Alt-BEAM Archive
Message #04231
To: "'beam@sgiblab.sgi.com'" beam@sgiblab.sgi.com
From: Wilf Rigter Wilf.Rigter@powertech.bc.ca
Date: Thu, 3 Jun 1999 19:28:41 -0700
Subject: [alt-beam] Re: Transistor MicroCore
in addition the MC14584 is identical to the 74C14 and the CD40106 in terms
of the operating voltage range but all have slightly different trigger
thresholds and hysteresis. So these chips are compatible and interchangeable
but swapping will require "re-tuning".
Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
tel: (604)590-7493
fax: (604)590-3411
> -----Original Message-----
> From: Bruce Robinson [SMTP:Bruce_Robinson@bc.sympatico.ca]
> Sent: Thursday, June 03, 1999 3:36 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: Transistor MicroCore
>
> Tom Edwards wrote:
> >
> > To do the best of my knowledge, he went directly to 74xx14's -- he
> > explicitly mentions "Schmitt inverters" in the patent which was granted
> > in 1994 (five years ago -- ought to have been early enough in the BEAM
> > universe.)
>
> The patent refers to the MC14584 chip, which is a CMOS Hex Schmitt
> Trigger -- main difference from a 74HC14 is it can handle a supply
> voltage from 3 to 18 Vdc (as opposed to the 2 to 6 volts for the
> 74HC14). The MC14584 can also only handle about half the output current
> per device.
>
> I was fooling with Hex inverters (Schmitt & otherwise) 25 years ago, so
> it seems likely that's what Mark Tilden was using too -- smaller chip
> count = easier to assemble = more time to make robots.
>
> Bruce
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