Data I/O Series 22 EPROM Programmer help

From: Ian Primus <>
Date: Sun Oct 19 17:10:35 2003

On Sunday, October 19, 2003, at 04:00 PM, Tony Duell wrote:

>> The more I tinker with this, the more I am suspecting a hardware
>> problem. While trying to revive the power supply, I was measuring
>> voltages that were pretty far off, all of them too low. Now, the power
>> supply seems to have stabilized, and the voltages are consistently
>> close to correct. They are a fuzz low, but it's within the
> Have you checked the supply lines for ripple (using as 'scope)? If not,
> do so -- some regulators get confused if there's significant ripple,
> and
> set the average voltage too low. Of course ripple will cause problems
> for
> the rest of the circuitry too.
>> specifications that the manual gives. (i.e. 15 volts is about 14.8
>> volts, but it's close enough). I measured voltages at the 1488 and
>> 1489
>> chips, and they are just about what the data sheet says is nominal
>> (Nominal is 9V, and -9v, I'm reading about 8.9v and -8.89v). But, from
> The 1488 will work fine at that voltage.
>> the looks of the solder and some residual flux on the top of the
>> board,
>> it almost looks like the 1488 has been replaced before. If this chip
>> is
> Quite possible. Line drivers (and other chips connected to external
> connectors) live a hard life, and are often damaged by misconnections
> to
> said connectors (although the 1488 is generally pretty immune to such
> damage) and voltages induced on cables connected to the connectors.
>> bad, I would assume that it would prevent me from seeing any output,
>> but the input would still work, since the 1489 is obviously
> Yes.
>> functioning. If I feel adventurous later this afternoon, I think I am
>> going to try to desolder the 1488 and replace it with a socket. I know
>> I have another 1488 or two kicking around here, so I'll see if that
>> does any good.
> Trace the data output pin on the RS232 connector back to the 1488. Then
> use a 'scope or logic analyser to see if that section of the 1488 gets
> any input data (the input is at normal TTL levels, BTW). If it does,
> then
> the 1488 is faulty. If not, then you've got a problem further back
> (either the serial chip is defective, or more likely it's not being
> told
> to send anything by the programmer's firmware).
> Have you looked at the handshake lines at the RS232 connector. I would
> start by making sure that all the input handshakes (CTS, DSR, CD on a
> device, for example) are connected to a +ve voltage (if you can find an
> output handshake line that's +ve, use that, otherwise use a 9V battery
> for testing, +ve termianl to the handshake lines, -ve terminal to
> signal
> ground). Some devices won't send anything if one of the handshake lines
> is deasserted.
> -tony

I did manage to get the EPROM programmer working the other day, I
should have posted it... sorry. But, thanks for the help, and I'll keep
this email so I have a starting point if it dies again. I ended up
replacing a limping capacitor in the power supply, as well as the 1488.
Now, I am able to read, write and erase EPROM chips just fine (it has a
built in UV lamp). I do still have a major problem, although it isn't
hardware related. I really need 2732 EPROM chips for making Atari 2600
cartridges. I only have one at the moment. I was successful in making a
2732 EPROM cart, a 2764 EPROM multicart (two games on one cart with a
switch to select them), and a partially working 27256 EPROM cart with
three switches to select the games. But, I really would like to be able
to make permanent, single game carts for homebrew titles (currently,
all I have made are test carts with sockets), and the 2732 EPROM is the
easiest thing to deal with when making carts, since I don't have to cut
part of the board to make it fit. I have a very large pile of 27cx321
chips, made by a company called ICT, but I have been unable to program
them, since my programmer doesn't have the codes for them in the
manual, and they don't work at the normal 2732 setting. I can't find
the pinout or any information on these chips anywhere, so I don't know
what they would be equivilent to. Also, I don't know if there is an
updated chart for the Data I/O Series 22, I have version 05 firmware,
but the chart in the manual only goes up to version 02. Data I/O has no
information on this programmer on their web site, other than a message
saying that they no longer support them. Any ideas?

Also, somewhat EPROM programmer related, does anyone know what type of
PROM chips are used in the IBM System/23 Datamaster? I haven't been
able to identify them, the markings seem to be IBM part numbers,
instead of PROM part numbers. I need to replace a bad chip in my
System/23 (see my other post about the System/23). Also, while I'm at
it, I would like to back up the code in the other PROM chips as well
(or at least the ones that are in sockets), if one chip is suffering
from bit rot already, I am concerned about the others as well. If
anyone else on the list has a working Datamaster with socketed ROM
chips, I would suggest dumping all the ROMs if possible, I know of at
least one other System/23 out there with a bad ROM problem, and there
are likely to be more in the future.

Thanks for your help!

Ian Primus
Received on Sun Oct 19 2003 - 17:10:35 BST

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