> On Mar 9, 2023, at 5:00 PM, Steve Lewis via cctalk <cctalk@classiccmp.org>
> wrote:
>
> Actually, to answer my own question: if "main frame" refers to the actual
> framing... well the PDP-1, PDP-10, PDP-10 were minicomputers and still
> required a lot of metal "framing" to set up. So, can't they be considered
> mainframes?
>
> (another notion is that mainframes are "multi-user" -- most early
> microcomputers were not multi-user, as they just barely supported the needs
> of one user; I'm not sure if the very first minicomputers were multi-user?)
I wouldn't think so, but "multi-user" is in part an OS question. Many early
machines were large and expensive enough that they would have been called
mainframes if the term had existed back then, but with small enough memory and
lack of hardware facilities like interrupts that make a multi-user OS
problematic. For that matter, recognizable operating systems didn't appear
right at the start. OS/360 is probably not the oldest software system to
deserve the name "operating system" but clearly many of the early machines,
even large ones, were handled by "bare metal programming".
paul
