EPROM copier/programmer advice please

[et...@whidbey.com]

I have several EPROMs from the 1980s that I would like to copy so that
I will have backups. I see all sorts of readers/programmers online and
on eBay but I don't know what to avoid or buy. I have EPROMs that I
can practice with. They are good as far as I know but the info in them
is for a different machine. So I was thinking I could copy one, then
program a new one with the copied data, and then compare the two to
make sure all the data was copied correctly. I am assuming that the
software I use to copy and write will also have the ability to compare
the two devices. I may be wrong. In about a month the machine I am
most worried about will be free for long enough for me to do the
copying process. I do know how to handle the boards properly to avoid
static and other damage and I do have a nice tool made for removing
and inserting the devices. Any advice or suggestions?
Thanks,
Eric

[John Robertson]

Hi Eric,

It all depends on the chip. For example - 2716s - most Eprom programmers
can still read those, however if you have 2532s that is harder to find a
reader for. 2732s, 2764s, and later almost any inexpensive device (Wilem
for example) will read those.

If you have 2708s then you will have to buy a legacy Eprom programmer to
read those unless you are adept at making interface modules - you have
to provide +12 and -5 for 2708s. Earlier still devices, and PROMs again
need more specialized reader/programmers.

Most of the 70s games are archived and not too hard to find via MAME.
Which games are you trying to back up?

Or you can talk to someone like my shop where we can read and program
devices right back to 1702As so we could read your chips and give you a
copy of the archive. Not free I'm afraid! Cost depends on the device read.

John :-#)#

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[Dimitrij Klingbeil]

As John said already, the most important part is the device support.
Manufacturers of various EPROM programmers will typically publish long
lists of devices that their programmer is designed to support. First
make sure that the devices (EPROMs) you need to read are supported by
the programmer you intend to buy. Often commonly available "popular"
devices were made by multiple manufacturers and were known by various
similar names, so when looking up device types in a list, it may make
sense to look up the other known compatible type names too. However
beware that there are some devices by certain manufacturers that are
known to be "quirky" and that some theoretically "compatible" devices
need not always be fully compatible. In the most cases a "compatible"
device will at least be compatible enough to read identically, but when
it comes to programming them, beware - there be dragons in the details.

As for any particular programmer, I can't really recommend much due to
the lack of experience. I've used a MiniPro TL866A in the recent past
and found it to be built and working reasonably well. However, I only
had recently made serial EEPROMs and Flash-PROMs to program, nothing
from before the 2000s, let alone 1980s, so no experience with them.
Anyway, here is the device support list of the MiniPro TL866A:

http://www.autoelectric.cn/minipro/MiniProSupportList.txt

Note that some of these devices are micro controllers (AVR, PIC) with
serial interfaces, for these the TL866A (but not the similar TL866CS)
has an in-circuit serial programming interface available via a second
port. Apart for it (the ICSP) these 2 programmers operate identically.

Dimitrij

[mike]

Rule number one...if it ain't broke, don't fix it.
Yeah, right...

It's critically dependent on the EXACT devices you're trying
to program.

If you can read the prom, you can save the data without burning
a new one.

But, it's always good to fully test the process so you will know
it works when you need it.

A prom that verifies in the programmer may not work in the target system
at speed.

Compaq made a laptop in the 90's that had a flash bios.
It would randomly quit booting. If you read the eprom slowly
in the programmer and reprogrammed the same eprom with the same
data you'd just read from it it would work again...until the next time
it broke.
Using a new eprom didn't help. They had left the program enable line
floating when not in use and it would slowly degrade the bits.
The lesson here is that a prom that verifies in the programmer does
not guarantee a working system.

I'm a big fan of rule number one.

[et...@whidbey.com]

On Thu, 30 Nov 2017 11:56:10 -0800, John Robertson <sp...@flippers.com>
wrote:

The machine in question is a CNC lathe with a Fanuc control. Neither
Fanuc or Miyano, the lathe manufacturer, have any more EPROMs.
Eric

[et...@whidbey.com]

The problem is that if it does break it will be hard to find
replacements. I wanna be pro-active and have spares.
Eric

[John Robertson]

So, what are the part numbers of the EPROMs? Chances are it is fairly
modern, and indeed you want to archive those!

I'd archive them for you if you want to make me a small injection mold
or two (ducking).

[John Robertson]

Charge retention was estimated to be over 50 years back in the early 80s
(see link article), but you are well over halfway through that period
and it certainly is a good idea to archive them!

http://ieeexplore.ieee.org/iel6/8298/25930/01156517.pdf

[et...@whidbey.com]

On Thu, 30 Nov 2017 15:12:01 -0800, John Robertson <sp...@flippers.com>

Greetings John,
I'll get part numbers tomorrow and post them. All the EPROMs in my
Fanuc controls are, I think, the same part.
After I read the EPROMs I would also like to look at what is
written in them. In particular some of them have ladders. I spoke with
Miyano, who wrote the ladders for the lathe, and they don't have any
records of what was written. But I'm not sure if I am going to need
special software to make sense of what was written.
I want to do this because the Miyano lathe didn't come with a rapid
override switch or a spindle override switch. Or even a spindle stop
switch that works when the lathe is running a program. These features
are all options for the control and the machine tool maker decides
which ones to use.
The machine moves very fast in rapid, has a 15 hp spindle, and
crashes are nerve wracking. This machine is the only CNC machine I
have seen that does not have a rapid override. Setups with a new
program always make me nervous.

