Most if not all of the people at SHARE that were involved in writing the requirements that resulted in HLASM were users of HASM with the SLAC mods. We tried to pick the most commonly used features for the highest priority requirements and in some cases, we modified the way that we wanted things to work to get around issues that several of us had found with the SLAC mods. And in a few cases, the requirements ended up being rejected by IBM, but most of them were implemented including some that we were not sure could be. In addition, some of our requirements that were initially rejected became part of the HLASM Toolkit like the structured programming MACROs. Thanks John. Lloyd Lloyd Fuller former member of the SHARE Assembler committee
>________________________________ > From: John Ehrman <[email protected]> >To: [email protected] >Sent: Friday, November 22, 2013 3:00 PM >Subject: Re: ASSIST Assembler and HLASM > > >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 > >
