Problems when booting a Fedora system embedded in a Canadian plotter
 

I have a plotter with an embedded Fedora 3.x. During boot, the system displays errors such as mount: can't open /etc/mtab, Input/Output Error several times, and then displays the message RealTime Clock Not Found. Please install RTC on Parallel Port and it stops here.

Welcome to LinuxQuestions.

Unfortunately, it is the step after the real time clock warning message that is causing the plotter to stop booting. Since this is an embedded system it may not be exactly configured like a typical desktop but the next steps would be to perform fsck checks on not root file systems which is unknown and then start specific run level processes.

Without knowing anything about the hardware there isn't much help we can provide.

I was thinking maybe BIOS battery. Has this plotter been in storage for a (good) while ?.

I was also thinking that the mtab warning could be due to failing hardware i.e. whatever physical medium the root filesystem resides.