Back to home page

DOS ain't dead

Forum index page

Log in | Register

Back to the forum
Board view  Mix view

Conflict between JEMMEX and BIOS service E820h (Developers)

posted by Japheth Homepage, Germany (South), 08.01.2021, 04:57

> First of all - I have found a bug in Japheth's utility GETI15EX. It does
> not correctly process the E820h chain and omits the last record.
> (log here )

Yes. This tool is totally outdated. The up-to-date tool is called MEMSTAT and contained in the jemmex package.

> But if I load JemmEX (from config.sys) the memory map is corrupted and the
> last entry from E820h is corrupted and is marked as memory region type 2
> (aka reserved).

That's quite correct. It's not "corrupted", however. The currect jemmex implements XMS v3.5, that is, the XMM handles memory beyond 4 GB - and it wants to handle that memory exclusively. For this reason it intercepts int 15h, ax=e820 and marks the corresponding regions as "reserved". It's documented, so all you need is to read XMS35.txt.

If you don't want this, there's another jemm version, jemmexl.exe, that leaves int 15h e820h untouched.

---
MS-DOS forever!

 

Complete thread:

Back to the forum
Board view  Mix view
22049 Postings in 2034 Threads, 396 registered users, 220 users online (0 registered, 220 guests)
DOS ain't dead | Admin contact
RSS Feed
powered by my little forum