murphy@pur-phy (William J. Murphy) (07/29/89)
I am woking on a program to interface with a DataTranslation board
from my Zenith PC 386. I came across a type of variable which I know
nothing about. The program was written in Turbo C and TC uses a type
interrupt. I looked at the manual for TC and found that this is specific
to TC, so my question is how would I implement this in MicroSoft C 5.1?
I have little experience programming interrupts, in fact this is
my first time in MS-DOS.
/* Function Prototypes */
void interrupt DTintHandler(unsigned bp, unsigned di, unsigned si,
unsigned ds, unsigned es, unsigned dx,
unsigned cx, unsigned bx, unsigned ax);
void InitInt( int vector, void interrupt (*haddr) ());
void interrupt DTintHandler(unsigned bp, unsigned di, unsigned si,
unsigned ds, unsigned es, unsigned dx,
unsigned cx, unsigned bx, unsigned ax);
{
if (( inport(ADSCR) & BIT15) == BIT15)
aderror = TRUE;
if(( inport(SUPSCR) & BIT15) == BIT15)
{
done = TRUE;
outport(SUPSCR, BIT13);
}
outport(MASTER, EOI);
outport(SLAVE, EOI);
}
void InitInt( int vector, void interrupt (*haddr) ());
{
unsigned regvalue;
setvect(vector, haddr);
disable();
regvalue = inport(MSTRMASKREG);
outport(MSTRMASKREG, regvalue & 0xFB);
regvalue = inport(SLVMASKREG);
outport(SLVMASKREG, regvalue & !IRQ15);
enable();
}
Well, there are the two functions, I believe the inport and outport
would be equivalent to MSC's inpw, and outpw. setvect must be taking the
address which is passed and shoving it into the appropriate interrupt
register. inthis case what gets passed is the following
InitInt(VECTNUM, DTintHandler)
where VECTNUM = 0x77. Lastly I assume that enable() and disable() perform
on the enabling/disabling of interrupts.
Since I don't own Turbo C, I would rather get this translated to MSC.
Does anyone have experience with this?
Please e-mail any ideas (can you really e-mail and idea) or thoughts
on this subject. I am not a regular reader of comp.lang.c or comp.sys.ibm.pc.
Thanks,
Bill Murphy
murphy@newton.physics.purdue.edublanier@mips.COM (Brian Lanier) (07/29/89)
In article <2388@pur-phy> murphy@pur-phy (William J. Murphy) writes: >I came across a type of variable which I know >nothing about. The program was written in Turbo C and TC uses a type >interrupt. I looked at the manual for TC and found that this is specific >to TC, so my question is how would I implement this in MicroSoft C 5.1? From what I have read, the way to accomplish this in MSC is to use the -S switch to generate the source listing and change "ret" to "iret". Of course, you then have to assemble/link that code in with the C. Alternately, you could use debug, find the address of the ret instruction and change it that way. (This is a real pain in the tuckus) (see note) To install the interrupt, use Function 35h to get the current vector (for later chaining, of course) and use Function 25h to set the new vector. This takes the place of Turbo C's getvect() and setvect(). (I thinks MSC 5.0 added dos_getvect and dos_setvect, but I'm not sure). I hope that's what you were asking for. Brian Lanier blanier@mips.com blanier@scueng.scu.edu note: if you feel you have to use the debug method (maybe you don't have a good assembler), the coding for ret is : 11000011 return within a segment 11000000 data-low data-high return within a segment with a pop value 11001011 intersegment return 11001010 data-low data-high intersegment return with a pop value I would be suprised if there was a pop value (if there is you have to code it out as iret won't let you have one.) The coding for iret is : 11001111 Just replace the right bit pattern. Use the u in debug to find the ret.
abcscnuk@csuna.csun.edu (Naoto Kimura) (07/30/89)
The "interrupt" keyword is should be available with MSC 5.1, as this
was available on MSC 5.0 (but was never mentioned anywhere in the
manual except for the phrase "make sure that you declare the function
as an interrupt" -- for each of the functions that manipulated the
system interrupt table). Another thing to watch out is to make sure
that you declare all functions that are declared as "interrupt" that
you make also make it "far" or you may have problems in linking (this
one was another thing that made me scratch my head for nearly 3 days).
If you are using hardware interrupts, you probably want the header to
look something like:
void far interrupt intserver() /* note lack of args */
I don't recall if the compiler generated the code to push all the
registers or not. You might want to use the appropriate flags to
generate assembly language output and check to make sure that it does.
If it doesn't then you should use some inline assembly (I don't recall
if MSC had it or not) or write the interrupt service routine in
assembly.
//-n-\\ Naoto Kimura
_____---=======---_____ (abcscnuk@csuna.csun.edu)
====____\ /.. ..\ /____====
// ---\__O__/--- \\ Enterprise... Surrender or we'll
\_\ /_/ send back your *&^$% tribbles !!t-davidw@microsoft.UUCP (David Weigant) (07/31/89)
In article <24259@abbott.mips.COM> blanier@mips.COM (Brian Lanier) writes: >In article <2388@pur-phy> murphy@pur-phy (William J. Murphy) writes: >>I looked at the manual for TC and found that this is specific >>to TC, so my question is how would I implement this in MicroSoft C 5.1? > >From what I have read, the way to accomplish this in MSC is to use the >-S switch to generate the source listing and change "ret" to "iret". Of >course, you then have to assemble/link that code in with the C. The interrupt keyword is supported by both MSC and QC, so it is not necessary to hack the generated source listing or modify the .exe with debug. You can find information on using the interrupt keyword in the readme.doc that comes with MSC 5.x or you can query on 'interrupt' inside QC 2.00. For getting and setting interrupt vectors, the functions _dos_getvect and _dos_setvect can be used. They map to DOS functions 0x35 and 0x25 respectively. Hope this helps David Weigant
cb@cci632.UUCP (Just another hired gun (n2hkd)) (08/01/89)
SInce I don't like to reinvent the wheel, I cheat or buy :-)... This problem is also analgous (gawd awful spelling :-( ), to the TSR problem. Hence buying one of those TSR libraries seems like a neat way to go... try "resident_C" by essential or some such program. They even tell what needs to be protected when you're trying to something real with dos, actually they handle that stuff really well (like the ^break int etc...) Hope this helps.... -- I volunteered for the rights in America, and now I'm losing them, AAARGHH email: cb@cci632 or !rochester!kodak!n2hkd!curtis Fight for your RIGHTS! Curtis Braun, N2HKD, Computronics, PO Box 1002 Fairport NY, 14450