[time-nuts] HP8568B firware eproms anyone ?

[John Miles]

Actually, since each EPROM is now 4x bigger than necessary, couldn't you do
all this with just one chip?  The circuit must be decoding a couple of
high-order address lines to drive the chip-select pins of the other three
EPROMs, so you'd just tie those two address lines to the unused address pins
of your new EPROM.

-- john, KE5FX


> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
> Behalf Of Didier Juges
> Sent: Thursday, October 19, 2006 5:34 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] HP8568B firware eproms anyone ?
>
>
> Many CMOS chips draw higher supply current with floating inputs, as the
> internal buffers may bias themselves in the middle of the range, where
> both transistors are turned on. That may lead to increased temperature
> and failure over time. In many cases, floating inputs will simply toggle
> as a function of whatever signal line is nearby through stray capacitance.
>
> I also support tying them to something...
>
> Didier
>