MICROFORUM

Hi to all,
I have created detailed schematic diagram of backplane at HP9845B. The backplane has part number 09845-66502. It has four slots for external interfaces. On the board are TTL buffers for inputs- / outputs data. I would like know a communication between the data buffers and CPU.

find manual for RTC clock 98035. In this manual you find schematics. First page of the schematic is the interface. This interface is important for you. It comply with the backplane 09845-66502.
How to control your interface:
you need to use standard I/O HP Basic commands. If your interface uses a MCU, the MCU needs to decode the HP Basic commands. The I/O HP Basic commands are described in the I/O programming manual.