ZiLOG Z80 User Manual page 56

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0000 222600
0003 cb84
0005 41
0006 05
0007 dd2a2600
000b dd7e00
000e 57
goof dd5e01
0012 93
0013 3008
0015 dd7300
0018 dd7201
001b cbc4
0010 dd23
001f 10ea
0021 cb44
0023 20de
0025 c9
80
15 ; c
16 ; d
17 ; e
18 ; h
19 ; l
20 ; ix
21 ; iy
22 ;
23 sort: ld
24 loop: res
25 ld
26 dec
27 ld
28 next: ld
29 ld
30 ld
31 sub
32 jr
33 ld
34 ld
35 set
36 noex: inc
37 djnz
38
39 bit
40 jr
41 ret
42 ;
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length of data array
first element in comparison
second element in comparison
flag to indicate exchange
unused
pointer into data array
unused
(data), hl ; save data address
flag, h ; initialize exchange flag
b, c ; initialize length counter
b ; adjust for testing
ix, (data) ; initialize array pointer
a, (ix) ; first element in comparison
d, a ; temporary storage for element
e, (ix+1) ; second element in comparison
e ; comparison first to second
pc, noex-$ ; if first > second, no jump
(ix), e ; exchange array elements
(ix+i), d
flag, h ; record exchange occurred
ix ; point to next data element
next-$ ; count number of comparisons
; repeat if more data pairs
flag, h ; determine if exchange occurred
nz, loop-$ ; continue if data unsorted
; otherwise, exit