Without more details, this is how I set the H.TIMI routine before moving to IM2:
TIMI equ 0FD9FH RAMAD0 equ 0F341H RAMAD1 equ 0F342H RAMAD2 equ 0F343H RAMAD3 equ 0F344H ; set H.TIMI public isrset@ isrset@: di ; TIMI ld hl, TIMI ld de, oldtim ld bc, 5 ldir ld a, 0F7H ld (TIMI), a ld a, (RAMAD1) ld (TIMI+1), a ld hl, newtim@ ld (TIMI+2), hl ld a, 0c9h ld (TIMI+4), a ei ret ; restore H.TIMI public isrrst@ isrrst@: di ; TIMI ld hl, oldtim ld de, TIMI ld bc, 5 ldir ei ret oldtim: ret ret ret ret ret At newtim, remember to put at the end: ;public newtim@ newtim@: ... jp oldtim
Instead RAMAD1 you could use the one which the code is located, but usually all the segments point to the same RAM slot, not involving DOS2 segment functions (that's another story). By this way it works (tested) even when located at page 0, as the system will call the ISR, and the ISR will use the hook, doing the inter-slot by itself.
Hey Eric,
I think you should try to use DarkSchneider example, I think his idea is best for a C library as it is generic enough to not need any specific addressing on the interrupt function. 
You have to save AF registers at the start of your hooked routine and restore them before exiting. ISR doesn't do it. Then it would be ok
Not needed, the code for Interrupt pushes hl/de/bc/af, exchange registers and AF for their shadow registers, push all those registers again, push ix, iy and then call the HKEY.I hook. 
You can easily check this using either BlueMSX or OpenMSX debuggers on several machines.
Thank you DarkSchneider and Ducasp, I will test that 
You have to save AF registers at the start of your hooked routine and restore them before exiting. ISR doesn't do it. Then it would be ok
Not needed, the code for Interrupt pushes hl/de/bc/af, exchange registers and AF for their shadow registers, push all those registers again, push ix, iy and then call the HKEY.I hook. You can easily check this using either BlueMSX or OpenMSX debuggers on several machines.
You mean the Fusion-C code for interrupt, I suppose. Because ISR doesn't do it
You have to save AF registers at the start of your hooked routine and restore them before exiting. ISR doesn't do it. Then it would be ok
Not needed, the code for Interrupt pushes hl/de/bc/af, exchange registers and AF for their shadow registers, push all those registers again, push ix, iy and then call the HKEY.I hook. You can easily check this using either BlueMSX or OpenMSX debuggers on several machines.
You mean the Fusion-C code for interrupt, I suppose. Because ISR doesn't do it
Either BIOS or DOS when handling RST 38 (interrupt) will save all registers before executing H.KEYI interrupt hook, and will return all those saved registers before returning from that interrupt. Again, if you don't believe, just step through using OpenMSX / BlueMSX on any MSX type available. 
Hi Ducasp
I'm able to include the new interrupt in the library, and compil programs without crash.
But, It seems that the MSX crash when I introduce a Bios Call function. example
static unsigned int count = 0;
/* --------------------------------------------------------- */
void my_interrupt( void ) {
if( IsVsync() == 0 ) return;
count++;
}
/* --------------------------------------------------------- */
int main( void ) {
unsigned int prev_count;
InitInterruptHandler((int)my_interrupt);
prev_count = 0;
while( prev_count < 600 ) {
DisableInterrupt();
prev_count = count;
EnableInterrupt();
Locate(10,1);
printf( "%d\n\r", prev_count );
}
EndInterruptHandler();
return 0;
}
When I use the Locate function the MSX crash.
I also tried to put the Locate in the "DisableInterrupt's block", but it do the same.
There was a silly bug, instead of saving C9 that was in A after the hook RST 30 it was saving HL and thus this was causing some registers to change as result of the content o HL that made it an instruction to change E contents.... 
Fixed that on my google drive, just download the latest version of interrupt.s and it should work fine now.
You have to save AF registers at the start of your hooked routine and restore them before exiting. ISR doesn't do it. Then it would be ok
Not needed, the code for Interrupt pushes hl/de/bc/af, exchange registers and AF for their shadow registers, push all those registers again, push ix, iy and then call the HKEY.I hook. You can easily check this using either BlueMSX or OpenMSX debuggers on several machines.
You mean the Fusion-C code for interrupt, I suppose. Because ISR doesn't do it
Either BIOS or DOS when handling RST 38 (interrupt) will save all registers before executing H.KEYI interrupt hook, and will return all those saved registers before returning from that interrupt. Again, if you don't believe, just step through using OpenMSX / BlueMSX on any MSX type available.
Ok, it was a misunderstanding: just because you referred to DarkSchneider code and there was involved HTIMI and not HKEY, so as you know, during HTIMI you can use EI but you have to preserve register A. I was talking about it
