Ram Board Checkout - North Star RAM-16-A Manual

The following checkout procedure should be followed for a newly
assembled board.
previously operational boards.
The following terms are used in specifying expected test results:
GND ground, 0 volts DC
LOW logic zero, 0-.7 volts, normally about .3 volts
HIGH logic one, 2.4-5.0 volts, normally about 3 volts
+5 volts from power supply
+ 5V
AC 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/)
checkout instructions.
(-W,P) refers to a positive or negative pulse with a width of W
appearing with a period of P.
width 120 nanoseconds appearing every 25 microseconds would be
described as (+120ns,25us).
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.
the two regulator machine screws can also be used for ground test
points.
Cl. 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.
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. With 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.
values examined are not all zero, then skip to step C3.
Otherwise, continue at step C2.
C2. If you do not already have a working computer, then skip to
step C 3 . Otherwise, set the address select switches for an
available 16K address region (see the Configuration
section).
RAM-16-A board into the computer motherboard.
15

RAM BOARD CHECKOUT

It can also be used to diagnose problems in
When describing an AC pulse, the notation
For example, a positive pulse with
See Appendix 1 for details on how to
Otherwise, skip to step C2.
Then examine these addresses.
Then, with the computer power off, install the
North Star 16K RAM BOARD
in the
Note that either of
If the
Now use a