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Ithaca Intersystems DPS-1 Front Panel

Hi everyone,

There were several front panel for S-100 computer system made in late of 1970's. The best and last designed front panel was Ithaca Intersystems DPS-1 computer before company languished in the early of 1980's, not being part of the domination of the IBM PC and PC clones. It was about thirty years ago.

I have few documentation for the DPS-1 front panel. I have schematic and checked every components. The components are available at various vendors. Even I have information on C&K switches but only that we may not able to find plastic toggles except if anyone have 3-D printing can re-create the plastic toggles even front molding.

I have full size TEI mainframe in the basement and it overhaul completed with new switch power supplies. I removed old linear power supply because of huge capacitors were too old and too expensive to replace it. I preferred to use switch power supply as described by Andrew Lynch (see http://www.s100computers.com/My%20System%20Pages/The%20Box/The%20Box.htm#The_Power_Supply). This was best method because the switch power supplies have short circuit/overload/over voltage protections.

Anyway, the front panel components were easy to obtain but realized only one component, IC7. The schematic stated it was "Diode Pack". This component connected data bus from "Header" to AM25LS2521PC, Eight Bit Equal To Comparator (AM = Advanced Micro Devices) and few other ICs. I never saw like this and wonder if it contained something like array of diodes along with pull-up or pull-down resistors because this component has +5V and Ground pins. Perhaps your skill and knowledge may able to know what it is and can create homemade circuit to replace the diode pack.

The schematic designed by "W. Stark". I tried to search for this person but no luck. Hopefully, that you and I can resolve this mystery component before I can able to duplicate this front panel board. Perhaps this first prototype will be run with 8-bit system but can upgrade to 16-bit system because "header" already have 8 extra pins as reserved for 16-bit system. Obviously, it may need some more components and switches and LEDs. Hopefully, you can consider to start this kind of project?

Thank you,


Attachment: Ithaca Intersystems Front Panel.pdf
Description: Adobe PDF document