document updated 14 years ago, on Mar 31, 2012
http://mbldr.sourceforge.net/
http://board.flatassembler.net/topic.php?t=11774
===== stage1 bootloaders that may not be difficult to modify ====
---- Grub4DOS ----
grldr.mbr already has some config bytes.... and it looks pretty handy in general
http://svn.gna.org/viewcvs/grub4dos/trunk/stage1/stage1.S?view=markup
---- GRUB2 ----
Why is booting from the VBR so discouraged? That isn't clear at all:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/445416