First computer with real-time clock?

From: Hans B PUFAL <hansp_at_citem.org>
Date: Thu Jul 29 02:35:22 2004

Andy Holt wrote:

> Depends a bit on what you mean by "real time clock".
> In earlier days the (salesman's) definition would include a line frequency
> interrupt.
>
> Under that definition most, if not all, 3rd-generation mainframes had one as
> standard. For most pre-LSI minicomputers it was likely to be an option
> rather than standard.

It goes further back than that. The 7094 modified for CTSS had a
periodic interrupt.

I assume Sellam means a device which will present the time and possible
date maintained independently of the CPU. There I would agree I we are
into the mini era if not the micro.... There was an add on RTC clock
card for the PDP-11 (but Sellam specified "built-in" ;-) If it does not
have to be built in I suspect you could find some earlier examples. ISTR
hearing somewhere of units which attached to mainframes which would
provide tame and date...

   -- HansP
Received on Thu Jul 29 2004 - 02:35:22 BST