Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!swrinde!mips!news.cs.indiana.edu!ux1.cso.uiuc.edu!kline
From: kline@ux1.cso.uiuc.edu (Charley Kline)
Newsgroups: sci.electronics
Subject: Re: NEEDED: POWER SUPPLY FOR M68HC11EVB
Keywords: power supply
Message-ID: <1991May28.193243.4052@ux1.cso.uiuc.edu>
Date: 28 May 91 19:32:43 GMT
References: <823@mixcom.COM> <1991May27.170425.744@Eyring.COM>
Distribution: usa
Organization: University of Illinois at Urbana
Lines: 33

In article <823@mixcom.COM> jjwwjj@mixcom.COM (Robotic Systems) writes:
>After much praise in several newsgroups, I purchased a M68HC11EVB. Now
>I need a power supply! Any suggestions?
>
>Anyway, I need a power supply: INPUT 115VAC, OUTPUT +5VDC @ 0.5A,
>+12VDC @ 0.1A, and -12VDC @ 0.1A. A PC power supply should work fine.

The only thing the HC11EVB uses +12 and -12 for is the RS232 line drivers
and receivers. These are socketed chips; if you pop them out and replace
them with a MAX232 (or other similar charge-pump-based RS232 driver), you
will not need the higher voltage supplies at all.

The EE department here builds little circuit boards with plugs on the
bottom to plug into the 1488 and 1489 sockets on the EVB and the circuitry
on top to do the RS232 driving stuff. Pretty slick.

The EVB is nice, too; I managed to get the assembler to work on my Mac even
though the documentation says it won't work on a Mac II and won't work on an
HFS file system. I've had a couple of projects cooking for a while that
I abandoned because of complexity; now I can effectively replace large
quantities of circuitry with a box labeled "6811". I'd like to start some
prototyping discussions here, maybe.

While we're on the subject of 6811's, which of the various varieties have
people seen available quantity-one? I'm mostly curious about the '711 EPROM
variants. Looking at Motorola's repertoire of 68HC11 derivatives, I can
imagine the prices for them would vary widely.


________________________________________________________________________
Charley Kline, KB9FFK, PP-ASEL                          c-kline@uiuc.edu
University of Illinois Computing Services            Packet: kb9ffk@w9yh
1304 W. Springfield Ave, Urbana IL  61801                 (217) 333-3339