Home » Archimedes archive » Acorn User » AU 1996-02.adf » Regulars » C/c/_swi
C/c/_swi
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 1996-02.adf » Regulars |
| Filename: | C/c/_swi |
| Read OK: | ✔ |
| File size: | 089D bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
/* An example application that uses Acorn's _swi() function */
/* by Steve Mumford for Acorn User - February 1996 */
#include <stdio.h>
#include "swis.h"
/* #Defines */
#define POLL_MASK 1
/* Global variables */
int QUITFLAG = 0;
/* Function prototyping */
int main(void);
void wimpmsg(int, unsigned char[]);
unsigned long int btow(unsigned char[], int);
int
main(void)
{
int task_handle;
unsigned char pollblock[257];
int pollresult;
long int list[1] = {0};
/* The syntax of _swi() is: SWI number, register mask, variables to pass
to registers... More details can be found by reading the swis.h header
file in Acorn's C libraries, but the mask is built up by OR-ing (using
the | operator) various macros together that define which registers
are in use - in the example below, the four bits of data are input
through registers 0 to 3, and the function returns the value passed
back in register 1. */
task_handle =_swi(Wimp_Initialise, _IN(0)|_IN(1)|_IN(2)|_IN(3)|_RETURN(1) , 310, *(int *)"TASK", "_swi() example", list);
do {
pollresult = _swi(Wimp_Poll, _IN(0)|_IN(1)|_RETURN(0), POLL_MASK, pollblock);
switch (pollresult) {
case 17:
case 18:
case 19: wimpmsg(pollresult, pollblock);
break;
}
} while (QUITFLAG == 0);
_swi(Wimp_CloseDown, _IN(0)|_IN(1), task_handle, *(int *)"TASK");
}
void wimpmsg(int result, unsigned char pollblock[])
{
unsigned long int message_action;
/* This function decides which particular message is being passed, and
acts accordingly */
message_action = btow(pollblock, 16);
switch (message_action) {
case 0: QUITFLAG = 1; /* Message_Quit */
break;
}
}
unsigned long int btow(unsigned char pollblock[], int index)
{
/* This routine takes an index to an array of char ints, and converts
the next four bytes into an int */
unsigned long int result = 0;
int loop;
index += 3;
result = pollblock[index--];
for(loop = 0; loop < 3; loop++) {
result = result << 8;
result += pollblock[index--];
}
return (result);
}
00000000 2f 2a 20 41 6e 20 65 78 61 6d 70 6c 65 20 61 70 |/* An example ap|
00000010 70 6c 69 63 61 74 69 6f 6e 20 74 68 61 74 20 75 |plication that u|
00000020 73 65 73 20 41 63 6f 72 6e 27 73 20 5f 73 77 69 |ses Acorn's _swi|
00000030 28 29 20 66 75 6e 63 74 69 6f 6e 20 2a 2f 0a 2f |() function */./|
