Newsgroups: comp.robotics
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From: sasrer@unx.sas.com (Rodney Radford)
Subject: Re: PICs
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Message-ID: <sasrer.726901461@cinnamon>
Date: Wed, 13 Jan 1993 05:04:21 GMT
References: <C0rHqz.2Jq@iat.holonet.net>
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bsmall@iat.holonet.net (Brad Smallridge) writes:

>PIC UPDATE 

>First of all, we can forget about the Motorola 68L705. I
>was told that after the current supply of parts is depleted, 
>the 68L705 will no longer be available.  On the other hand, 
>Microchip is strengthening its PIC line

Motorla is dropping several members of the 68705 family, but from what I
remember of the last list, there were still over 20 variations of this part
still in full production (in fact the latest member, the 68705K1 was just
announced last summer).

Yes, the Microchip PIC parts are nice, but they require that you put out
money to buy a programmer from Microchip (or Parallax has one too) for about
$200, or use one of the $1K+ universal programmers. Both are kind of expensive
for the typical electronics experimenter. However, if you are REAL NICE to
Microchip, and get the RIGHT FE on the phone, they MAY give you a copy of
the programming specs - with that it is possible to easily build a IBM/PC
controllable programmer for under $20 (for the 16c5x series).

I understand that the 16c71 programs via a serial interface, and that the
programming specs are in the normal data sheets. If so, great - but I haven't
seen the specs to verify this.

On the other hand, many of the Motorola 68705 family are self programming,
where they just copy their internal EPROM image from another EPROM. So you
just program the master EPROM in your normal programmer, stick it in a very
simple circuit, and it does the rest (and the circuit schematics are available
from Motorola, along with PC boards). Or if you were lucky enough to buy one
of the 68705K1 evaluation kits last summer it only cost $50 for the programmer,
a SLUSH development system (not quite as 'cool' as an ICE system), assembler,
and one of their parts.

And no, I have no ties to Motorola - I just like their 16705 line. Now if they
would just get their act together and get me some 68705K1s I would be happy as
I have been 'in the queue' since last July!!!!

--
---
Rodney Radford          || Computer Graphics/Imaging
sasrer@unx.sas.com      || SAS Institute, Inc.
(919) 677-8000 x7703    || Cary, NC  27513

