Newsgroups: comp.robotics
Path: brunix!sgiblab!pacbell.com!tandem!NewsWatcher!user
From: Naber_Michael@Tandem.com (Michael H. Naber)
Subject: Re: Miniboard Kits from SDRTFT
Message-ID: <Naber_Michael-130494081531@130.252.154.164>
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References: <steve-110494223450@fuzbat.pgh.pa.us> <1994Apr12.032534.27701@news.media.mit.edu>
Date: Wed, 13 Apr 1994 15:19:55 GMT
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X-Disclaimer: This article is not the opinion of Tandem Computers, Inc.

In article <1994Apr12.032534.27701@news.media.mit.edu>, fredm@media.mit.edu
(Fred G Martin) wrote:

> In article <steve-110494223450@fuzbat.pgh.pa.us> steve@info.pgh.pa.us
> (Stephen D. Cohen) writes: 
> 
> >     One unidentified (and unbeknownst to me) feature of the board was a
> >space for a Dallas Semiconductor DS1233 and a capacitor in place of the IRQ
> >button.  I don't know for sure, but I'm guessing that it is a reset
> >controller to handle the power on and off situations to prevent EEPROM
> >erasure problems.  If this is the case, I think I would have prefered to
> >have the reset parts instead of the IRQ button.  I have plenty of other
> >opportunities to interupt the processor. :-)
> 
> Mark Reeves is distributing the new "Mini Board 2.0 Extended."  From
> the documentation file cher.media.mit.edu:pub/miniboard/docs/mbextend.txt:
> 
>   * if IRQ button is not installed, a Dallas Semiconductor DS1233
>     "econo-reset" chip may be mounted instead.  This chip assures
>     correct power-on reset operation of 6811 for "mission critical"
>     applications.  (Most of the time the 6811 boots properly when
>     power is applied, but the DS1233 may be used to insure that it
>     -always- boots properly.)
> 
> 
> Cheers,
> Fred
> 
> Fred Martin | fredm@media.mit.edu | (617) 253-5108 | 20 Ames St. Rm. E15-320
> Epistemology and Learning Group, MIT Media Lab     | Cambridge, MA 02139 USA

I purchased two of the boards from Mark, and am pleased, too.  I found that
the DS1233 and capacitor could be mounted on the bottom of the board.  Here
is an ASCII art version of what it looks like from the side:

               =========================================  <- board
                    |  |      _____
                    |  |______|___|  <- DS1233
                    |_____o          <- capacitor

The DS1233's flat side fits nicely against the board and I have nestled
the capacitor on top of its leads, being careful to keep the leads of both
short so there is no possibility of shorting the leads.

It is a tricky job os soldering, but it works well for me.

Michael
-- 
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Naber_Michael@Tandem.Com
