Thank you all!
I can't find where it says that Grub4dos can read the Syslinux menu format boot entries any more -- too many trials, and too many reboots have made it impossible for me to find it now.
Anyway, I've found a wonderful article that is on this exact topic, and I'm glad to be re-posting it here, from https://www.rmprepus...inload-syslinux. Guess who wrote it at the first place?
Convert a syslinux.cfg file to a menu.lst file
This is taken from a post
by Wonko the Sane (aka jaclaz)
Example syslinux/isolinux entry
append noapic initrd=images/pmagic/initramfs root=/dev/ram0 init=/linuxrc ramdisk_size=100000
When converted to grub4dos we get:
kernel /images/pmagic/bzImage noapic root=/dev/ram0 init=/linuxrc ramdisk_size=100000
label becomes title
The initrd command must be used to specify the initial ram filesystem loader file.
kernel remains kernel followed by the path to the kernel file
There is no direct equivalent to the append command in grub4dos, because grub4dos it parses ANYTHING after the kernel file, as parameters to be passed to the Linux kernel (same thing append does) but you need to remove the initrd parameter from the kernel parameter list.
After a grub4dos command there should be a space (and NOT an = sign, though it's parser allows it).
A file or device in grub4dos is always a "qualified" path, when you write /images/pmagic/bzImage you are actually writing ()/images/pmagic/bzImage or in "pseudocode" <current root>/images/pmagic/bzImage. Say that your current root is (pd), then by writing /images/pmagic/bzImage you are actually writing (pd)/images/pmagic/bzImage and of course if you omit the leading slash what you get makes NO sense (pd)images/pmagic/bzImage
WARNING: If the menu.lst is not working correctly, make sure you have the correct <cr><lf> characters between each line. If you have use Windows cut-and-paste to copy lines from a web page or from a syslinux or isolinux menu, you can often find that you have invisible characters in your menu.lst file. It may appear OK in Notepad but not in Notepad++. Verify that your menu.lst commands are OK, by running grub4dos and highlighting the menu entry you want to look at, then press e to edit the menu entry - check that the menu lines are correct and identical to the lines in your menu.lst file. This has happened to me several times when copying from a linux file to a standard text file!