Thanks,
Eric

[John Robertson]

So, the EPROMs hold lookup tables, that are like the old automated looms
shown a long time ago on the Connections (BBC) series?

https://www.youtube.com/watch?v=itd-4lMoXgI

Some of the EPROMs will be operating code, others may be your ladders.
Would need to know the CPU these run under - probably 8-bit like 6502 or
Z80 if early 80s.

Sounds a bit fun.

A couple of fellows I knew back in the 80s and 90s had some rather large
CNC lathes, and mill machines that ran on paper tape. I tried to help
them keep them running but in the end I just didn't know enough (and
this was prior to 1995 - the internet could have saved them) to keep
them going and they shut the shop down as they could not afford newer
equipment. Always felt sad about that. However Honeywell offered zero
support (other than schematics) and they could not find anyone else
remotely interested in trying to help. Nice guys too.

Things were different pre-1995!

John :-#(#

[mike]

On 11/30/2017 3:10 PM, et...@whidbey.com wrote:

>> I'm a big fan of rule number one.
> The problem is that if it does break it will be hard to find
> replacements. I wanna be pro-active and have spares.
> Eric
>

I understand the desire.
I can't count the number of times I started with one good gizmo
and one bad gizmo and ended up with two bad gizmos. Was not the
desired result.
Good luck.

[Look165]

Some companies make copies from a samplefor some "cents".


et...@whidbey.com a écrit :

[bitrex]

If all you want to do is read out the contents of a parallel EPROM and
save it an Arduino-type uP should be good enough to do that with a
little circuit design and code - hook cascaded binary counters to the
address lines, hook data lines to the Arduino, step through each address
one by one and log the data to PC over USB/serial connection.

You could then concatenate the data into a .bin file and use a program
like Binwalk to analyze the firmware and find the code and data
sections. A disassembler like Ida could probably then spit out a basic
disassembly with C-like structure if the code is for a processor it
supports.


<https://gbhackers.com/analyzing-embedded-files-and-executable-code-with-frimware-images-binwalk/>

<https://www.hex-rays.com/products/ida/processors.shtml>

[et...@whidbey.com]

I'm sure you could do everything you describe above but in this case I
really need something that is basically plug and play. But thanks
anyway.
Eric

[et...@whidbey.com]

On Fri, 1 Dec 2017 00:33:14 -0800, John Robertson <sp...@flippers.com>

GEEZ! I forgot to post the EPROM part numbers. They are all 2532
devices. Most are made by TI but a couple are Hitachi.
Thanks,
Eric

[Michael A Terrell]

You can find adapters designed for Commodore 64 computers to change
the 2532 wiring to 2732. They can be built with a couple IC sockets and
a couple jumpers.

[John Robertson]

2532s - those I think can be read by some inexpensive programmers,
burning is another case as they are orphans as far as modern programmers
are concerned.

You can read them as a 2732 if you make an adapter socket if your reader
doesn't handle the 2532s. If you have an old 24 pin wire-wrap socket
with long legs that is easy to use to bend the legs around to gain
access to the data.

https://www.aussiearcade.com/showthread.php/8227-2532-Eprom-Adaptor

I have several tools that handle 2532s easily enough. Xeltek, Data I/O,
Andromeda, and a few other programmers lying around the shop. However I
think I am too far away to be useful to you.

[John Robertson]

Let me see, the pins that need to be exchanged are:

2532 - Pin 21 Vpp, 18 is A11
2732 - Pin 21 is A11 and 18 is /E

So, as I recall, you just need lift pin 21 on your read adapter socket,
and tie that to pin 24 (need 5V to read), then lift pin 18 of the read
socket and tie it to pin 21 of the EPROM reader socket.

Clear enough?

John :-#)#

[bitrex]

If you change your mind someone already did the hard work of designing
the hardware and writing the code here:

<http://simonwinder.com/2015/05/how-to-read-old-eproms-with-the-arduino/>

All you'd have to do is buy the parts and about 20 minutes of soldering,
then plug in and execute the code.

[John Robertson]

I suspect he would be nervous about building something like that where
there exists the possibility of destroying an irreplaceable part. At
least a commercial EPROM burner that can read 2532s is very unlikely to
cause issues, a home-made one has that potential for folks that haven't
done it before.

Another possible solution is for the OP to join one of the machinist
forums and see if anyone else has a similar CNC lathe and has already
backed up the EPROMs.