00000040 2a 20 62 79 20 53 74 65 76 65 20 4d 75 6d 66 6f |* by Steve Mumfo|
00000050 72 64 20 66 6f 72 20 41 63 6f 72 6e 20 55 73 65 |rd for Acorn Use|
00000060 72 20 2d 20 46 65 62 72 75 61 72 79 20 31 39 39 |r - February 199|
00000070 36 20 2a 2f 0a 0a 23 69 6e 63 6c 75 64 65 20 3c |6 */..#include <|
00000080 73 74 64 69 6f 2e 68 3e 0a 23 69 6e 63 6c 75 64 |stdio.h>.#includ|
00000090 65 20 22 73 77 69 73 2e 68 22 0a 0a 2f 2a 20 23 |e "swis.h"../* #|
000000a0 44 65 66 69 6e 65 73 20 2a 2f 0a 0a 23 64 65 66 |Defines */..#def|
000000b0 69 6e 65 20 50 4f 4c 4c 5f 4d 41 53 4b 20 31 0a |ine POLL_MASK 1.|
000000c0 0a 2f 2a 20 47 6c 6f 62 61 6c 20 76 61 72 69 61 |./* Global varia|
000000d0 62 6c 65 73 20 2a 2f 0a 0a 69 6e 74 20 51 55 49 |bles */..int QUI|
000000e0 54 46 4c 41 47 20 3d 20 30 3b 0a 0a 2f 2a 20 46 |TFLAG = 0;../* F|
000000f0 75 6e 63 74 69 6f 6e 20 70 72 6f 74 6f 74 79 70 |unction prototyp|
00000100 69 6e 67 20 2a 2f 0a 0a 69 6e 74 20 6d 61 69 6e |ing */..int main|
00000110 28 76 6f 69 64 29 3b 0a 76 6f 69 64 20 77 69 6d |(void);.void wim|
00000120 70 6d 73 67 28 69 6e 74 2c 20 75 6e 73 69 67 6e |pmsg(int, unsign|
00000130 65 64 20 63 68 61 72 5b 5d 29 3b 0a 75 6e 73 69 |ed char[]);.unsi|
00000140 67 6e 65 64 20 6c 6f 6e 67 20 69 6e 74 20 62 74 |gned long int bt|
00000150 6f 77 28 75 6e 73 69 67 6e 65 64 20 63 68 61 72 |ow(unsigned char|
00000160 5b 5d 2c 20 69 6e 74 29 3b 0a 0a 69 6e 74 0a 6d |[], int);..int.m|
00000170 61 69 6e 28 76 6f 69 64 29 0a 7b 0a 69 6e 74 20 |ain(void).{.int |
00000180 74 61 73 6b 5f 68 61 6e 64 6c 65 3b 0a 75 6e 73 |task_handle;.uns|
00000190 69 67 6e 65 64 20 63 68 61 72 20 20 20 70 6f 6c |igned char pol|
000001a0 6c 62 6c 6f 63 6b 5b 32 35 37 5d 3b 0a 69 6e 74 |lblock[257];.int|
000001b0 20 70 6f 6c 6c 72 65 73 75 6c 74 3b 0a 6c 6f 6e | pollresult;.lon|
000001c0 67 20 69 6e 74 20 20 20 20 6c 69 73 74 5b 31 5d |g int list[1]|
000001d0 20 3d 20 7b 30 7d 3b 0a 0a 20 20 20 20 2f 2a 20 | = {0};.. /* |
000001e0 54 68 65 20 73 79 6e 74 61 78 20 6f 66 20 5f 73 |The syntax of _s|
000001f0 77 69 28 29 20 69 73 3a 20 53 57 49 20 6e 75 6d |wi() is: SWI num|
00000200 62 65 72 2c 20 72 65 67 69 73 74 65 72 20 6d 61 |ber, register ma|
00000210 73 6b 2c 20 76 61 72 69 61 62 6c 65 73 20 74 6f |sk, variables to|
00000220 20 70 61 73 73 0a 20 20 20 20 20 20 20 74 6f 20 | pass. to |
00000230 72 65 67 69 73 74 65 72 73 2e 2e 2e 20 4d 6f 72 |registers... Mor|
00000240 65 20 64 65 74 61 69 6c 73 20 63 61 6e 20 62 65 |e details can be|
