On Sun, 11 Feb 2007 11:28:33 -0500, Jamie
t wrote:

Joachim Wunder wrote:
On Sun, 11 Feb 2007 11:28:24 GMT, "Arfa Daily"
wrote:


No problem, at least we know what's going on now. I still would be reluctant
to believe that the bulb is going to have done anything directly to the
board, evn if it is connected to it by way of being relay switched. The
relay contacts are electrically isolated from the coil by virtue of
substantial mechanical separation.


That´s what I was convinced too up to the day when the bulb was blown
for the first time. Well, I´ll tell you something, I have one sheet of
paper which came with the PCB, but which only describes part of the
external connectors (i.e. actually only the ones which interface to
the motor on the backside of the PCB). The "funny" thing about is that
this sheet shows a very rough outline of the PCB´s external connectors
and mentions a fuse which is said to be there in the (N)eutral line of
the PCB´s power supply. Ha! I would be glad if there was that fuse
which is rated at 1A F(link). "F(link)" in German means with very
quick response time. And what do I see when I look at the backside of
the PCB? Ha! The manufacturer has simply left out the fuse and has
soldered a piece of wire instead of the fuse holder. Well done.
Fuse links don't need to be actual fuses that you recognize, they can
be special wire used, what looks like a resistor on the board or simply
a small foil path that is 2 half-moons with a small link of foil between
them..

Ack, Jamie. But look at
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg please. On the
upper right corner this is IMHO not more than just a plain wire. You
agree?

"Joachim Wunder" wrote in message
...

Ack, Jamie. But look at
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg please. On the
upper right corner this is IMHO not more than just a plain wire. You
agree?

IMO not a fuse, a jumper.

On Sun, 11 Feb 2007 20:37:47 +1100, Franc Zabkar
wrote:

On Sun, 11 Feb 2007 01:03:22 +0100, Joachim Wunder
put finger to keyboard and composed:

On Sat, 10 Feb 2007 10:27:49 +1100, Franc Zabkar
wrote:

On Fri, 09 Feb 2007 13:37:10 +0100, Joachim Wunder
put finger to keyboard and composed:

might the 16-pin IC a I2C maybe? If so, which
ones were commonly used to control an Intel 8748/8749 ?


I just uploaded seperate larger pics of the front and back side of the
PCB:

front side:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

back side:
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg

I am sorry to not have done that any earlier. On weekends I now have a
little more time to take better pics and start any systematical
diagnostic tests.

There appear to be 8 or so interconnect pins at the RHS of the 16-pin
IC. Can you trace them to the uC's pins? Do they go to the data bus,
ie pins 12 through 19?

As far as I can see Pins 12, 13 and 14 of the microcontroller are
connected to the interconnect pins at the RHS of the 16-pin IC.

Which pins are power and ground?

Pin 8 is V_SS (GND) and Pin 16 is V_DD (+5V) as far as I measured on
the 16-pin IC.

What is the IC
to the right of the relays?

That´s a PHILIPS CNY17-4 Optocoupler.

Which chip/component drives the relay
coils?

That´s actually a BC237B transistor each. They are hidden below the
piggyback PCB, unfortunately.


- Franc Zabkar

Thanks
Joachim

AFAICT, the 16-pin IC, if the piggyback PCB faithfully mimics the
pinout, has at least three outputs at pins 1,2,3, each of which drives
the base of a relay driver transistor. Each pin has a pullup resistor
to Vcc, so I suspect that the outputs may be open collector.

Since pins 10,11,12,13 of the IC are connected to the uC's data bus, I
suspect that they may be inputs. If so, then I believe that these
inputs would need to be latched. The fact that there is a "VOH" on the
body of the chip suggests that it might be programmed, in which case
it could be a PAL.

