How to overcome a boot-up endless loop?

[Josef Lowder]

Recently, I found a way to put my IBM Thinkpad T40 running PCLinuxOS
to sleep rather than turning it off by using:  apm -s

This has worked well for a couple of months with instant restarts
whenever I opened the lid ... until yesterday.  Something went amiss,
and when I tried to restart, I saw this repeating endlessly:

/etc/rc.d/rc.sysinit: line 1333: /bin/usleep: Input Output error

So, I tried rebooting ... same thing ... and now I can't get the
system to boot at all.

How can I recover from this?