First computer with real-time clock?

From: Vintage Computer Festival <>
Date: Sun Aug 1 17:42:41 2004

On Sun, 1 Aug 2004, David V. Corbin wrote:

> I have to disagree with you completely!
> You are NOT being pedantic!
> An RTC is indeed any source of information which can be used to monitor the
> passage if time. It does not need to have any synchronization with "wall
> time" at all.
> The RTC may just provide an periodic norification that a certain amount of
> time has elapsed [16.666mS for a 60Hz LTC] or may have register(s) for
> accumulating a number of these events. If the processor contains built in
> timers that can divide a clock signal, then any of these can be considered
> an RTC.
> Once any type of RTC exists, a computer can be programmed with a value which
> matches the current "wall time" and use the information from the RTC to
> update the wall time.

Right. So what I'm trying to determine now is whether the IBM 650 had an
internal hardware counter facility that could be accessed from within
software to allow for keeping time. And if not, were there any clock
products IBM made that could interface to the 650 to generate the local
time/date upon being polled?

Sellam Ismail                                        Vintage Computer Festival
International Man of Intrigue and Danger      
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Received on Sun Aug 01 2004 - 17:42:41 BST

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