- Franc Zabkar

While the PCB is resting silently in front of me and is connected to
+12V (and to +5V via a voltage regulator on the PCB) the 16-pin IC
shows up with the following readings (directly measure on the IC´s
pins):

Pin 1: Low , 0.000 kHz, 0.231 V
Pin 2: Low , 0.000 kHz, 0.167 V
Pin 3: Low , 0.000 kHz, 0.230 V
Pin 4: ----, 0.050 kHz, 3.468 V
Pin 5: High, 0.000 kHz, 4.979 V
Pin 6: High, 0.000 kHz, 4.979 V
Pin 7: Low , 0.000 kHz, 0.202 V
Pin 8: Vss (GND)
Pin 9: Low , 0.000 kHz, 0.204 V
Pin 10: High, 0.111 kHz, 4.971 V (frequency slightly alternating
around this frequency of 0.111 kHz)
Pin 11: Low , 0.000 kHz, 0.012 V
Pin 12: Low , 0.000 kHz, 0.012 V
Pin 13: ----, 0.000 kHz, 3.335 V
Pin 14: High, ?.??? kHz, 4.987 V (frequency randomly alternating from
0.000 kHz to more than 2 MHz)
Pin 15: Low , 0.000 kHz, 0.000 V
Pin 16: High, 0.000 kHz, 4.984 V

So, is there anything useful which could be derived from these values?
I.e. do these values still tend you to say that it could be a PAL?

Thanks a mil, again
Joachim

On Sun, 11 Feb 2007 20:08:48 GMT, "Homer J Simpson"
wrote:


"Joachim Wunder" wrote in message
.. .

Ack, Jamie. But look at
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg please. On the
upper right corner this is IMHO not more than just a plain wire. You
agree?

IMO not a fuse, a jumper.


Well, if you look at the upper left corner on the frontside of the PCB
you´ll see nothing that looks any similar to a jumper:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg .Only a few
drilled small holes. But anyway, there is nothing which could have
protected the circuitry of the PCB on the (N)eutral side of power
supply (230V AC). Nice manufacturer, I know...

"Joachim Wunder" wrote in message
...

Well, if you look at the upper left corner on the frontside of the PCB
you´ll see nothing that looks any similar to a jumper:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg .Only a few
drilled small holes. But anyway, there is nothing which could have
protected the circuitry of the PCB on the (N)eutral side of power
supply (230V AC). Nice manufacturer, I know...

The daughter board is a big red flag that this model has had modifications
from the original design. My guess is that there were several variations
possible with this circuit board and that still wasn't enough.

On Sun, 11 Feb 2007 21:11:47 GMT, "Homer J Simpson"
wrote:


"Joachim Wunder" wrote in message
.. .

Well, if you look at the upper left corner on the frontside of the PCB
you´ll see nothing that looks any similar to a jumper:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg .Only a few
drilled small holes. But anyway, there is nothing which could have
protected the circuitry of the PCB on the (N)eutral side of power
supply (230V AC). Nice manufacturer, I know...

The daughter board is a big red flag that this model has had modifications
from the original design. My guess is that there were several variations
possible with this circuit board and that still wasn't enough.


I fear that, too. *long sigh*

Anyway, does anybody know which special type of 680 Ohm resistor this
red resistor on the upper right corner of the PCB´s frontside is? :
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

"Joachim Wunder" wrote in message
...

Anyway, does anybody know which special type of 680 Ohm resistor this
red resistor on the upper right corner of the PCB´s frontside is? :
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

Probably a 1 or 2 W wire wound.

On Sat, 10 Feb 2007 23:27:52 +0100, Joachim Wunder
wrote:

No, I didn´t tried them yet. But I have done some good progress today:
After a whole bunch of further phone calls I was now finally able to
find out the manufacturer of the PCB. It´s a very small company in
Saar/Northern Germany. They are not on the Web, so you simply can´t
find them there, unfortunately. But the company who installed the
garage door opener back in 1990 had a deeper look into their archive
to find out this small company for me, again. Thanks God. Well, even
this company is located in Northern Germany but not presented on the
Web at all. So, life sometimes really sucks, I know.

Well, unfortunately, the techie himself who designed the PCB wasn´t in
today, but another tech person of the same company told me that they
MIGHT have some spare PCB still in stock. Thanks God. But this is only
an assumption and cannot be clarified before the upcoming Monday. So,
I will keep you all posted here. And, moreover, the techie whom I
had on the phone today even told me that all employees are definitely
not authorized to hand out any circuitry plans or specs/types of the
microcontroller and the accompanying IC. Holy cow.... anyway...
there´s some hope the next Monday. I´ll report back and keep you all
posted with an update then.

