IBM Personal Computer XT Manual To Operations page 50

POST will finish in 13 to 90 seconds, depending on the
amount of memory in your system. Normally, you will
receive the following responses:
A
Look in the upper left-hand corner of the screen
during POST.
If you have the Personal Computer, a blinking
cursor should appear.
"
...
' 1 '
If you have the Personal Computer XT, a number
should appear and continue to increase in value
until it equals the amount of memory in your
system.
XXX KB OK
30-2 Start April 1984