Please need help about 2708 eprom...

[JA]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

 

[RFI-EMI-GUY]

JA wrote:

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

Try googling for 2708's. There is stuff out there, a lot of arcade game
sites talk about reading rom images, maybe someone in that field can
help out. An old type that might work are the Data I/O models.

Also;
The Dataman page says theirs do 2708's. Very pricey. I would research
all models that claim to do 2708's and go to e-bay and pick up a unit.

http://www.dataman.com/eprom-programmer.aspx

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[RFI-EMI-GUY]

JA wrote:

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

Try googling for 2708's. There is stuff out there, a lot of arcade game
sites talk about reading rom images, maybe someone in that field can
help out. An old type that might work are the Data I/O models.

Also;
The Dataman page says theirs do 2708's. Very pricey. I would research
all models that claim to do 2708's and go to e-bay and pick up a unit.

http://www.dataman.com/eprom-programmer.aspx

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"©

"Treason doth never prosper: what's the reason?
For if it prosper, none dare call it treason."

"Follow The Money" ;-P

 

[JA]

Try googling for 2708's.

Yes i'm doing this in the last 2 months!

Also;
The Dataman page says theirs do 2708's. Very pricey. I would research all
models that claim to do 2708's and go to e-bay and pick up a unit.

Exaclty! I'm monitorizing ebay.com ebay.de ebay.fr and ebay.it

But no luck, just modern type eprom , from 2716 and up!

 

[CJT]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

I think Needham's used to make a reasonably priced programmer. You can
probably find one on eBay if you watch for a while.

 

[CJT]

Yes i'm doing this in the last 2 months!




Exaclty! I'm monitorizing ebay.com ebay.de ebay.fr and ebay.it

But no luck, just modern type eprom , from 2716 and up!

The fifth post here may shed some light on why:

http://www.atariage.com/forums/index.php?showtopic=108781

 

[James Sweet]

Yes i'm doing this in the last 2 months!


Exaclty! I'm monitorizing ebay.com ebay.de ebay.fr and ebay.it

But no luck, just modern type eprom , from 2716 and up!

Willem might work if you make up an adapter to supply the -5V and
translate the pins.

You also may be able to adapt a more modern eprom to the task, I've done
this with RAM chips, disconnecting the -5V and adding a jumper to make
newer 4164 RAM chips work in place of the original chips on Williams
game boards. I've adapted Dallas battery backed SRAMs to replace various
obsolete writable memory chips too.

 

[Eeyore]

I think Needham's used to make a reasonably priced programmer. You can
probably find one on eBay if you watch for a while.

I have a Needham's PB-10 here. Not sure if it reads 2708s and the Needham's site
isn't responding. I haven't got the software installed on this PC but I do have it
elsewhere.

Graham

 

[mpm]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

Can't you just cobble up an adapter to treat your 2708 as if it were a
larger memory device.
So what if the high read addresses come us as "00" or "FF" Hex.
Just edit it with a text editor. Or am I missing something here?

-mpm

 

[Arie]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to
make it.
Can someone help me?
And if someone got an old eprom programmer let me know!

1. to get the code from the 2708 send it to someone and get the HEX file
back, you don't need to buy a vintage programmer then.
2. use a 2716 in an adapter socket to replace it, ground the 2716's highest
address pin.

Unless you really want to keep it 'vintage'...

Arie de Muynck

 

[[email protected]]

1. to get the code from the 2708 send it to someone and get the HEX file
back, you don't need to buy a vintage programmer then.
2. use a 2716 in an adapter socket to replace it, ground the 2716's highest
address pin.

Unless you really want to keep it 'vintage'...

Arie de Muynck

Better. Put the data in 2 blocks both 0-1K and 1K to 2K so it doesn't
matter if the MSB is hi or low.

GG

 

[Eeyore]

I have a Needham's PB-10 here. Not sure if it reads 2708s and the Needham's site
isn't responding. I haven't got the software installed on this PC but I do have it
elsewhere.

It only goes as low as 2716s.

Graham

 

[[email protected]]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

The 2708 requires two additional supply voltages, +12 and -5 in
addition to the +5 required by 2716 onwards. That's probably why most
programmers don't support it.

Should not be hard to make one though - I made a 2716 programmer in
high school, and you could probably do a 2708 if you got the extra
voltages. I used an 8255 I/O chip wired into an expansion memory
socket on my Z80 computer; but you could also hang the 8255 off a
parallel port as an I/O expander. Either that, or get a USB-connected
microcontroller with enough I/O pins. For programming you'll need a
VPP supply and something that can generate a pulse of the right width
- back then I didn't want to trust software timing, today you might.
Or you could use a 2716 in an adapter as the replacement and only have
to worry about accomplishing the readout.