Hi guys, some drawback today. Oh, well... even the right techie was in
today, it´s still not clear whether they have an absolut 100%
compatible PCB still in stock for me. They said they need at least 1
day or a few more to find that our for me. All PCBs they currently
have in stock (from the shelf, I mean) are equipped with much more
modern µC´s. And what I need is an absolute compatible PCB of course.

So, I will keep you posted about the outcome. But this may take some
more days. My apologies. But that´s all I have for an update today.
Hmm, I think I soon can start opening my own blog about this topic.
Oh, well.

Thanks again for all your kind support so far!
Joachim

"Joachim Wunder" wrote in message
...

And what I need is an absolute compatible PCB of course.

Or one that can be easily hacked to work.

Hi Franc et al,

first of all my apologies for not being able to reply any earlier to
this thread with an update. My deepest apologies. Meanwhile I got a
spare PCB for the garage door opener which has no need for any
piggyback PCB any longer. Thanks God! The 8748 of the old PCB is still
alive as well. I was able to access its EPROM contents. Sorry that it
took me so long, but getting access to an 8748 adapter for my old ISA
EPROM programming card was a real challenge to me. But that´s another
story...

Anyway, the new PCB looks very similar to the old one:

front side of the new PCB:
http://img143.imageshack.us/img143/1120/cimg0131kd8.jpg

back side of the new PCB:
http://img68.imageshack.us/img68/4202/cimg0128ms3.jpg

Franc, you already were so kind as to start to track down the logics
of the 16-pin IC a couple of time ago (see text below). I am still
stuck in finding out the exact type of this logic IC. And, believe me,
I have already looked up hundreds of different datasheets at
www.datasheetarchive.com. Hmpf. The manufacturer of the PCB is still
not able (or should I better say willing...) to reveal the exact type
of this IC. But they told me that it´s definitely no PAL. What is
known to me is the following pin assignment:

Pin 1: Output, controls the basis of the transistor which in turn
controls GND of relay no. 3
Pin 2: Output, controls the basis of the transistor which in turn
controls GND of relay no. 2
Pin 3: Output, controls the basis of the transistor which in turn
controls GND of relay no. 1
Pin 4: Output, controls GND pin of the LED
Pin 5: NC
Pin 6: NC
Pin 7: NC
Pin 8: GND
Pin 9: NC
Pin 10: Input, connected to pin DB2 of 8748 µC
Pin 11: Input, connected to pin DB1 of 8748 µC
Pin 12: Input, connected to pin DB0 of 8748 µC
Pin 13: ?
Pin 14: ?
Pin 15: connected to GND
Pin 16: V_cc (+5V)

I hope you, Franc, and/or anyone else here has a good idea of which
logic IC this might be?

Thank you so much in advance.
Joachim


On Sun, 11 Feb 2007 20:37:47 +1100, Franc Zabkar
wrote:

On Sun, 11 Feb 2007 01:03:22 +0100, Joachim Wunder
put finger to keyboard and composed:

On Sat, 10 Feb 2007 10:27:49 +1100, Franc Zabkar
wrote:

On Fri, 09 Feb 2007 13:37:10 +0100, Joachim Wunder
put finger to keyboard and composed:

might the 16-pin IC a I2C maybe? If so, which
ones were commonly used to control an Intel 8748/8749 ?


I just uploaded seperate larger pics of the front and back side of the
PCB:

front side:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

back side:
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg

I am sorry to not have done that any earlier. On weekends I now have a
little more time to take better pics and start any systematical
diagnostic tests.

There appear to be 8 or so interconnect pins at the RHS of the 16-pin
IC. Can you trace them to the uC's pins? Do they go to the data bus,
ie pins 12 through 19?

As far as I can see Pins 12, 13 and 14 of the microcontroller are
connected to the interconnect pins at the RHS of the 16-pin IC.

Which pins are power and ground?

Pin 8 is V_SS (GND) and Pin 16 is V_DD (+5V) as far as I measured on
the 16-pin IC.

What is the IC
to the right of the relays?

That´s a PHILIPS CNY17-4 Optocoupler.

Which chip/component drives the relay
coils?

That´s actually a BC237B transistor each. They are hidden below the
piggyback PCB, unfortunately.


