28 Aug
2007
28 Aug
'07
12:28 p.m.
Subject: Re: INS4004D in Pro-Log M900 PROM Programmer
From: "Ethan Dicks" <ethan.dicks at gmail.com>
Date: Tue, 28 Aug 2007 14:16:18 -0500
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
On 8/27/07, dwight elvey <dkelvey at hotmail.com> wrote:
It also requires the "write pulse" to be 50milliseconds long. Write
is accomplished by supplying VPP (12, 21 or 26V version dependent)
then playing the OE/ and CE/ pins.
Allison
From what I've seen in the spec sheets, one
would just use
a slightly modified 2716 socket of any machine. A few lines
of code should be enough. No special voltages, just special
sequences. All easily handled in software.
My recollection is that the 2716 needs something like 21V or 26V on
the programming pin. As for a modified socket, I have an old "Z-80
Starter Kit" SBC that happens to have a built-in EPROM programmer on
one of the three ROM sockets. There's a toggle switch to disconnect
the programming voltage, but once enabled, you simply write to the
address range of that EPROM socket, and after the data are presented
to the ROM, the circuit wiggles the programming pin to write the
EPROM.
It would not be difficult, in principle, to add this feature to, say,
one of the empty ROM sockets on a PET, especially if you had an
external benchtop power supply injecting the programming voltage
(rather than generating it inside the PET housing).
-ethan