John Ehrman
