🚀 go-pugleaf

mvdl@et.tudelft.nl writes:
: 
: How (with what interrupt or so) can I detect whetther or not ANY fossil-driver
: is installed ?
: 
: I've read about BNU detection in Brown & Kyle's 'PC INTERRUPTS', but will
: this interrupt also work for X00 ?
: 
: Step 2 is how to detect whether or not the loaded fossil-driver is X00 (it
: must be installed because of the extended interrupts I use from X00), but
: therefore I could use the 'return information about FOSSIL' interrupt that 
: is available in any Fossil.
: 
: Step 1 is the most important at this moment..

In order to detect the presence of the fossil driver i usually check
for the word at offset 6 from the beginning of the int14h interrupt
handler code. If there is a fossil driver loaded it should contain
1954h. The appropriate piece of code may look something like this:

 ; get the current int14h handler entry point address
   
   mov  ax, 3514h
   int  21h		; ES:BX points to int14h handler code

 ; check for the fossil magic word in there

   cmp es:[bx+6], 1954h
   jne  noFossil
   
 ; standard 'return fossil info' stuff follows...

The only possible drawback is that if some dirty TSR or tricky multitasker
intercept int14 after fossil got installed. All the fossil extenders 
i've seen which work on top of the standard fossils follow the same 
rule -- 1954h at offset 6 from the beginning of the handler code. They
have to since most bbs software checks for it... As for multitaskers --
both BNU and X00 have 're-capture' feature, which ensures that the
fossil code gets control first.

Hope this helps,
> Pete

-- 

Pete Kvitek <kvitekp@jvd.msk.su>, FidoNet(tm) 2:5020/6 | Phone:+7-095-328-1327
Speaking from but not for JV Dialogue, Moscow, Russia  | Fax:  +7-095-329-4711