Integrated System Chec~Out - NorthStar HORIZON Manual

INTEGRATED SYSTEM CHECKOUT
You have now completely assembled the HORIZON mainframe,
processor board, RAM board, and disk controller board and cheeked
out these boards independently of each other as much as possible.
This section describes a step-by-step process for integrating
the major components of your system in a way designed to localize
any remaining problems.
II. Refer to the assembly instructions for your processor board
and configure the auto-jump address to be the disk
controller bootstrap PROM starting address (E800H).
12. Be sure the HORIZON power is off and then plug the processor
board into its motherboard connector (normally PI) and plug
the disk controller board into its motherboard connector
(normally P9). No other board should be plugged into the
motherboard at this time, and no diskette should be inserted
in the disk dr~ve(s). Connect the disk drive ribbon cable
as shown in figure 2C. Be sure the two PC boards are
properly seated in their edge connectors, and then turn
on the power. The disk drive motor(s) should turn on and
the red light on drive #1 should turn on. Then the motor(s)
should turn off after twelve seconds. If the motor(s) do
start, then proceed to step 13. Otherwise, if the motor(s)
do not turn on, continue this step as follows:
A. Depress and release the reset switch. If the motor(s) still
do not turn on, then proceed to part B. If the motor(s) now
turn on, then check the power sequencing circuitry on the
motherboard and the processor board. Proceed to step 13
after locating and correcting the problem.
B. Momentarily ground 12B pin 3 on the disk controller board by
briefly shorting it to 12B pin 7 with a piece of jumper
wire. If this causes the motor(s) to turn on, then remove
the wire and proceed to part C. If this does not cause the
motor(s) to turn on, then check the signal cable connections
to the disk drive and the power cable connections to the
disk drive. After locating and correcting the problem,
start over at the beginning of step 12.
C. Momentarily ground 13C pin 1 (MOTOR SET/) by briefly
shorting it to 13C pin 8 with a piece of jumper wire. The
motor(s) should turn on and then stay on for about 12
seconds after the wire is removed. If this succeeds, then
proceed to part D. If this does not succeed, then the
problem is with the counting circuitry on the disk
controller board. After locating and correcting the
problem, start over at step 12.
D. Turn off the power and remove the 74LS00 from location 7C.
Remove the 74LS08 from location 6C, bend pin 3 of the IC out
North Star HORIZON Computer 54