On 2019-06-08 5:40 p.m., Chris Elmquist via cctalk wrote:
On Friday (06/07/2019 at 11:01AM -0700), CuriousMarc via cctalk wrote:
I wondered if it's actually a digtal watch chip (2.5V could have been a couple
of mercury cells in series, LED watches were not uncommon back then).
In which case
On Friday (06/07/2019 at 11:01AM -0700), CuriousMarc via cctalk wrote:
> >
> > I wondered if it's actually a digtal watch chip (2.5V could have been a
> > couple
> > of mercury cells in series, LED watches were not uncommon back then).
> >
> > In which case it would not normally have come in a
>
> I wondered if it's actually a digtal watch chip (2.5V could have been a couple
> of mercury cells in series, LED watches were not uncommon back then).
>
> In which case it would not normally have come in a 0.6" wide DIP. Perhaps
> normally it was a bare chip directly mounted on the watch
On Fri, Jun 7, 2019 at 6:50 PM CuriousMarc wrote:
>
> >The clock chip seems to be a normal digital watch/clock chip. The inputs to
> >it are essentially the 'set' buttons, the outputs are the 7 segment lines and
> >digit strobes. But I have not found a data sheet on it anywhere.
> Tony, looks
gmail.com]
Sent: Thursday, June 06, 2019 8:25 PM
To: CuriousMarc; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: HP98035 Real Time clock and AC5954N clock chip
On Thu, Jun 6, 2019 at 8:57 PM CuriousMarc via cctalk
wrote:
>
> All HP fans in general and Tony in particular,
> I h
On Thu, Jun 6, 2019 at 9:57 PM Tony Duell via cctalk
wrote:
> HP were fond of using NiCds as shunt regulators at that time. The did
> it in many of
> their handheld calculators (HP20 series 'Woodstock', HP30 series
> 'Spice', etc). In
> those it wasn't normally a problem (the calculator
On Fri, Jun 7, 2019 at 4:44 AM Curious Marc wrote:
>
> Thanks, I’ll see if I can find replacements. You can easily see how they get
> zapped: they are 2.5V chips, the NiCd battery *is* the voltage regulator.
> Charging circuit is a simple diode connected to 5V via a resistor. Battery
> dies,
Thanks, I’ll see if I can find replacements. You can easily see how they get
zapped: they are 2.5V chips, the NiCd battery *is* the voltage regulator.
Charging circuit is a simple diode connected to 5V via a resistor. Battery
dies, goes high impedance, somebody plugs it in to try it out and
On Thu, Jun 6, 2019 at 8:57 PM CuriousMarc via cctalk
wrote:
>
> All HP fans in general and Tony in particular,
> I have the exact same problem. HP98035 real time clock module
> (http://hpmuseum.net/display_item.php?hw=168), plugged into a HP9825T
> (http://hpmuseum.net/display_item.php?hw=171),
ctalk-boun...@classiccmp.org] On Behalf Of Paul Berger
via cctalk
Sent: Thursday, June 06, 2019 1:28 PM
To: CuriousMarc via cctalk
Subject: Re: HP98035 Real Time clock and AC5954N clock chip
Are you able to set the date and time on your clock? I had disconnected
one end of the diode in the char
Are you able to set the date and time on your clock? I had disconnected
one end of the diode in the charge circuit and powered the clock from a
lithium primary cell. I got all 8s when the battery went dead but when
it was in that state when I tried to set the date and time any commands
after
All HP fans in general and Tony in particular,
I have the exact same problem. HP98035 real time clock module
(http://hpmuseum.net/display_item.php?hw=168), plugged into a HP9825T
(http://hpmuseum.net/display_item.php?hw=171), accepts commands, reads back
all 8's. Battery is new, is charging and at
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