27 Aug
2007
27 Aug
'07
5:41 p.m.
Date: Mon, 27 Aug 2007 14:43:53 -0600> > Glen
Slick wrote:> > If you just need to program 2716's you could pick up a BP
Microsystems> > EP-1 for less than $20 off of eBay.> And what if you don't
use ebay?> Anyhow the point is fix it -- not toss it out.> All I want programed is
28C16's EEPROMS and I can't find a> low cost burner for that around.> IF
COST .LE. $100 THEN CALL SPEND_IT(INCOME)> Ben alias Woodelf>
Hi
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.
Dwight
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28 Aug
28 Aug
3:16 p.m.
On 8/27/07, dwight elvey <dkelvey at hotmail.com> wrote:
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
4:40 p.m.
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). 
4 p.m.
On 28 Aug 2007 at 15:40, dave06a at dunfield.com wrote:
It's not *quite* that simple - for the standard
(slow) algorithm, you
need to hold the data/select for an extended period of time - IIRC
something line 50us. Normal selects won't last long enough, although
one could construct a wait generator that would do it. If you can hang
a socket off parallel I/O ports, you can do it no problem.
That would certainly be my approach if I didn't already own a
programmer. A few latches and other "glue" should do the trick
nicely. The rest is code.
Cheers,
Chuck
6173
days inactive
6174
days old
3 comments
4 participants
participants (4)
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cclist＠sydex.com -
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dkelvey＠hotmail.com -
ethan.dicks＠gmail.com