- Franc Zabkar

Thanks
Joachim

AFAICT, the 16-pin IC, if the piggyback PCB faithfully mimics the
pinout, has at least three outputs at pins 1,2,3, each of which drives
the base of a relay driver transistor. Each pin has a pullup resistor
to Vcc, so I suspect that the outputs may be open collector.

Since pins 10,11,12,13 of the IC are connected to the uC's data bus, I
suspect that they may be inputs. If so, then I believe that these
inputs would need to be latched. The fact that there is a "VOH" on the
body of the chip suggests that it might be programmed, in which case
it could be a PAL.

- Franc Zabkar

I think from today´s day I can answer my question myself: It´s a
74ALS188 according to the PCB´s manufacturer. Does anyone know where
to still get such ancient PROMs and where to get an affordable
programmer for it as well?

TIA,
Joachim.

On Tue, 27 Mar 2007 02:31:22 +0200, Joachim Wunder
wrote:

Hi Franc et al,

first of all my apologies for not being able to reply any earlier to
this thread with an update. My deepest apologies. Meanwhile I got a
spare PCB for the garage door opener which has no need for any
piggyback PCB any longer. Thanks God! The 8748 of the old PCB is still
alive as well. I was able to access its EPROM contents. Sorry that it
took me so long, but getting access to an 8748 adapter for my old ISA
EPROM programming card was a real challenge to me. But that´s another
story...

Anyway, the new PCB looks very similar to the old one:

front side of the new PCB:
http://img143.imageshack.us/img143/1120/cimg0131kd8.jpg

back side of the new PCB:
http://img68.imageshack.us/img68/4202/cimg0128ms3.jpg

Franc, you already were so kind as to start to track down the logics
of the 16-pin IC a couple of time ago (see text below). I am still
stuck in finding out the exact type of this logic IC. And, believe me,
I have already looked up hundreds of different datasheets at
www.datasheetarchive.com. Hmpf. The manufacturer of the PCB is still
not able (or should I better say willing...) to reveal the exact type
of this IC. But they told me that it´s definitely no PAL. What is
known to me is the following pin assignment:

Pin 1: Output, controls the basis of the transistor which in turn
controls GND of relay no. 3
Pin 2: Output, controls the basis of the transistor which in turn
controls GND of relay no. 2
Pin 3: Output, controls the basis of the transistor which in turn
controls GND of relay no. 1
Pin 4: Output, controls GND pin of the LED
Pin 5: NC
Pin 6: NC
Pin 7: NC
Pin 8: GND
Pin 9: NC
Pin 10: Input, connected to pin DB2 of 8748 µC
Pin 11: Input, connected to pin DB1 of 8748 µC
Pin 12: Input, connected to pin DB0 of 8748 µC
Pin 13: ?
Pin 14: ?
Pin 15: connected to GND
Pin 16: V_cc (+5V)

I hope you, Franc, and/or anyone else here has a good idea of which
logic IC this might be?

Thank you so much in advance.
Joachim


On Sun, 11 Feb 2007 20:37:47 +1100, Franc Zabkar
wrote:

On Sun, 11 Feb 2007 01:03:22 +0100, Joachim Wunder
put finger to keyboard and composed:

On Sat, 10 Feb 2007 10:27:49 +1100, Franc Zabkar
wrote:

On Fri, 09 Feb 2007 13:37:10 +0100, Joachim Wunder
put finger to keyboard and composed:

might the 16-pin IC a I2C maybe? If so, which
ones were commonly used to control an Intel 8748/8749 ?


I just uploaded seperate larger pics of the front and back side of the
PCB:

front side:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

back side:
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg

I am sorry to not have done that any earlier. On weekends I now have a
little more time to take better pics and start any systematical
diagnostic tests.

There appear to be 8 or so interconnect pins at the RHS of the 16-pin
IC. Can you trace them to the uC's pins? Do they go to the data bus,
ie pins 12 through 19?

As far as I can see Pins 12, 13 and 14 of the microcontroller are
connected to the interconnect pins at the RHS of the 16-pin IC.

Which pins are power and ground?

Pin 8 is V_SS (GND) and Pin 16 is V_DD (+5V) as far as I measured on
the 16-pin IC.