00000250 20 66 6f 75 6e 64 20 62 79 20 72 65 61 64 69 6e | found by readin|
00000260 67 20 74 68 65 20 73 77 69 73 2e 68 20 68 65 61 |g the swis.h hea|
00000270 64 65 72 0a 20 20 20 20 20 20 20 66 69 6c 65 20 |der. file |
00000280 69 6e 20 41 63 6f 72 6e 27 73 20 43 20 6c 69 62 |in Acorn's C lib|
00000290 72 61 72 69 65 73 2c 20 62 75 74 20 74 68 65 20 |raries, but the |
000002a0 6d 61 73 6b 20 69 73 20 62 75 69 6c 74 20 75 70 |mask is built up|
000002b0 20 62 79 20 4f 52 2d 69 6e 67 20 28 75 73 69 6e | by OR-ing (usin|
000002c0 67 0a 20 20 20 20 20 20 20 74 68 65 20 7c 20 6f |g. the | o|
000002d0 70 65 72 61 74 6f 72 29 20 76 61 72 69 6f 75 73 |perator) various|
000002e0 20 6d 61 63 72 6f 73 20 74 6f 67 65 74 68 65 72 | macros together|
000002f0 20 74 68 61 74 20 64 65 66 69 6e 65 20 77 68 69 | that define whi|
00000300 63 68 20 72 65 67 69 73 74 65 72 73 0a 20 20 20 |ch registers. |
00000310 20 20 20 20 61 72 65 20 69 6e 20 75 73 65 20 2d | are in use -|
00000320 20 69 6e 20 74 68 65 20 65 78 61 6d 70 6c 65 20 | in the example |
00000330 62 65 6c 6f 77 2c 20 74 68 65 20 66 6f 75 72 20 |below, the four |
00000340 62 69 74 73 20 6f 66 20 64 61 74 61 20 61 72 65 |bits of data are|
00000350 20 69 6e 70 75 74 0a 20 20 20 20 20 20 20 74 68 | input. th|
00000360 72 6f 75 67 68 20 72 65 67 69 73 74 65 72 73 20 |rough registers |
00000370 30 20 74 6f 20 33 2c 20 61 6e 64 20 74 68 65 20 |0 to 3, and the |
00000380 66 75 6e 63 74 69 6f 6e 20 72 65 74 75 72 6e 73 |function returns|
00000390 20 74 68 65 20 76 61 6c 75 65 20 70 61 73 73 65 | the value passe|
000003a0 64 0a 20 20 20 20 20 20 20 62 61 63 6b 20 69 6e |d. back in|
000003b0 20 72 65 67 69 73 74 65 72 20 31 2e 20 2a 2f 0a | register 1. */.|
000003c0 0a 20 20 20 20 74 61 73 6b 5f 68 61 6e 64 6c 65 |. task_handle|
000003d0 20 3d 5f 73 77 69 28 57 69 6d 70 5f 49 6e 69 74 | =_swi(Wimp_Init|
000003e0 69 61 6c 69 73 65 2c 20 5f 49 4e 28 30 29 7c 5f |ialise, _IN(0)|_|
000003f0 49 4e 28 31 29 7c 5f 49 4e 28 32 29 7c 5f 49 4e |IN(1)|_IN(2)|_IN|
00000400 28 33 29 7c 5f 52 45 54 55 52 4e 28 31 29 20 2c |(3)|_RETURN(1) ,|
00000410 20 33 31 30 2c 20 2a 28 69 6e 74 20 2a 29 22 54 | 310, *(int *)"T|
00000420 41 53 4b 22 2c 20 22 5f 73 77 69 28 29 20 65 78 |ASK", "_swi() ex|
00000430 61 6d 70 6c 65 22 2c 20 6c 69 73 74 29 3b 0a 0a |ample", list);..|
00000440 20 20 20 20 64 6f 20 7b 0a 20 20 20 20 20 20 20 | do {. |
00000450 20 70 6f 6c 6c 72 65 73 75 6c 74 20 3d 20 5f 73 | pollresult = _s|
00000460 77 69 28 57 69 6d 70 5f 50 6f 6c 6c 2c 20 5f 49 |wi(Wimp_Poll, _I|
