From: Gary Tait
Subject: Re: What would you want in an EPROM programmer?
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Date: Wed, 25 Sep 2002 11:49:34 -0400
NNTP-Posting-Date: Wed, 25 Sep 2002 11:46:09 EDT
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On 25 Sep 2002 02:23:57 -0700, firstname.lastname@example.org (Al
>I'm in the middle of designing an EPROM programmer. At the moment,
>it's based on a PIC16F877. The only other IC's involved are a few 4040
>counters for addressing and a MAX232. I plan to write some software in
>java to controll the thing. I'll have 32 address lines, and several
>programming methods (I'll mainly use the PRESTO II one). However, I
>have never designed a circuit contai an EPROM - This project is just
>for fun :-)
Why not work on somehow directly addressing the EPROM?
I would find it cumbersome to have to step through many address it get
one. Perhaps use 4015 shift registers like thw willem programmer.
If you are going to use a micro, a terminal interface on it would be
great, just upload that hex file using a terminal program and go.
Perhaps some enterprising programmer could write a GUI for it.
>I have a few questions:
>1. The programming voltage is 13V - is this OK for most modern
>EPROMS's? I could make it varible by the PIC, but I don't know if it's
>worth the effort.
No, answered elsewhere. Maybe a linear voltage adjustment from 0-5 to
12.5, optionallt to 22 V.
>2. In order to allow many devices to be programmed, I was planning on
>having a header, like an 8 bit ISA slot, on the programmer. Different
>daughterbaords for different devices could be placed into this header.
>I was planning on getting the PIC to recogonize which daughterboard
>had been inserted and adjust the programming parameters accordingly.
>Does this sound like a good idea?
Maybe a berg header connector, in addition to a standard JEDEC 32 pin
DIP, but then again you are developing a circuit, an individual
constructor can do what they please..
>3. Since FLASH ROM's are popular nowadays, would it be useful to
>include flash rom support into this thing?
>4. Finally, what LED indicators would be useful? I was thinking power,
>RS-232 comms and Write.
>Thanks for any suggestions...
>Official Sci.Electronics.Design Kook since 25 September, 2002 :-p
Also, if possible, include EEPROM/PIC/AVR programming, and possibly a
mode where, through terminal commands, individual pins could be turned
on and off and read.