Although it would probably take a lot of work, remember that VirtualBox is actually open source and thus it’s possible to modify it.
I’ve never played around with the source, but still.
(I’ve played a bit with the source for 86box, in particular to allow freely setting the MAC address for some network cards that don’t allow changing the address fully. This is needed to correctly run DECNET as the MAC address directly translates to a DECNET address (i.e. four bytes of the MAC address is always the same for DECNET and the last two forms the DECNET address in the form of a 6+10 byte “pair”, allowing 63 networks with 1023 nodes each).
If you can use VirtualBox there is a huge performance win as compared to for example 86box as you don’t have to emulate the CPU with VirtualBox. (Best regards from Captain Obvious).

I know it’s so frustrating.

I ended up moving to qemu mostly as I could run it on a VPS.. although I’m not sure how much RAM it presents ..

It was an issue back then too going beyond 16Mb

in Virtual PC 2007 bios there is no souch setting (I think it uses some kind of AMI BIOS)

after switching to Virtualbox I don’t have souch problem (OS2 crashes if I increase RAM) anymore

What I did discover is that as soon as install LAN Manager Server, the next time I reboot OS2 it gets stuck in Loading Screen (even in Virtualbox) (like it wouldn’t like my network card driver os something)

BIOS sometimes had an OD/2 setting for more than 64Mb. Although I’m not sure you can get into the bios and see if it’s a setting, and if it’ll honor it.
OS/2 so needed a ‘mem’ command

I am trying to do make it act as RIPL boot server, but first the thing complained that I had to little ram (it needs at lest 256MB)

if I try to increase the ram in virtual pc 2007 past 64mb the os2 hangs (don’t even get to the logon screen)

There are some patches here: https://www.os2site.com/sw/upgrades/pcram.html
but they seam to only be for Warp 4, not OS2 2.1

If I ignore the scarry warning LAN Manager gives me about to little ram (since I only want to run RIPL server, and nothing else): https://images2.imgbox.com/6a/90/kNKC9QoO_o.png

I get it installed, but after a reboot it runs CHDSK hangs, then I rebbot again ang it hangs loading screen: https://images2.imgbox.com/6c/17/F4P9RmKM_o.png

OOPS I updated the link, it should have been OS2 not os2 in the file path.

Very sorry about that.

I don’t know if Windows 3.0 is designed to work with 64 MB of RAM installed under OS/2. I think that I better test it out. 🙂