M7504: DEQNA Ethernet adapter

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Picture 1: M7504 DEQNA module

The DEQNA is a thin/thickwire Ethernet adapter for the qbus. The network cable connection is via a filtered AUI port on a patch panel insert. The module contains three jumpers, three diagnostic LEDs and a BERG-type connector for the cable to the patch panel.

There are two standard CSR addresses for the DEQNA, which can be configured with jumper W1, which has three pins. With the jumper installed between the pin closer to the BERG connector and the one on the middle, the address is 17774460. Installing the jumper between the fatrher and the midle pin, the CSR is at 17774440. The interrupt vector is set by software, no hardware configuration required. Jumper W2 is for enabling DMA burst (If removed -which is the default- the DEQNA waits 5 usecs before re-requesting the bus, leaving enough bus time fo the other devices on the qbus). Jumper W3 is for disabling the sanity timer (default)

The DEQNA is not supported by VMS 5.0 or above. The m68000-based M7516 DELQA is the successor.

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Created by: Ákos Varga Last modified: