Home » Archimedes archive » Acorn User » AU 1997-01 B.adf » Regulars » StarInfo/Stoner/Snow
StarInfo/Stoner/Snow
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » Archimedes archive » Acorn User » AU 1997-01 B.adf » Regulars |
| Filename: | StarInfo/Stoner/Snow |
| Read OK: | ✔ |
| File size: | 0612 bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
1REM Snow
2REM Nigel Stoner 1995
3ON ERROR REPORT:PRINT" at line ";ERL:END
4PROCinit
5CALLcode
6END
7DEF PROCinit
8MODE 13:OFF:GCOL 0,63:flakes%=1999
9DIM code 256, snow% (flakes%+10)*16, rand% 4096*4
10PROCassem
11p%=0:FOR a%=0 TO 4096:rand%!p%=RND(10)-5:p%+=4:NEXT a%
12p%=0
13FOR a%=0 TO flakes%:snow%!p%=RND(1280):snow%!(p%+4)=RND(1024):snow%!(p%+8)=RND(1024):snow%!(p%+12)=base%+320:p%+=16:NEXT a%
14ENDPROC
15DEF PROCassem
16FOR pass = 0 TO 3 STEP 2
17P%=code
18[OPT pass
19STMFD R13!,{R14}
20LDR R8,rand:MOV R7,#0:ADR R6,colors
21.main_loop
22LDR R10,flakes:LDR R9,snow
23.flake_loop
24LDMIA R9,{R1-R4}:MOV R0,#0:STRB R0,[R4]:STRB R0,[R4,#1]
25BL random
26AND R0,R0,#5:SUB R0,R0,#3:MUL R0,R3,R0
27MOV R0,R0,ASR#8:ADD R1,R1,R0:MOV R0,R3,ASR#4
28MOV R0,R0,ASR#3:ADD R0,R0,#1:ADD R2,R2,R0
29CMP R1,#0:MOVLE R1,#1280:SUBLE R1,R1,#4
30CMP R1,#1280:MOVGE R1,#0:CMP R2,#1020
31MOVGE R2,#0:STMIA R9!,{R1-R3}
32.plot_snowdrop
33MOV R1,R1,ASR#2:MOV R2,R2,ASR#2:LDR R4,base%
34ADD R4,R4,R2,ASL #6:ADD R4,R4,R2,ASL #8:ADD R4,R4,R1
35MOV R3,R3,ASR#6:LDR R0,[R6,R3]:STRB R0,[R4]
36STRB R0,[R4,#1]:STMIA R9!,{R4}:SUBS R10,R10,#1
37CMP R10,#0:BNE flake_loop
38MOV R0,#19:SWI "OS_Byte":MOV R0,#129
39SWI "OS_ReadEscapeState":BCC main_loop
40LDMFD R13!,{PC}
41.random
42STMFD R13!,{R14}:LDR R0,[R8,R7]:ADD R7,R7,#1:CMP R7,#4096:MOVGE R7,#0
43LDMFD R13!,{PC}
44.flakes EQUD flakes%
45.rand EQUD rand%
46.snow EQUD snow%
47.base% EQUD 148:EQUD -1
48.colors
49EQUD &2F2E2D2C:EQUD &D3D2D1D0:EQUD &FCFDFEFF:EQUD &FFFFFFFF:EQUD &FCFDFFFF
50]
51NEXT pass
52SYS "OS_ReadVduVariables",base%,base%
53ENDPROC
� Snow
� Nigel Stoner 1995
� � �:�" at line ";�:�
�init
�code
�
� �init
� 13:�:� 0,63:flakes%=1999
3� code 256, snow% (flakes%+10)*16, rand% 4096*4
�assem
2p%=0:� a%=0 � 4096:rand%!p%=�(10)-5:p%+=4:� a%
p%=0
s� a%=0 � flakes%:snow%!p%=�(1280):snow%!(p%+4)=�(1024):snow%!(p%+8)=�(1024):snow%!(p%+12)=base%+320:p%+=16:� a%
�
� �assem
� pass = 0 � 3 � 2
P%=code
[OPT pass
STMFD R13!,{R14}
'LDR R8,rand:MOV R7,#0:ADR R6,colors
.main_loop
LDR R10,flakes:LDR R9,snow
.flake_loop
;LDMIA R9,{R1-R4}:MOV R0,#0:STRB R0,[R4]:STRB R0,[R4,#1]
BL random
(� R0,R0,#5:SUB R0,R0,#3:MUL R0,R3,R0
0MOV R0,R0,ASR#8:ADD R1,R1,R0:MOV R0,R3,ASR#4
-MOV R0,R0,ASR#3:ADD R0,R0,#1:ADD R2,R2,R0
+CMP R1,#0:MOVLE R1,#1280:SUBLE R1,R1,#4
)CMP R1,#1280:MOVGE R1,#0:CMP R2,#1020
!MOVGE R2,#0:STMIA R9!,{R1-R3}
.plot_snowdrop
!0MOV R1,R1,ASR#2:MOV R2,R2,ASR#2:LDR R4,base%
"8ADD R4,R4,R2,ASL #6:ADD R4,R4,R2,ASL #8:ADD R4,R4,R1
#/MOV R3,R3,ASR#6:LDR R0,[R6,R3]:STRB R0,[R4]
$2STRB R0,[R4,#1]:STMIA R9!,{R4}:SUBS R10,R10,#1
% CMP R10,#0:BNE flake_loop
&(MOV R0,#19:SWI "OS_Byte":MOV R0,#129
'*SWI "OS_ReadEscapeState":BCC main_loop
(LDMFD R13!,{PC}
) .random
*ISTMFD R13!,{R14}:LDR R0,[R8,R7]:ADD R7,R7,#1:CMP R7,#4096:MOVGE R7,#0
+LDMFD R13!,{PC}
,.flakes EQUD flakes%
-.rand EQUD rand%
..snow EQUD snow%
/.base% EQUD 148:EQUD -1
0 .colors
1NEQUD &2F2E2D2C:EQUD &D3D2D1D0:EQUD &FCFDFEFF:EQUD &FFFFFFFF:EQUD &FCFDFFFF
2]
3
� pass
4(ș "OS_ReadVduVariables",base%,base%
5�
� 00000000 0d 00 01 0a f4 20 53 6e 6f 77 0d 00 02 17 f4 20 |..... Snow..... |
00000010 4e 69 67 65 6c 20 53 74 6f 6e 65 72 20 31 39 39 |Nigel Stoner 199|
00000020 35 0d 00 03 1a ee 20 85 20 f6 3a f1 22 20 61 74 |5..... . .:." at|
00000030 20 6c 69 6e 65 20 22 3b 9e 3a e0 0d 00 04 09 f2 | line ";.:......|
00000040 69 6e 69 74 0d 00 05 09 d6 63 6f 64 65 0d 00 06 |init.....code...|
00000050 05 e0 0d 00 07 0b dd 20 f2 69 6e 69 74 0d 00 08 |....... .init...|
00000060 1e eb 20 31 33 3a 87 3a e6 20 30 2c 36 33 3a 66 |.. 13:.:. 0,63:f|
00000070 6c 61 6b 65 73 25 3d 31 39 39 39 0d 00 09 33 de |lakes%=1999...3.|
00000080 20 63 6f 64 65 20 32 35 36 2c 20 73 6e 6f 77 25 | code 256, snow%|
00000090 20 28 66 6c 61 6b 65 73 25 2b 31 30 29 2a 31 36 | (flakes%+10)*16|
000000a0 2c 20 72 61 6e 64 25 20 34 30 39 36 2a 34 0d 00 |, rand% 4096*4..|
000000b0 0a 0a f2 61 73 73 65 6d 0d 00 0b 32 70 25 3d 30 |...assem...2p%=0|
000000c0 3a e3 20 61 25 3d 30 20 b8 20 34 30 39 36 3a 72 |:. a%=0 . 4096:r|
000000d0 61 6e 64 25 21 70 25 3d b3 28 31 30 29 2d 35 3a |and%!p%=.(10)-5:|
000000e0 70 25 2b 3d 34 3a ed 20 61 25 0d 00 0c 08 70 25 |p%+=4:. a%....p%|
000000f0 3d 30 0d 00 0d 73 e3 20 61 25 3d 30 20 b8 20 66 |=0...s. a%=0 . f|
00000100 6c 61 6b 65 73 25 3a 73 6e 6f 77 25 21 70 25 3d |lakes%:snow%!p%=|
00000110 b3 28 31 32 38 30 29 3a 73 6e 6f 77 25 21 28 70 |.(1280):snow%!(p|
00000120 25 2b 34 29 3d b3 28 31 30 32 34 29 3a 73 6e 6f |%+4)=.(1024):sno|
00000130 77 25 21 28 70 25 2b 38 29 3d b3 28 31 30 32 34 |w%!(p%+8)=.(1024|
00000140 29 3a 73 6e 6f 77 25 21 28 70 25 2b 31 32 29 3d |):snow%!(p%+12)=|
00000150 62 61 73 65 25 2b 33 32 30 3a 70 25 2b 3d 31 36 |base%+320:p%+=16|
00000160 3a ed 20 61 25 0d 00 0e 05 e1 0d 00 0f 0c dd 20 |:. a%.......... |
00000170 f2 61 73 73 65 6d 0d 00 10 16 e3 20 70 61 73 73 |.assem..... pass|
00000180 20 3d 20 30 20 b8 20 33 20 88 20 32 0d 00 11 0b | = 0 . 3 . 2....|
00000190 50 25 3d 63 6f 64 65 0d 00 12 0d 5b 4f 50 54 20 |P%=code....[OPT |
000001a0 70 61 73 73 0d 00 13 14 53 54 4d 46 44 20 52 31 |pass....STMFD R1|
000001b0 33 21 2c 7b 52 31 34 7d 0d 00 14 27 4c 44 52 20 |3!,{R14}...'LDR |
000001c0 52 38 2c 72 61 6e 64 3a 4d 4f 56 20 52 37 2c 23 |R8,rand:MOV R7,#|
000001d0 30 3a 41 44 52 20 52 36 2c 63 6f 6c 6f 72 73 0d |0:ADR R6,colors.|
000001e0 00 15 0e 2e 6d 61 69 6e 5f 6c 6f 6f 70 0d 00 16 |....main_loop...|
000001f0 1e 4c 44 52 20 52 31 30 2c 66 6c 61 6b 65 73 3a |.LDR R10,flakes:|
00000200 4c 44 52 20 52 39 2c 73 6e 6f 77 0d 00 17 0f 2e |LDR R9,snow.....|
00000210 66 6c 61 6b 65 5f 6c 6f 6f 70 0d 00 18 3b 4c 44 |flake_loop...;LD|
00000220 4d 49 41 20 52 39 2c 7b 52 31 2d 52 34 7d 3a 4d |MIA R9,{R1-R4}:M|
00000230 4f 56 20 52 30 2c 23 30 3a 53 54 52 42 20 52 30 |OV R0,#0:STRB R0|
00000240 2c 5b 52 34 5d 3a 53 54 52 42 20 52 30 2c 5b 52 |,[R4]:STRB R0,[R|
00000250 34 2c 23 31 5d 0d 00 19 0d 42 4c 20 72 61 6e 64 |4,#1]....BL rand|
00000260 6f 6d 0d 00 1a 28 80 20 52 30 2c 52 30 2c 23 35 |om...(. R0,R0,#5|
00000270 3a 53 55 42 20 52 30 2c 52 30 2c 23 33 3a 4d 55 |:SUB R0,R0,#3:MU|
00000280 4c 20 52 30 2c 52 33 2c 52 30 0d 00 1b 30 4d 4f |L R0,R3,R0...0MO|
