Peripherals; Cd-Rom Drive (Cdsk156) - Intergraph InterServe 8000 System Reference Manual

78
NOTE The AC OK signal is a TTL-compatible signal. It monotonically (without wavering) transitions to a high
level to indicate that the AC input power is within 90-132 VAC or 180-264 VAC. The signal provides
the 3 mA sink/source current as well as any current required for the LEDs. Provided that there is an
AC input, this signal must be available to report whether or not the outputs are functional. Overshoot
should be kept to less than 1 V above a maximum steady-state high-level output of 5 V. Undershoot
should be kept to less than -1 V below a minimum steady-state low-level output of 0 V.
NOTE The DC OK signal is a TTL-compatible signal, and its purpose is to initiate an orderly start-up
procedure under normal operating conditions. During power up, this signal should remain low (less
than 0.8 V) for at least 100 ms after all of the +5.1 V, +3.3 V, and +12 V outputs have reached their
minimum sense levels of 4.75 V, 3.14 V and 11.4 V, respectively. The signal then monotonically
(without wavering) transitions to a high level (greater than 2.4 V) to indicate that the power source is
stable. The signal provides the 3 mA sink/source current as well as any current required for the LEDs.
Overshoot should be kept to less than 1 V above a maximum steady-state high-level output of 5 V.
Undershoot should be kept to less than -1 V below a minimum steady-state low-level output of 0 V.

Peripherals

CD-ROM Drive (CDSK156)

The following figure shows the back of the CD-ROM drive.
Mode Select
Header
u
The SCSI connector uses MCBL204A and connects to J26 on the I/O expansion board. Refer to
the table "J26: MCBL204A, SCSI" on page 56 for the cable pinout.
u
Settings for mode select header, which sets SCSI ID, termination, parity, and other drive
functionality are printed on the CD-ROM drive. Default SCSI ID for the drive is 4 and
termination is disabled. Termination is provided by the SCSI cable. The following table shows
the SCSI ID selection:
SCSI ID
0
1
2
3
4
5
6
u
The power connector uses MCBL206A power supply cable from the power distribution board.
See the table "J22: MCBL206A, CD-ROM Drive and Floppy Disk Drive" on page 68 the for
pinout.
SCSI
Connector
ID1 ID2 ID4
Off Off Off
On Off Off
Off On Off
On On Off
Off Off On
On Off On
Off On On
Power
Connector