IBM Personal Computer

Power-On Self Test (POST)
If you have an expansion unit attached to your Personal
Computer, the expansion unit must
always be turned on
first unless otherwise indicated. If this is not done, an
error is indicated on the display. To recover, power
must be turned off
on all devices then power turned on
with the expansion unit being turned on before the
system unit.
When you first set the system unit's Power switch to
On a power-on self test (POST) occurs. The POST
takes 13
to 90 seconds depending on the amount of
memory installed.
1 Set the Power switch on the expansion unit (if
attached) to On.
2 Turn on all attached devices, then set the system
unit Power switch to On. There will normally
be
three responses: ~
A The cursor will appear on the screen in
approximately 4 seconds.
B One short beep will
be heard after the
memory
is tested.
C The IBM Personal Computer BASIC
message will appear
on the screen.
2-14 Setup