Subject: Re: Dennis Ritchie has died

From: "Barry L. Kline" <blkline at attglobal.net> On 10/20/2011 02:03 PM, vintagecoder at aol.com wrote: My point was the foundations of S/34 and S/36 led to the AS/400. I left out S/38 in error. IBM has usually built upon what goes before and it is rare (although probably not without precedent) for them not to include previous architectual elements and software in the next machine, OS etc. in a series. I believe (but again I am not certain) the AS/400 even offered some level of source compatibility for S/34 or S/36, as it is also unusual for them not to be vitally concerned that stuff that ever worked will always continue to do so. Here's a link to a paper on the development of the AS/400. It may not be authoritative: https://har2009.org/program/attachments/27_har_as4.pdf It says, in part: "Rochester's backup plan was [sic] Siverlake. This project took some stuff AS/400. In many ways the AS/400 was actually just a new implementation of the S/38." It does say it was a new implementation of S/38 as you said. But it also says it took stuff from S/36 as I said, and S/36 in turn grew out of S/34.