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RAM BOARD CHECKOUT
The following checkout procedure should be followed for a newly
assembled board.
It can also be used to diagnose problems in
previously operational boards.
The following terms are used in specifying expected test results:
GND
LOW
HIGH
+5V
AC
ground, 0 volts DC
logic zero, 0-.7 volts, normally about .3 volts
logic one, 2.4-5.0 volts, normally about 3 volts
+5
vo~ts
from power supply
Signal with pulses (as opposed to DC signal)
When referring to the name of a signal from the schematic
drawings, if the signal is identified with a bar over its name,
then the name is followed by a slash (e.g., STORE/) in the
checkout instructions.
When describing an AC pulse, the notation
(±W,P) refers to a positive or negative pulse with a width of W
appearing with a period of P.
For example, a positive pulse with
width 120 nanoseconds appearing every 25 microseconds would be
described as (+120ns,25us).
See Appendix 1 for details on how to
detect pulse signals.
If an oscilloscope will be used to test the board, a "scope
gound" may be installed by soldering a "bridge" of jumper wire
between two of the three PC board holes that connect edge
connector pins 50 and 100 near location 13E.
Note that either of
the two regulator machine Screws can also be used for ground test
points.
C1.
If your S-100 bus computer has a control panel, then check
out control panel operation of the RAM-16-A as described in
this step.
Otherwise, skip to step C2.
A. Set the address select switches for the region where
the RAM-16-A will be used (refer to the Configuration
section for details).
B.
Wit~
the computer power off, install the RAM-16-A board
into the motherboard.
C. Using the control panel, attempt to deposit the zero
value in the first byte of each 4K address region on
the board.
Then examine these addresses.
If the
values examined are not all zero, then skip to step C3.
Otherwise, continue at step C2.
.
C2.
If you do not alreaqy have a working computer, then skip to
step C3.
Otherwise, set the address select switches for an
available 16K address region (see the Configuration
section).
Then, with the computer power off, install the
RAM-16-A board into the computer motherboard.
Now use a
15
North Star 16K RAM BOARD
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