/usr/share/z88dk/lib/intwrap82.asm is in z88dk-data 1.8.ds1-10.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 | ; Ti82 interrupt 'wrapper' - by Henk Poley
;-----------------------------------------------------------------------------
; The z88dk makes extensively use of the shadow registers (EXX and EX AF,AF)
; The Ti82 system interrupt doesn't preserve (any of) these regs and
; could thus crash your program. The workaround is to use this interrupt
; all the time, it saves and restores the (shadow-)registers for the
; system interrupt.
; We need the system interrupt when scanning keys (in an easy way), also
; some (other) ROM calls make use of the system interrupt. if the interrupt
; is then not running, the calculator would crash.
;-----------------------------------------------------------------------------
defc intcount = $8501 ; 1 byte - interrupt variable
INCLUDE "#int82.asm" ; Put interrupt loader here
;
xor a ; We need to intialize variables
ld (intcount),a ; by ourself.
;
jr jump_over ; Jump over the interrupt code
;-----------------
; Actual interrupt
;-----------------
.IntProcStart
push af ;
ld a,(intcount) ; Check if own interrupt has quited
bit 7,a ; correctly, then bit 7 is zero
jr nz,int_fix ; If not zero, fix stack...
push hl ;
push de ;
push bc ;
push iy ;
ld iy,_IY_TABLE ;
ld hl,intcount ; If a 'direct interrupt' occures
set 7,(hl) ; right after the TIOS-int, then
; we want bit 7 to be set...
.exit_interrupt ;
exx ; Swap to shadow registers.
ex af,af ; So the TIOS swaps back to the
; normal ones... (the ones we saved
; with push/pops)
rst $38 ;
di ; 'BIG' HOLE HERE... (TIOS does ei...)
di ;
ex af,af ;
exx ;
;
ld hl,intcount ; Interrupt returned correctly, so
res 7,(hl) ; we reset our error-condition...
;
pop iy ;
pop bc ;
pop de ;
pop hl ;
pop af ;
ei ;
ret ;
.int_fix ;
pop af ; Pop AF back
ex af,af ; Fix shadowregs back
exx ;
pop bc ; Pop the returnpoint of RST $38
; from the stack
jr exit_interrupt ; Continue with interrupt
.IntProcEnd
.jump_over
; Memory usage in statvars:
; -------------------------------------------
; $858F / $85FF - 113 bytes - free
; $8600 / $8700 - 256 bytes - IV table
; $8701 / $8786 - 134 bytes - free
; $8787 / $8789 - 3 bytes - JP IntProcStart
; $878A - 1 byte - intcount <--
; $878B / $87A2 - 24 bytes - free
; -------------------------------------------
|