00000470 4e 28 30 29 7c 5f 49 4e 28 31 29 7c 5f 52 45 54 |N(0)|_IN(1)|_RET|
00000480 55 52 4e 28 30 29 2c 20 50 4f 4c 4c 5f 4d 41 53 |URN(0), POLL_MAS|
00000490 4b 2c 20 70 6f 6c 6c 62 6c 6f 63 6b 29 3b 0a 20 |K, pollblock);. |
000004a0 20 20 20 20 20 20 20 73 77 69 74 63 68 20 28 70 | switch (p|
000004b0 6f 6c 6c 72 65 73 75 6c 74 29 20 7b 0a 20 20 20 |ollresult) {. |
000004c0 20 20 20 20 20 20 20 20 20 63 61 73 65 20 31 37 | case 17|
000004d0 3a 0a 20 20 20 20 20 20 20 20 20 20 20 20 63 61 |:. ca|
000004e0 73 65 20 31 38 3a 0a 20 20 20 20 20 20 20 20 20 |se 18:. |
000004f0 20 20 20 63 61 73 65 20 31 39 3a 20 77 69 6d 70 | case 19: wimp|
00000500 6d 73 67 28 70 6f 6c 6c 72 65 73 75 6c 74 2c 20 |msg(pollresult, |
00000510 70 6f 6c 6c 62 6c 6f 63 6b 29 3b 0a 20 20 20 20 |pollblock);. |
00000520 20 20 20 20 20 20 20 20 20 20 20 20 62 72 65 61 | brea|
00000530 6b 3b 0a 20 20 20 20 20 20 20 20 7d 0a 20 20 20 |k;. }. |
00000540 20 7d 20 77 68 69 6c 65 20 28 51 55 49 54 46 4c | } while (QUITFL|
00000550 41 47 20 3d 3d 20 30 29 3b 0a 0a 20 20 20 20 5f |AG == 0);.. _|
00000560 73 77 69 28 57 69 6d 70 5f 43 6c 6f 73 65 44 6f |swi(Wimp_CloseDo|
00000570 77 6e 2c 20 5f 49 4e 28 30 29 7c 5f 49 4e 28 31 |wn, _IN(0)|_IN(1|
00000580 29 2c 20 74 61 73 6b 5f 68 61 6e 64 6c 65 2c 20 |), task_handle, |
00000590 2a 28 69 6e 74 20 2a 29 22 54 41 53 4b 22 29 3b |*(int *)"TASK");|
000005a0 0a 7d 0a 0a 76 6f 69 64 20 77 69 6d 70 6d 73 67 |.}..void wimpmsg|
000005b0 28 69 6e 74 20 72 65 73 75 6c 74 2c 20 75 6e 73 |(int result, uns|
000005c0 69 67 6e 65 64 20 63 68 61 72 20 70 6f 6c 6c 62 |igned char pollb|
000005d0 6c 6f 63 6b 5b 5d 29 0a 7b 0a 20 20 20 20 75 6e |lock[]).{. un|
000005e0 73 69 67 6e 65 64 20 6c 6f 6e 67 20 69 6e 74 20 |signed long int |
000005f0 20 20 6d 65 73 73 61 67 65 5f 61 63 74 69 6f 6e | message_action|
00000600 3b 0a 0a 20 20 20 20 2f 2a 20 54 68 69 73 20 66 |;.. /* This f|
00000610 75 6e 63 74 69 6f 6e 20 64 65 63 69 64 65 73 20 |unction decides |
00000620 77 68 69 63 68 20 70 61 72 74 69 63 75 6c 61 72 |which particular|
00000630 20 6d 65 73 73 61 67 65 20 69 73 20 62 65 69 6e | message is bein|
00000640 67 20 70 61 73 73 65 64 2c 20 61 6e 64 0a 20 20 |g passed, and. |
00000650 20 20 20 20 20 61 63 74 73 20 61 63 63 6f 72 64 | acts accord|
00000660 69 6e 67 6c 79 20 2a 2f 0a 20 20 20 20 6d 65 73 |ingly */. mes|
00000670 73 61 67 65 5f 61 63 74 69 6f 6e 20 3d 20 62 74 |sage_action = bt|
00000680 6f 77 28 70 6f 6c 6c 62 6c 6f 63 6b 2c 20 31 36 |ow(pollblock, 16|
