"Footprint" of DOS.SYS?

[+Larry]

Is there an easy way to find the "footprint" (memory usage) of various DOS.SYS modules?

 

I know that virtually all of them load at $700, but finding their end is causing me trouble.

 

Thanks,

Larry

[Rybags]

MEMLO (dec. 743, 744) contains the lowest free RAM address pointer.

 

So, once DOS loads, either use a monitor to view those locations - or you can just ?PEEK from BASIC.

 

The end point of the load won't necessarily be the start of free RAM since DOS needs extra memory for workspace, buffers etc.

[+Larry]

Thanks, Rybags!

 

That is most helpful.

 

MEMLO (dec. 743, 744) contains the lowest free RAM address pointer.

 

So, once DOS loads, either use a monitor to view those locations - or you can just ?PEEK from BASIC.

 

The end point of the load won't necessarily be the start of free RAM since DOS needs extra memory for workspace, buffers etc.

[walter_J64bit]

MEMLO (dec. 743, 744) contains the lowest free RAM address pointer.

 

So, once DOS loads, either use a monitor to view those locations - or you can just ?PEEK from BASIC.

 

The end point of the load won't necessarily be the start of free RAM since DOS needs extra memory for workspace, buffers etc.

Is this Atari DOS 2.5?

[Rybags]

Any DOS.

 

BASIC, or whatever language/app is used will use MEMLO as it's starting point to store programs/data.

[+Larry]

Any DOS.

 

BASIC, or whatever language/app is used will use MEMLO as it's starting point to store programs/data.

 

Here are some MEMLO values for several Dos versions I have looked at thus far:

 

Dos 2.0s $1CFC

Dos 2.5 $1E1C

MyDos 4.50 $1EE9

MyDos 3.07 $1BE9

OSS Dos from Basic XL toolkit $1B00 (this Dos can't load a DUP.SYS)

Sparta Dos 3.2G $17A2

Sparta Dos X 4.22 $10FF (!!!)

 

-Larry

[drac030]

Sparta Dos X 4.22 $10FF (!!!)

 

Oh, this is quite high for this DOS. When properly configured, it can go below $0F00

 

PS. I can add something to your list:

 

DOS 1.0 $2A80

 

Now, that's a "!!!"

Edited November 13, 2007 by drac030

[walter_J64bit]

Hmmm, I see is there any way to show how much RAM is freed up by using the MEMLO?

[Heaven/TQA]

Walter...? in Basic print free(0)?

[Rybags]

DOS 1.0 always loaded DUP as well (from memory - I don't think I ever had the "pleasure")

 

FRE(0) is just APPMHI - MEMLO

 

APPMHI (14,15 dec) tells the OS the highest location that the application is using (ie BASIC or whatever language should set it as the program/variable storage grows)

 

A neat trick on OSA and OSB (400/800) was to set APPMHI to something like $9D00 - the OS then would not be able to open a screen after System Reset, so it in a way was a means to protect software from funny business.

 

The bug was fixed in the XL OS.

[walter_J64bit]

Walter...? in Basic print free(0)?

All I get is an error 9

[miker]

Not ?FREE(0) but ?FRE(0), tebe has something misspelled.