What is the IC
to the right of the relays?

That´s a PHILIPS CNY17-4 Optocoupler.

Which chip/component drives the relay
coils?

That´s actually a BC237B transistor each. They are hidden below the
piggyback PCB, unfortunately.


- Franc Zabkar

Thanks
Joachim

AFAICT, the 16-pin IC, if the piggyback PCB faithfully mimics the
pinout, has at least three outputs at pins 1,2,3, each of which drives
the base of a relay driver transistor. Each pin has a pullup resistor
to Vcc, so I suspect that the outputs may be open collector.

Since pins 10,11,12,13 of the IC are connected to the uC's data bus, I
suspect that they may be inputs. If so, then I believe that these
inputs would need to be latched. The fact that there is a "VOH" on the
body of the chip suggests that it might be programmed, in which case
it could be a PAL.

- Franc Zabkar

"Joachim Wunder" schreef in bericht
...
On Tue, 27 Mar 2007 02:31:22 +0200, Joachim Wunder
wrote:

Hi Franc et al,

first of all my apologies for not being able to reply any earlier to
this thread with an update. My deepest apologies. Meanwhile I got a
spare PCB for the garage door opener which has no need for any
piggyback PCB any longer. Thanks God! The 8748 of the old PCB is still
alive as well. I was able to access its EPROM contents. Sorry that it
took me so long, but getting access to an 8748 adapter for my old ISA
EPROM programming card was a real challenge to me. But that´s another
story...

Anyway, the new PCB looks very similar to the old one:

front side of the new PCB:
http://img143.imageshack.us/img143/1120/cimg0131kd8.jpg

back side of the new PCB:
http://img68.imageshack.us/img68/4202/cimg0128ms3.jpg

Franc, you already were so kind as to start to track down the logics
of the 16-pin IC a couple of time ago (see text below). I am still
stuck in finding out the exact type of this logic IC. And, believe me,
I have already looked up hundreds of different datasheets at
www.datasheetarchive.com. Hmpf. The manufacturer of the PCB is still
not able (or should I better say willing...) to reveal the exact type
of this IC. But they told me that it´s definitely no PAL. What is
known to me is the following pin assignment:

Pin 1: Output, controls the basis of the transistor which in turn
controls GND of relay no. 3
Pin 2: Output, controls the basis of the transistor which in turn
controls GND of relay no. 2
Pin 3: Output, controls the basis of the transistor which in turn
controls GND of relay no. 1
Pin 4: Output, controls GND pin of the LED
Pin 5: NC
Pin 6: NC
Pin 7: NC
Pin 8: GND
Pin 9: NC
Pin 10: Input, connected to pin DB2 of 8748 µC
Pin 11: Input, connected to pin DB1 of 8748 µC
Pin 12: Input, connected to pin DB0 of 8748 µC
Pin 13: ?
Pin 14: ?
Pin 15: connected to GND
Pin 16: V_cc (+5V)

I hope you, Franc, and/or anyone else here has a good idea of which
logic IC this might be?

Thank you so much in advance.
Joachim


On Sun, 11 Feb 2007 20:37:47 +1100, Franc Zabkar
wrote:

On Sun, 11 Feb 2007 01:03:22 +0100, Joachim Wunder
put finger to keyboard and composed:

On Sat, 10 Feb 2007 10:27:49 +1100, Franc Zabkar
wrote:

On Fri, 09 Feb 2007 13:37:10 +0100, Joachim Wunder
put finger to keyboard and composed:

might the 16-pin IC a I2C maybe? If so, which
ones were commonly used to control an Intel 8748/8749 ?


I just uploaded seperate larger pics of the front and back side of the
PCB:

front side:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

back side:
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg

I am sorry to not have done that any earlier. On weekends I now have a
little more time to take better pics and start any systematical
diagnostic tests.

There appear to be 8 or so interconnect pins at the RHS of the 16-pin
IC. Can you trace them to the uC's pins? Do they go to the data bus,
ie pins 12 through 19?

As far as I can see Pins 12, 13 and 14 of the microcontroller are
connected to the interconnect pins at the RHS of the 16-pin IC.

Which pins are power and ground?

