[Coco] DriveWire issues with Coco 1 F/285 Board

[Gene Heskett]

On Tuesday 02 July 2013 14:47:50 Luis Antoniosi (CoCoDemus) did opine:

> but which one is pin-compatible ?
> 
There was a link posted to a site that had some of the newer, better 
versions listed, all of which will be drop ins.

This one I think:

<http://www.petervis.com/Education/741_Pin_Compatible_Equivalent_Op_Amps/741_Pin_Compatible_Equivalent_Op_Amps.html>

I'd prefer the LM35# family, a lot faster.

> On Tue, Jul 2, 2013 at 2:31 PM, Gene Heskett <gheskett at wdtv.com> wrote:
> > On Tuesday 02 July 2013 14:27:12 Luis Antoniosi (CoCoDemus) did opine:
> > > unfortunately the 741C is one of the few soldered IC's in my board
> > > :(
> > 
> > Its not worth salvaging Luis, nip it off at the chip body and then you
> > can unsolder it one pin at a time.  And put the next one in a gold
> > flashed socket.
> > 
> > > On Mon, Jul 1, 2013 at 7:43 AM, Torsten Dittel <OS-9 at trs-80.cc> 
wrote:
> > > > Gene Heskett <gheskett at ...> writes:
> > > > > The 741C is a very slow op-amp, incapable of doing more than a
> > > > > low amplitude, slew rate limited triangular wave at 31.25
> > > > > kikobaud.  Its full gain bandwidth is only 10Hz!
> > > > 
> > > > ...just enough for the max. 9.6 kBaud (POKE 150,1) the CoCo was
> > > > designed for... ;-)
> > 
> > Not really.  If you ever saw it on a scope, you would cringe in horror
> > that it even worked.
> > 
> > > > > Even if you have to re-arrenge the basing,
> > > > > one of the op-amps in the LM35X family would be many many times
> > > > > more capable a device.  The LM358, in an 8 pin minidip,
> > > > > actually contains 2 fully compensated devices with .1 megacycle
> > > > > plus abilities at greatly reduced power consumption.
> > > > 
> > > > I would have to open this particular CoCo to figure out which
> > > > replacement IC made it in, but it was pin-compatible (and didn't
> > > > require further HW- changes), I guess one of these proposals here:
> > > > 
> > > > 
> > > > http://www.petervis.com/Education/741_Pin_Compatible_Equivalent_Op
> > > > _Amp s/741_ Pin_Compatible_Equivalent_Op_Amps.html
> > > > 
> > > > Regards,
> > > > Torsten
> > > > 
> > > > 
> > > > 
> > > > --
> > > > Coco mailing list
> > > > Coco at maltedmedia.com
> > > > http://five.pairlist.net/mailman/listinfo/coco
> > 
> > Cheers, Gene
> > --
> > 
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > 
> > -Ed Howdershelt (Author)
> > My web page: <http://coyoteden.dyndns-free.com:85/gene> is up!
> > My views
> > <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml>
> > Despite all appearances, your boss is a thinking, feeling, human
> > being. A pen in the hand of this president is far more
> > dangerous than 200 million guns in the hands of
> > 
> >          law-abiding citizens.
> > 
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco


Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene> is up!
My views 
<http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml>
Hitchcock's Staple Principle:
	The stapler runs out of staples only while you are trying to
	staple something.
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
         law-abiding citizens.