Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!microsoft!gordonl
From: gordonl@microsoft.UUCP (Gordon LETWIN)
Newsgroups: sci.electronics
Subject: Re: EPROM Programmer for the 8751
Summary: programming 8751 chips
Keywords: 8751, EPROM
Message-ID: <60161@microsoft.UUCP>
Date: 31 Dec 90 19:48:36 GMT
References: <1990Dec9.175301.4000@NCoast.ORG> <steveh.661523748@tasman>
Organization: Microsoft Corp., Redmond WA
Lines: 32


Re: programmers for 8751s - there are three routes that you can go here.
You can get a "universal" programmer that programs them directly - JDR
sells one for about $500, I have one and it works.

If you have a regular eprom programmer you can buy a little adaptor, for
about $120, which will allow you to program an 8751/8752 as if it were
a 2732-series eprom.  This adaptor reduces the programming voltage,
provides the crystal signal needed by the 8751, etc.  I have one of these
and it works.  See the ads in the CirCuit Cellar magazine (forget title)
or in the back of "embedded systems" mag.

Finally, Dallas semi makes a 8751 equivalent that has 8 or 32K of battery
backed RAM - good for at least 10 years.  You can dynamically assign the
ram to be either "eprom" or "extended RAM" so that you can have, say, 
16K of code and 16K of extra RAM.  These chips are programmed over the
built in serial port (they have a built in ROM monitor!) - you just give
them the "accept program" command and then feed them Intel format, as I recall.
They range from $80 to $120 in oneies, but they have three big benefits:
	1) you can buy them in onesies directly from Dallas Semi, and
	2) they require no programming support besides a serial port on
		your PC
	3) you can debug your program by writting log info into the extra
		ram and then, after the crash, read that log info back out
		via the built in ROM monitor.  Not nearly as good as an ICE,
		of course, but sometimes a very useful technique.

So if you're using a small # of chips, the dallas route makes sense; their
higher cost eliminates the need for a programmer and may eliminate the
need for an ICE.

	gordon letwin