00000290 56 20 52 30 2c 52 30 2c 41 53 52 23 38 3a 41 44 |V R0,R0,ASR#8:AD|
000002a0 44 20 52 31 2c 52 31 2c 52 30 3a 4d 4f 56 20 52 |D R1,R1,R0:MOV R|
000002b0 30 2c 52 33 2c 41 53 52 23 34 0d 00 1c 2d 4d 4f |0,R3,ASR#4...-MO|
000002c0 56 20 52 30 2c 52 30 2c 41 53 52 23 33 3a 41 44 |V R0,R0,ASR#3:AD|
000002d0 44 20 52 30 2c 52 30 2c 23 31 3a 41 44 44 20 52 |D R0,R0,#1:ADD R|
000002e0 32 2c 52 32 2c 52 30 0d 00 1d 2b 43 4d 50 20 52 |2,R2,R0...+CMP R|
000002f0 31 2c 23 30 3a 4d 4f 56 4c 45 20 52 31 2c 23 31 |1,#0:MOVLE R1,#1|
00000300 32 38 30 3a 53 55 42 4c 45 20 52 31 2c 52 31 2c |280:SUBLE R1,R1,|
00000310 23 34 0d 00 1e 29 43 4d 50 20 52 31 2c 23 31 32 |#4...)CMP R1,#12|
00000320 38 30 3a 4d 4f 56 47 45 20 52 31 2c 23 30 3a 43 |80:MOVGE R1,#0:C|
00000330 4d 50 20 52 32 2c 23 31 30 32 30 0d 00 1f 21 4d |MP R2,#1020...!M|
00000340 4f 56 47 45 20 52 32 2c 23 30 3a 53 54 4d 49 41 |OVGE R2,#0:STMIA|
00000350 20 52 39 21 2c 7b 52 31 2d 52 33 7d 0d 00 20 12 | R9!,{R1-R3}.. .|
00000360 2e 70 6c 6f 74 5f 73 6e 6f 77 64 72 6f 70 0d 00 |.plot_snowdrop..|
00000370 21 30 4d 4f 56 20 52 31 2c 52 31 2c 41 53 52 23 |!0MOV R1,R1,ASR#|
00000380 32 3a 4d 4f 56 20 52 32 2c 52 32 2c 41 53 52 23 |2:MOV R2,R2,ASR#|
00000390 32 3a 4c 44 52 20 52 34 2c 62 61 73 65 25 0d 00 |2:LDR R4,base%..|
000003a0 22 38 41 44 44 20 52 34 2c 52 34 2c 52 32 2c 41 |"8ADD R4,R4,R2,A|
000003b0 53 4c 20 23 36 3a 41 44 44 20 52 34 2c 52 34 2c |SL #6:ADD R4,R4,|
000003c0 52 32 2c 41 53 4c 20 23 38 3a 41 44 44 20 52 34 |R2,ASL #8:ADD R4|
000003d0 2c 52 34 2c 52 31 0d 00 23 2f 4d 4f 56 20 52 33 |,R4,R1..#/MOV R3|
000003e0 2c 52 33 2c 41 53 52 23 36 3a 4c 44 52 20 52 30 |,R3,ASR#6:LDR R0|
000003f0 2c 5b 52 36 2c 52 33 5d 3a 53 54 52 42 20 52 30 |,[R6,R3]:STRB R0|
00000400 2c 5b 52 34 5d 0d 00 24 32 53 54 52 42 20 52 30 |,[R4]..$2STRB R0|
00000410 2c 5b 52 34 2c 23 31 5d 3a 53 54 4d 49 41 20 52 |,[R4,#1]:STMIA R|
00000420 39 21 2c 7b 52 34 7d 3a 53 55 42 53 20 52 31 30 |9!,{R4}:SUBS R10|
00000430 2c 52 31 30 2c 23 31 0d 00 25 1d 43 4d 50 20 52 |,R10,#1..%.CMP R|
00000440 31 30 2c 23 30 3a 42 4e 45 20 66 6c 61 6b 65 5f |10,#0:BNE flake_|
