Hai,

Does anybody know what's the top most free address to use? I know sysvars start somewhere at #F300.
Is there some BASIC mem I should know about? StackPointer?

Is such info available somewhere?

I coulnd't find anything I did not know already.

The contents of HIMEM (FC4AH) is the higher free address disposable. You can find more detailed info on chapter 3.2 (Detailed View of the User's Area) of the MSX THB

I know, but the value of HIMEM just points to highest free address, which can be altered by software. For example, DOSII sets this adress somewhere on E510H. (dos stores error messages there).

But I'm interested in high adr for MSX foundation to be working. (slot, page info, peripheral info etc etc)

in other words: WHAT goes where, exactly in the memory area before sysvars

edit: The TH says: user data from 8000 to #f380 (as I expected)

So what you mean is: what is between the address pointed by HIMEM and 0F380H ?

This totally depends on the expansions you are using.
As you allready pointed out, the MSX disk kernel allocates a chunk off memory, but this consists of a static part ( 0F1C9H-0F37FH) and a variable part. The variable part depends on the type of disks, the number of diskdrives and the diskdriver itself. So there is no fixed lowest address.
Futhermore other expansions can allocate workspace, for example the FM-PAC (after a CALL MUSIC).

But from a programmers point of view, only HIMEM is important, because that is your upper limit.

If you are interested in the space allocated by a diskrom then this link might be useful (although it is in Dutch).

www.msxarchive.nl/pub/msx/mirrors/msx2.com/sources/diskvar2.txt

Also, the next link might be useful. It contains the sources of many msx roms. Some of them are quite well documented.

sourceforge.net/projects/msxsyssrc/