Ah, okay, I didn't know that, sorry. I choosed the generic type, because I assumed that
this famous anonymous XT BIOS would be smarter than the normal XT BIOS.
Anyway, my knowlegde about XT machines is a bit sketchy. 😅
I believe I did read that the IBM 5150 determined the total amount of random access memory
via DIP switch settings, while the IBM 5160 was a bit smarter already and counted the actual memory.
So could it work, by any chance, if I select the IBM 5160 model in PCEm ?
I mean, hardware-wise, 640KiB never was the true limit of any PC model,
since even then it was possible to exchange 64K chips with 256K chips.
The main thing was, as far as I know, that the additional memory was contiguous.
(Btw, sometime ago, I read something about an ancient mod for these old IBMs.
Back in time, people did exchange/modify some of the address decoders (U4?).
Another trick was to use the sockets meant to be used for the ROM BASIC for additional RAM.
I believe the old terminology of that extra memory was High Memory, not to be confused with the HMA.)
Edit: Found again one of these articles I was reading. ^^
"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel
//My video channel//