Installation manual

Page 4 Installation Instructions: AM-642 STOP Converter
Rev. A01
3. Attach the first connector of the new SCSI cable (not the CPU connector on the end) to the SCSI
connector on the AM-642. If you are using the Wide SCSI-2 bus, you need to use the provided
68- to 50-pin adapter (PRA-00259-00) between the SCSI cable and the AM-642.
4. Plug a 4-pin power connector from the power supply into the power connector on the AM-642. If
you don’t have any connectors available, use the “Y” power cable included in the AM-642 kit
(DWB-10265-01) to split power from one of the existing peripherals.
5. Attach the DWF-20782-00 retainer bracket to lock the AM-642 assembly in the card cage.
Installing the External Cables
1. Remove the I/O cover plate or paddle card from the top slot in the I/O rear panel.
2. Install the shielded cable-mounting bracket (DWF-20171-00) in the top slot of the I/O rear panel.
Position the bracket so the studs face away from any I/O paddle cards below it.
3. There are two external, 50-pin shielded cables included with the AM-642. One end of each cable
has a PC edge connector. Take the other end of one cable and slide it through the left slot of the
cable mounting bracket. Pin 1 of the cable, marked by a red stripe, should be toward the left.
Secure the cable grounding strap to the pair of studs on the bracket.
4. Take the other cable and slide it through the right slot of the bracket, with pin 1 to the left.
Again, the end with the PC edge connector stays outside the chassis. Secure one end of the cable
grounding strap to one stud on the bracket; attach the other to the bracket using a standard screw.
5. Reattach the I/O panel to the AM-990 chassis.
6. Route the two cables into the card cage and over the AM-642. Plug the left cable into J2 on the
AM-642; plug the right cable into J1. Make sure the red stripe on each cable is properly matched
to pin 1 on its connector.
7. Connect the other ends of the cables to the mag tape drive. Attach the left cable to P2 on the
drive and the right cable to P1. Label the cables so you can reconnect them properly if needed in
the future.
Finishing Up
You have now finished installing the AM-642. Reinstall the card cage cover, side panel, and top cover as
described in the AM-990 Service Manual.
ATTACHING THE AM-642 EXTERNALLY
To ensure proper operation of an external AM-642 subsystem (PDB-00642-00) on an AMOS computer,
you must be very careful about exactly how it is connected to the SCSI bus. Proper bus termination, as
discussed below, is critical to reliable AM-642 operation.
The AM-642 is a narrow SCSI device. As with any narrow device, if you want to attach it to the
Wide SCSI-2 bus, you need to use a 68 to 50-pin adapter, available from Alpha Micro. Also,
because it is a narrow device, you cannot set its SCSI ID above 6, even though the Wide SCSI-2
bus supports IDs up to 15.