Hi:
How about using a header socket and
installing eight 1N914 or 1N4148 diodes on it?
Ron
-----Original Message-----
From: n8vem...@googlegroups.com
[mailto:n8vem...@googlegroups.com] On
Behalf Of Steven Feinsmith
Sent: Wednesday, September 17,
2014 9:33 PM
To: n8vem...@googlegroups.com
Subject: [N8VEM-S100:5227] Re:
Ithaca Intersystems DPS-1 Front Panel
After few hours of research and seem possible found
diode array with compatible pin to pin. The component made by Microsemi. Part
number is 1N6508, isolated diode array and packed as 14-Pin ceramic DIP. The
article stated "For use as steering diodes protecting up to eight I/O
ports from ESD, EFT, or surge by directing them to the positive side of the
power supply line and to ground. An external TVS diode may be added between the
positive supply line and ground to prevent overvoltage on the supply rail."
Then I searched vendors and learned that part was not available anywhere even
eBay. I suspected this part was for military grade component. I will call
Microsemi tomorrow afternoon to see if I could obtain the component.
Enclosed a copy of datasheet for you and tell me what do you think?
Thanks,
Steven
On Saturday, September 13, 2014 3:00:10 PM UTC-4, Steven Feinsmith wrote:
Hi
everyone,
I have very little documentation for Ithaca Intersystems DPS-1 system. This
device was last manufactured before S-100 become obsolete due to Apple and IBM
hit the market in 1980's. The front panel for DPS-1 system was one of the best
designed. Nowdays, there were impossible to find it. I reviewed components that
used for the front panel were available from varies sources.
But one component, IC7 as labelled as "Diode Pack". I realized there
was no information about it. I looked the schematic showed "HEADER"
contained D0-D7 (Data Bus) to AM25LS2521PC, Eight Bit Equal To Comparator (AM =
Advanced Micro Devices) connected for Data Breakpoint (Low) and Breakpoint
Enable (Low). Other side connected to front panel DATA switches. Between
"Header" and AM25LS2521PC, there are "Diode Pack" as IC7.
The "Diode Pack" hook up with D0-D7 bus, +5 volt and ground. That is
all what the schematic showed.
What do you think about inside the "Diode Pack". Perhaps array of
diodes? Perhaps pull-up or pull-down resistors?
I enclosed a manual, "A FRONT PANEL FOR THE S-100 BUS" by Ithaca
InterSystems, Inc, 1979. The company languished in the 1980's, not being part
of the domination of the IBM PC and PC clones. The company was dead for more
than 30 years ago. Hopefully, you have skill to find out what is inside of the
diode pack.
It would be nice for N8VEM group to create clone version of this wonderful
front panel. By the way, you know about "Header" is capable to run
16-bit system by add 8 data buses, more data switches and more data LEDs. IT
may sounds like a big challenge for us to create new generation of front panel
board. Good idea?
Thank you,
Steven
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