 

[Bill Sudbrink]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

I have S-100 microcomputers capable of reading and writing 2708s. A couple
of them actually boot into monitors stored on 2708s. Not willing to sell,
but if you are in the Washington, DC area, I would be happy to dump and/or
program some for you. email me if interested.

Bill Sudbrink

 

[Spehro Pefhany]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader..
It's very difficult to find modern eprom programmers that do this!
I have buyed a willeim but it does everithing but 2708!!
Well if it's possible i would make one.
I'm very good skinned as electronic handy man , but i can't know how to make
it.
Can someone help me?
And if someone got an old eprom programmer let me know!

The 2708 is similar to larger, newer EPROMs except for the extra
supply voltages, for reading.

However, IIRC, it uses a different programming algorithm where you are
supposed to cycle through the entire memory a number of times.

This thing is pretty old, thirty-plus years.

Best regards,
Spehro Pefhany

 

[JA]

The Andromeda Research EPROM+ programmer can handle the 2708. Price is
reasonable at US $289 plus shipping.

Fantastic work! I have contacted them!
I think that i will buy this!

 

[JA]

2. use a 2716 in an adapter socket to replace it, ground the 2716's

highest
address pin.
Unless you really want to keep it 'vintage'...

Yes , that's the point, i don't wanna to modify all my equipement!

 

[JeffM]

The 2708 is similar to larger, newer EPROMs
except for the extra supply voltages, for reading.

However, IIRC, it uses a different programming algorithm
where you are supposed to cycle through the entire memory
a number of times.

The differences between the 2708 EPROM
and the next device in the series:

2708 2716
+----\/----+ ---+
1 |A7 24| VCC | VCC
2 |A6 23| A8 | A8
3 |A5 22| A9 | A9
4 |A4 21| VBB | VPP (-5V on 2708)
5 |A3 20| WE/CS | /OE
6 |A2 19| VDD | A10 (-12V on 2708)
7 |A1 18| VPP | /CE
8 |A0 17| D7 | D7
9 |D0 16| D6 | D6
10 |D1 15| D5 | D5
11 |D2 14| D4 | D4
12 |GND 13| D3 | D3
+----------+ ---+

ASCII pinouts from:
http://www.embeddedlinks.com/chipdir/giicm/2716.txt
http://www.embeddedlinks.com/chipdir/giicm/2708.txt

2708 2716
+--------\/--------+ +--------------+
1 -|a7 vcc|- 24 A7 |1 +--+ 24| VCC
2 -|a6 a8|- 23 A6 |2 23| A8
3 -|a5 a9|- 22 A5 |3 22| A9
4 -|a4 vbb|- 21 A4 |4 21| VPP
5 -|a3 we/cs|- 20 A3 |5 20| /OE
6 -|a2 2708 vdd|- 19 A2 |6 19| A10
7 -|a1 program|- 18 A1 |7 2716 18| /CE
8 -|a0 o7|- 17 A0 |8 17| D7
9 -|o0 o6|- 16 D0 |9 16| D6
10 -|o1 o5|- 15 D1 |10 15| D5
11 -|o2 o4|- 14 D2 |11 14| D4
12 -|gnd o3|- 13 GND |12 13| D3
+------------------+ +--------------+

 

[Rich Grise]

hi guys!
I need to have an obsolete 2708 eprom programmer-reader.. It's very
difficult to find modern eprom programmers that do this! I have buyed a
willeim but it does everithing but 2708!! Well if it's possible i would
make one. I'm very good skinned as electronic handy man , but i can't know
how to make it.
Can someone help me?
And if someone got an old eprom programmer let me know!

Are you stuck with the three-supply 2708? They're a nightmare to program,
unless you have the programmer; I wouldn't recommend trying to build one.

Why not pick a 1KX8 chip that's a little more modern, like flash? I hear
they're relatively easy to program; you could use a bigger one by just
ignoring part of the address space.

Tood Luck!
Rich

 

[Rich Grise]

Yes i'm doing this in the last 2 months!

Exaclty! I'm monitorizing ebay.com ebay.de ebay.fr and ebay.it

But no luck, just modern type eprom , from 2716 and up!

This doesn't make any sense. Are you _specifying_ a PROM, or are you
stuck with the ones you have on hand?

Otherwise, why would you want to buy such an old clunker of a chip?

School assignment? >:->

Thanks,
Rich