00000450 6c 6f 6f 70 0d 00 26 28 4d 4f 56 20 52 30 2c 23 |loop..&(MOV R0,#|
00000460 31 39 3a 53 57 49 20 22 4f 53 5f 42 79 74 65 22 |19:SWI "OS_Byte"|
00000470 3a 4d 4f 56 20 52 30 2c 23 31 32 39 0d 00 27 2a |:MOV R0,#129..'*|
00000480 53 57 49 20 22 4f 53 5f 52 65 61 64 45 73 63 61 |SWI "OS_ReadEsca|
00000490 70 65 53 74 61 74 65 22 3a 42 43 43 20 6d 61 69 |peState":BCC mai|
000004a0 6e 5f 6c 6f 6f 70 0d 00 28 13 4c 44 4d 46 44 20 |n_loop..(.LDMFD |
000004b0 52 31 33 21 2c 7b 50 43 7d 0d 00 29 0b 2e 72 61 |R13!,{PC}..)..ra|
000004c0 6e 64 6f 6d 0d 00 2a 49 53 54 4d 46 44 20 52 31 |ndom..*ISTMFD R1|
000004d0 33 21 2c 7b 52 31 34 7d 3a 4c 44 52 20 52 30 2c |3!,{R14}:LDR R0,|
000004e0 5b 52 38 2c 52 37 5d 3a 41 44 44 20 52 37 2c 52 |[R8,R7]:ADD R7,R|
000004f0 37 2c 23 31 3a 43 4d 50 20 52 37 2c 23 34 30 39 |7,#1:CMP R7,#409|
00000500 36 3a 4d 4f 56 47 45 20 52 37 2c 23 30 0d 00 2b |6:MOVGE R7,#0..+|
00000510 13 4c 44 4d 46 44 20 52 31 33 21 2c 7b 50 43 7d |.LDMFD R13!,{PC}|
00000520 0d 00 2c 18 2e 66 6c 61 6b 65 73 20 45 51 55 44 |..,..flakes EQUD|
00000530 20 66 6c 61 6b 65 73 25 0d 00 2d 14 2e 72 61 6e | flakes%..-..ran|
00000540 64 20 45 51 55 44 20 72 61 6e 64 25 0d 00 2e 14 |d EQUD rand%....|
00000550 2e 73 6e 6f 77 20 45 51 55 44 20 73 6e 6f 77 25 |.snow EQUD snow%|
00000560 0d 00 2f 1b 2e 62 61 73 65 25 20 45 51 55 44 20 |../..base% EQUD |
00000570 31 34 38 3a 45 51 55 44 20 2d 31 0d 00 30 0b 2e |148:EQUD -1..0..|
00000580 63 6f 6c 6f 72 73 0d 00 31 4e 45 51 55 44 20 26 |colors..1NEQUD &|
00000590 32 46 32 45 32 44 32 43 3a 45 51 55 44 20 26 44 |2F2E2D2C:EQUD &D|
000005a0 33 44 32 44 31 44 30 3a 45 51 55 44 20 26 46 43 |3D2D1D0:EQUD &FC|
000005b0 46 44 46 45 46 46 3a 45 51 55 44 20 26 46 46 46 |FDFEFF:EQUD &FFF|
000005c0 46 46 46 46 46 3a 45 51 55 44 20 26 46 43 46 44 |FFFFF:EQUD &FCFD|
000005d0 46 46 46 46 0d 00 32 05 5d 0d 00 33 0a ed 20 70 |FFFF..2.]..3.. p|
000005e0 61 73 73 0d 00 34 28 c8 99 20 22 4f 53 5f 52 65 |ass..4(.. "OS_Re|
000005f0 61 64 56 64 75 56 61 72 69 61 62 6c 65 73 22 2c |adVduVariables",|
00000600 62 61 73 65 25 2c 62 61 73 65 25 0d 00 35 05 e1 |base%,base%..5..|
00000610 0d ff |..|
00000612 
.