How-to question - limiting the number of kernels for each OS displayed in boot menu

[Bret Busby]

Hello.

I have a system where, in using the Legacy boot method, I at present
have Debian 7 and Debian 6 LTS and Ubuntu 14.04 LTS, installed.

When I boot the system, in the GRUB menu to select which operating
system to boot, I get more than one screen of options, as, for the
Ubuntu options, more than 10 lines of (presumably different kernel
versions) options to boot into Ubuntu, are displayed, and so, being
the last operating system installed, I have to go to a second screen,
to get to the option to boot into Debian 6 LTS.

I also want to try to install Ubuntu 12.04 LTS on the system, and to
have the option to boot into that, in order to try to discover
something.

from memory, a method used to be available, to configure GRUB, so
that, in the boot menu, no more than the last <x> number of kernel
versions, would be displyed (for example, no more than the last three
kernel versions would be displayed in the boot menu, for each
operating system found and listed).

I have viewed the manual  published at
http://www.gnu.org/software/grub/manual/grub.html
but I can not (easily) find how to achieve the configuration of the
GRUB boot menu, so as to limit the number of kernel versions for each
operating system, to be displayed in the GRUB boot menu.

I want to limit the number of kernel versions to be listed for each
operating system displayed, to be for only the three last kernel
versions, for each operating system.

If this can still be done in GRUB, please tell me how to do it,
stepwise, as I am apparently, relatively simple.

Thank you in anticipation.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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