Pin 8 is V_SS (GND) and Pin 16 is V_DD (+5V) as far as I measured on
the 16-pin IC.

What is the IC
to the right of the relays?

That´s a PHILIPS CNY17-4 Optocoupler.

Which chip/component drives the relay
coils?

That´s actually a BC237B transistor each. They are hidden below the
piggyback PCB, unfortunately.


- Franc Zabkar

Thanks
Joachim

AFAICT, the 16-pin IC, if the piggyback PCB faithfully mimics the
pinout, has at least three outputs at pins 1,2,3, each of which drives
the base of a relay driver transistor. Each pin has a pullup resistor
to Vcc, so I suspect that the outputs may be open collector.

Since pins 10,11,12,13 of the IC are connected to the uC's data bus, I
suspect that they may be inputs. If so, then I believe that these
inputs would need to be latched. The fact that there is a "VOH" on the
body of the chip suggests that it might be programmed, in which case
it could be a PAL.

- Franc Zabkar

I think from today´s day I can answer my question myself: It´s a
74ALS188 according to the PCB´s manufacturer. Does anyone know where
to still get such ancient PROMs and where to get an affordable
programmer for it as well?

TIA,
Joachim.


Ever used the old 74S88 in a fast (at the time) control application. The
74ALS188 is one of the same family of 32x8 bit PROMS. I've only the pinout,
no datasheet anymore. Even in the old days the device was hard to find. If
you can find them now, I guess they will have a price...
But once you know the contents, you can program it's logical function in
another device like a PAL. Which will be the function of the piggyback on
the old PCB. You may be able to use an EPROM or an EEPROM as well. I
remember those "fast" 74S88 had an accesstime of 50ns. Modern (E)EPROMS are
faster.

petrus bitbyter

On Tue, 27 Mar 2007 20:33:43 +0200, "petrus bitbyter"
wrote:


"Joachim Wunder" schreef in bericht
.. .
On Tue, 27 Mar 2007 02:31:22 +0200, Joachim Wunder
wrote:

Hi Franc et al,

first of all my apologies for not being able to reply any earlier to
this thread with an update. My deepest apologies. Meanwhile I got a
spare PCB for the garage door opener which has no need for any
piggyback PCB any longer. Thanks God! The 8748 of the old PCB is still
alive as well. I was able to access its EPROM contents. Sorry that it
took me so long, but getting access to an 8748 adapter for my old ISA
EPROM programming card was a real challenge to me. But that´s another
story...

Anyway, the new PCB looks very similar to the old one:

front side of the new PCB:
http://img143.imageshack.us/img143/1120/cimg0131kd8.jpg

back side of the new PCB:
http://img68.imageshack.us/img68/4202/cimg0128ms3.jpg

Franc, you already were so kind as to start to track down the logics
of the 16-pin IC a couple of time ago (see text below). I am still
stuck in finding out the exact type of this logic IC. And, believe me,
I have already looked up hundreds of different datasheets at
www.datasheetarchive.com. Hmpf. The manufacturer of the PCB is still
not able (or should I better say willing...) to reveal the exact type
of this IC. But they told me that it´s definitely no PAL. What is
known to me is the following pin assignment:

Pin 1: Output, controls the basis of the transistor which in turn
controls GND of relay no. 3
Pin 2: Output, controls the basis of the transistor which in turn
controls GND of relay no. 2
Pin 3: Output, controls the basis of the transistor which in turn
controls GND of relay no. 1
Pin 4: Output, controls GND pin of the LED
Pin 5: NC
Pin 6: NC
Pin 7: NC
Pin 8: GND
Pin 9: NC
Pin 10: Input, connected to pin DB2 of 8748 µC
Pin 11: Input, connected to pin DB1 of 8748 µC
Pin 12: Input, connected to pin DB0 of 8748 µC
Pin 13: ?
Pin 14: ?
Pin 15: connected to GND
Pin 16: V_cc (+5V)

I hope you, Franc, and/or anyone else here has a good idea of which
logic IC this might be?

Thank you so much in advance.
Joachim


On Sun, 11 Feb 2007 20:37:47 +1100, Franc Zabkar
wrote:

On Sun, 11 Feb 2007 01:03:22 +0100, Joachim Wunder
put finger to keyboard and composed:

On Sat, 10 Feb 2007 10:27:49 +1100, Franc Zabkar
wrote:

On Fri, 09 Feb 2007 13:37:10 +0100, Joachim Wunder
put finger to keyboard and composed:

might the 16-pin IC a I2C maybe? If so, which
ones were commonly used to control an Intel 8748/8749 ?


I just uploaded seperate larger pics of the front and back side of the
PCB:

front side:
http://img184.imageshack.us/img184/3231/cimg0083kj3.jpg

back side:
http://img187.imageshack.us/img187/1555/cimg0084qg6.jpg

I am sorry to not have done that any earlier. On weekends I now have a
little more time to take better pics and start any systematical
diagnostic tests.

There appear to be 8 or so interconnect pins at the RHS of the 16-pin
IC. Can you trace them to the uC's pins? Do they go to the data bus,
ie pins 12 through 19?

As far as I can see Pins 12, 13 and 14 of the microcontroller are
connected to the interconnect pins at the RHS of the 16-pin IC.

Which pins are power and ground?

Pin 8 is V_SS (GND) and Pin 16 is V_DD (+5V) as far as I measured on
the 16-pin IC.

What is the IC
to the right of the relays?

That´s a PHILIPS CNY17-4 Optocoupler.

Which chip/component drives the relay
coils?

That´s actually a BC237B transistor each. They are hidden below the
piggyback PCB, unfortunately.


- Franc Zabkar

Thanks
Joachim

AFAICT, the 16-pin IC, if the piggyback PCB faithfully mimics the
pinout, has at least three outputs at pins 1,2,3, each of which drives
the base of a relay driver transistor. Each pin has a pullup resistor
to Vcc, so I suspect that the outputs may be open collector.

Since pins 10,11,12,13 of the IC are connected to the uC's data bus, I
suspect that they may be inputs. If so, then I believe that these
inputs would need to be latched. The fact that there is a "VOH" on the
body of the chip suggests that it might be programmed, in which case
it could be a PAL.

- Franc Zabkar

I think from today´s day I can answer my question myself: It´s a
74ALS188 according to the PCB´s manufacturer. Does anyone know where
to still get such ancient PROMs and where to get an affordable
programmer for it as well?

TIA,
Joachim.


Ever used the old 74S88 in a fast (at the time) control application. The
74ALS188 is one of the same family of 32x8 bit PROMS. I've only the pinout,
no datasheet anymore. Even in the old days the device was hard to find. If
you can find them now, I guess they will have a price...
But once you know the contents, you can program it's logical function in
another device like a PAL. Which will be the function of the piggyback on
the old PCB. You may be able to use an EPROM or an EEPROM as well. I
remember those "fast" 74S88 had an accesstime of 50ns. Modern (E)EPROMS are
faster.

petrus bitbyter


Yes, Petrus, I am having hell of a problem here in Germany to still
find an equivalent to the 74ALS188. No solution yet. On the other
hand, I don´t know how critical accesstime is for the 8748 code which
is currently stored in the EPROM of the 8748. I guess finding that out
wouldn´t be easy without disassembling the code (which I have already
done, of course ) and understanding the full code.

So, if anyone here still has any unused 74ALS188 in stock, please let
me know and drop me an offer for them. Paying via PayPal preferred.

On Tue, 27 Mar 2007 21:26:36 +0200, Joachim Wunder
put finger to keyboard and composed:

Yes, Petrus, I am having hell of a problem here in Germany to still
find an equivalent to the 74ALS188. No solution yet. On the other
hand, I don´t know how critical accesstime is for the 8748 code which
is currently stored in the EPROM of the 8748. I guess finding that out
wouldn´t be easy without disassembling the code (which I have already
done, of course ) and understanding the full code.

So, if anyone here still has any unused 74ALS188 in stock, please let
me know and drop me an offer for them. Paying via PayPal preferred.

I have an N82S123 32x8 PROM. It's a 3-state type rather than open
collector (N82S23), but I believe that it is otherwise functionally
identical. Maybe all that you will need to make it work are pullup
resistors ???

