I remember well. It was very much about saving storage. Storage was precious. Main memory sizes were measured in kilobytes, not megabytes or gigabytes. There was no virtual storage, so main memory size was very much a limiting factor -- not just to performance, as it is now, but an absolute limit on what program and how many programs one could run at once.
Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of Martin Ward Sent: Tuesday, November 30, 2021 8:52 AM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Base-less macros On 30/11/2021 16:36, Paul Gilmartin wrote: > Didn't IBM do that? Doesn't mean that it was a good idea :-) "The 64-bit IBM zSeries (2001) still supports 24-bit mode, 40-plus years later. Why did 24-bit happen? I’m told that it was all for the sake of one low-cost early model, the 360/30, where 32 bits would have run slower because it had 8-bit data paths. These were last shipped more than 30 years ago. Were they worth the decades of extra headaches?" John R. Mashey, "The Long Road to 64 Bits" ACM Queue, 4, 8, October 2006 https://queue.acm.org/detail.cfm?id=1165766 -- Martin Dr Martin Ward | Email: mar...@gkc.org.uk | http://www.gkc.org.uk G.K.Chesterton site: http://www.gkc.org.uk/gkc | Erdos number: 4
