List of SITS system calls

SITS system calls were done using EMT in older versions, and TRAP in newer. The system call number makes up the lower 7 bits. Bit 200 can be set to have the call fault on error, in which case a $ replaces the . in the symbolic name.

System call inputs are popped off the stack, and outputs are pushed. On error, the Z flag is set and arguments are left on the stack. In the table below, (C) indicates a capability.

Number	Name	Function	Inputs				Outputs
0	.NOOP	-	-				-
1	.FORK	Create new process	Entry point				-
2	.POOFF	Kill this process	-				-
3	.SLEEP	Sleep	Time (least significant)		Time (most significant)		-
4	.SINK	Disable floating point	-				-
5	.FLOAT	Enable floating point	-				-
6	.INVOK	Invoke capability	Function,,capability (C)	argument	argument		(Variable)
7	.QULK	Lock queue	Queue (C)				-
10	.QUNLK	Unlock queue	Queue (C)				-
11	.TTGIV	Give TTY away	Master sphere (C)		Teletype (C)		-
12	.TTGET	Get the TTY	Teletype (C)				-
13	.WRDI	Word input	File (C)				Data
14	.WRDO	Word output	File (C)				-
15	.BYTI	Byte input	File (C)				Data
16	.BYTO	Byte output	File (C)				-
17	.BLKI	Block input File (C)	File (C)	Length	Address		-
20	.BLKO	Block output	File (C)	Length	Address		-
21	.MAP	Create page	Access,,sphere (C)	Destination page,,source type	Source page	Page length,,page offset	-
22	.ALLOC	Allocate swap	Size	Start	Disk		-
23	.CRUSR	Make this a user process	Copy name	Length of name	Pointer to name		-
24	.RDMAP	Read map	Sphere (C)		Address		-
25	.FONT	Read or write font	Function,,font		Address		-
26	.SSTAT	Read system status	Address				-
27	.VIDSW	Set video switch modes	Source		Destination		-
30	.RUG	System sphere breakpoint to RUG	-				-
31	.GERRW	Get error word	-				(Variable)
32	.TIME	Get or set time					-
33	.SYSJB	Perform system job	-				-
34	.GETID	Get process id					-
35	.MFPI	(?)	Address				-
36	.OSPAC	(?)					-