Anyway, if it suits your needs you can have it for the cost of postage
from Australia. I can also program it for you.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On Wed, 28 Mar 2007 07:02:06 +1000, Franc Zabkar
wrote:

On Tue, 27 Mar 2007 21:26:36 +0200, Joachim Wunder
put finger to keyboard and composed:

Yes, Petrus, I am having hell of a problem here in Germany to still
find an equivalent to the 74ALS188. No solution yet. On the other
hand, I don´t know how critical accesstime is for the 8748 code which
is currently stored in the EPROM of the 8748. I guess finding that out
wouldn´t be easy without disassembling the code (which I have already
done, of course ) and understanding the full code.

So, if anyone here still has any unused 74ALS188 in stock, please let
me know and drop me an offer for them. Paying via PayPal preferred.

I have an N82S123 32x8 PROM. It's a 3-state type rather than open
collector (N82S23), but I believe that it is otherwise functionally
identical. Maybe all that you will need to make it work are pullup
resistors ???

Anyway, if it suits your needs you can have it for the cost of postage
from Australia. I can also program it for you.

- Franc Zabkar

Thanks, Franc, for your kind offer. I guess I have just found a good
source in Germany for 74S188 from National. Hmmm, I am still curious
of which programmer you actually have. And, can any programmer even
copy an existing 74ALS188 if it (the programmer) can program an unused
74ALS188? Please pardon my stupidity, but except programming EPROMs
and 8748 I never did any 'acrobatics' with PROMs...

Joachim

On Tue, 27 Mar 2007 23:28:43 +0200, Joachim Wunder
put finger to keyboard and composed:

Thanks, Franc, for your kind offer. I guess I have just found a good
source in Germany for 74S188 from National. Hmmm, I am still curious
of which programmer you actually have.

I have an old Sunshine Expro-60.

And, can any programmer even
copy an existing 74ALS188 if it (the programmer) can program an unused
74ALS188? Please pardon my stupidity, but except programming EPROMs
and 8748 I never did any 'acrobatics' with PROMs...

Joachim

AFAIK these PROMS have no security bits so you should be able to read
their contents without any trouble. The 74S188 uses fusible link
technology which means it would require a different programming
algorithm than an EPROM, but accessing its data should be no
different.

BTW, what good is a device programmer that is unable to verify (ie
read and compare) the device it has just programmed? ;-)

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On Wed, 28 Mar 2007 08:29:49 +1000, Franc Zabkar
wrote:

On Tue, 27 Mar 2007 23:28:43 +0200, Joachim Wunder
put finger to keyboard and composed:

Thanks, Franc, for your kind offer. I guess I have just found a good
source in Germany for 74S188 from National. Hmmm, I am still curious
of which programmer you actually have.

I have an old Sunshine Expro-60.

Ah, ok. Don´t know this device, but must be powerful.


And, can any programmer even
copy an existing 74ALS188 if it (the programmer) can program an unused
74ALS188? Please pardon my stupidity, but except programming EPROMs
and 8748 I never did any 'acrobatics' with PROMs...

Joachim

AFAIK these PROMS have no security bits so you should be able to read
their contents without any trouble. The 74S188 uses fusible link

Yes, the same applied to my two 8748 (one on the old PCB and one on
the new PCB): No security bits, so I was able to read them out,
finally. Thanks God. The source codes (they slightly differ from
each other) both show a couple of the following opcodes:

movx a,@r1
movx @r1,a
movx a,@r0
movx @r0,a

That first confused me a little, ´cause these movx commands normally
reference external memory, but \RD and \WR pins of my 8748 are not
connected to anything on the PCB. Hmmmm, strange, isn´t it? The
74ALS188 is connected to port P0 (i.e. the BUS) of the 8748. So, the

outl bus,a
ins a,bus

commands seem obvious to me. Hmmm. Well, anyway, I am very satisfied
that the 8748´s EPROM content was readable at all.

technology which means it would require a different programming
algorithm than an EPROM, but accessing its data should be no
different.

OK. Sounds fine. Meanwhile I even google´d enough to know now more
about the programming algorithms for PROMs in general.


BTW, what good is a device programmer that is unable to verify (ie
read and compare) the device it has just programmed? ;-)

That´s absolutely right. ACK.

Kind regards,
Joachim