00000690 29 3b 0a 20 20 20 20 73 77 69 74 63 68 20 28 6d |);. switch (m|
000006a0 65 73 73 61 67 65 5f 61 63 74 69 6f 6e 29 20 7b |essage_action) {|
000006b0 0a 20 20 20 20 20 20 20 20 63 61 73 65 20 30 3a |. case 0:|
000006c0 20 51 55 49 54 46 4c 41 47 20 3d 20 31 3b 20 2f | QUITFLAG = 1; /|
000006d0 2a 20 4d 65 73 73 61 67 65 5f 51 75 69 74 20 2a |* Message_Quit *|
000006e0 2f 0a 20 20 20 20 20 20 20 20 20 20 20 20 62 72 |/. br|
000006f0 65 61 6b 3b 0a 20 20 20 20 7d 0a 7d 0a 0a 75 6e |eak;. }.}..un|
00000700 73 69 67 6e 65 64 20 6c 6f 6e 67 20 69 6e 74 20 |signed long int |
00000710 62 74 6f 77 28 75 6e 73 69 67 6e 65 64 20 63 68 |btow(unsigned ch|
00000720 61 72 20 70 6f 6c 6c 62 6c 6f 63 6b 5b 5d 2c 20 |ar pollblock[], |
00000730 69 6e 74 20 69 6e 64 65 78 29 0a 7b 0a 20 20 20 |int index).{. |
00000740 20 2f 2a 20 54 68 69 73 20 72 6f 75 74 69 6e 65 | /* This routine|
00000750 20 74 61 6b 65 73 20 61 6e 20 69 6e 64 65 78 20 | takes an index |
00000760 74 6f 20 61 6e 20 61 72 72 61 79 20 6f 66 20 63 |to an array of c|
00000770 68 61 72 20 69 6e 74 73 2c 20 61 6e 64 20 63 6f |har ints, and co|
00000780 6e 76 65 72 74 73 0a 20 20 20 20 20 20 20 74 68 |nverts. th|
00000790 65 20 6e 65 78 74 20 66 6f 75 72 20 62 79 74 65 |e next four byte|
000007a0 73 20 69 6e 74 6f 20 61 6e 20 69 6e 74 20 2a 2f |s into an int */|
000007b0 0a 20 20 20 20 75 6e 73 69 67 6e 65 64 20 6c 6f |. unsigned lo|
000007c0 6e 67 20 69 6e 74 20 20 20 72 65 73 75 6c 74 20 |ng int result |
000007d0 3d 20 30 3b 0a 20 20 20 20 69 6e 74 20 6c 6f 6f |= 0;. int loo|
000007e0 70 3b 0a 0a 20 20 20 20 69 6e 64 65 78 20 2b 3d |p;.. index +=|
000007f0 20 33 3b 0a 20 20 20 20 72 65 73 75 6c 74 20 3d | 3;. result =|
00000800 20 70 6f 6c 6c 62 6c 6f 63 6b 5b 69 6e 64 65 78 | pollblock[index|
00000810 2d 2d 5d 3b 0a 20 20 20 20 66 6f 72 28 6c 6f 6f |--];. for(loo|
00000820 70 20 3d 20 30 3b 20 6c 6f 6f 70 20 3c 20 33 3b |p = 0; loop < 3;|
00000830 20 6c 6f 6f 70 2b 2b 29 20 7b 0a 20 20 20 20 20 | loop++) {. |
00000840 20 20 20 72 65 73 75 6c 74 20 3d 20 72 65 73 75 | result = resu|
00000850 6c 74 20 3c 3c 20 38 3b 0a 20 20 20 20 20 20 20 |lt << 8;. |
00000860 20 72 65 73 75 6c 74 20 2b 3d 20 70 6f 6c 6c 62 | result += pollb|
00000870 6c 6f 63 6b 5b 69 6e 64 65 78 2d 2d 5d 3b 0a 20 |lock[index--];. |
00000880 20 20 20 7d 0a 0a 20 20 20 20 72 65 74 75 72 6e | }.. return|
00000890 20 28 72 65 73 75 6c 74 29 3b 0a 7d 0a | (result);.}.|
0000089d 
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