23 Nov
2007
23 Nov
'07
9:50 a.m.
A simple reader for 2708's can be made with a 24 pin wirewrap socket
with legs that are at least 1 inch long. Bend out the -5 and +12 legs
and hook them up to small batteries (no real current draw) and then
simply read the device as a 2716 in ANY Eprom burner. Works for me! You
can replace 2708's with 2716s by simply bending (on the 2716) the two
pins that engage the -5 and +12 and jumpering them to pin 12 (ground) -
use the Eprom burner to copy the data from whichever half the data is
found in (most likely 0 - 3FFh)... I recommend that you program the data
in both halfs of the 2716 (0 - 3FFh and 400 - 4FFh) for redundancy.
John :-#)#
M H Stein wrote:
-----------------Original Message:
Date: Thu, 29 Mar 2007 07:48:55 +1000
From: Doug Jackson <doug at stillhq.com>
Subject: Re: 2708 EPROM progreammer - old magazines designs
John S wrote:
I have a programmer designed by Steve Ciarcia from BYTE - It uses an
8051AH-Basic (The 8051 with basic embedded) as the controller - and
still works a treat - to this day. - Standalone board, interface via
serial. It was fun to see peoples faces when you shipped a ^C down the
serial line, and dropped through to a READY prompt.
I can find the doco for yo, but it is a high end solution to a simple
problem.
Alternately, I'm more than happy to read an eprom for you, and email
contents - I'm in Oz though. Perhaps there is somebody in the US who
could do the same.
Doug
-----------------Reply:
I have one of those as well; alas, it does NOT do 2708's.
To the OP:
I can scan the KB article for you, but the 2708 programmer is
intended to work with a Motorola MEK6800-D2, and consists of
nothing more than 3 transistors to switch the 27V (and a couple
of switches and a socket for the EPROM). It's all done in software.
mike
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
www.flippers.com
"Old pinballers never die, they just flip out"
As 2708s
are obsolete few moern programmers support them, apart from a few
that cost many $100s. So I thought why not try and build one? I've found
references to the following classic magazines, and I would be willing to pay
a small fee for photocopies or scans of the articles:
Program your next EROM in BASIC. Schematic for a 2708 erasable read only
memory reader and programmer which uses parallel IO ports to set data and
address. The software to drive the programmer is written in BASIC.
Byte - March 1978 page 84 on (main article)
Byte - April 1978 page 62 (Byte Bugs)