BIOS Function Reference

Bconin()

WORD dev;

	Bconin() retrieves a character (if one is waiting) from the specified device.

Opcode	2 (0x02)

Availability	All TOS versions.

Parameters	dev specifies the device to read from as follows:

	Name		dev	Device
	DEV_PRINTER		0	Parallel port
	DEV_AUX		1	Auxillary device (normally the RS-232 port, however, TOS versions with Bconmap() can map in other devices to this handle)
	DEV_CONSOLE		2	Console device (keyboard)
	DEV_MIDI		3	MIDI Port
	DEV_IKBD		4	IKBD Controller (not available as an input device)
	DEV_RAW		5	Console device (keyboard)
	See Overview		6 -	Additional devices (as available)

Binding	move.w dev,-(sp) move.w #$02,-(sp) trap #13 addq.l #4,sp

Return Value	Bconin() returns a bit array arranged as follows:

	Bits 31-24	Bits 23-16			Bits 15-8	Bits 7-0
	Shift key status (see Kbshift() )	Keyboard Scan Code			Reserved (0)	ASCII value

Comments	The shift key status is only returned if the system variable conterm (char *(0x484) ) has bit 3 set. This is normally disabled.Non-ASCII keys return 0 in bits 7-0.

See Also	Bconstat(), Cconin(), Cauxin()

Bconout()

LONG Bconout( dev, ch )

WORD dev, ch;

	Bconout() outputs a character to a named device.

Opcode	3 (0x03)

Availability	All TOS versions.

Parameters	dev specifies the output device as follows:

	Name	dev	Device
	DEV_PRINTER	0	Parallel port
	DEV_AUX	1	Auxillary device (see note under Bconin() )
	DEV_CONSOLE	2	Console device (screen)
	DEV_MIDI	3	MIDI port
	DEV_IKBD	4	Keyboard (IKBD)
	DEV_RAW	5	Raw screen device (control characters and escapes are not processed)
	See Overview	6 -	Additional devices (as available)

Binding	move.w ch,-(sp) move.w dev,-(sp) move.w #$03,-(sp) trap #13 addq.l #6,sp

Return Value	Bconout() returns 0 if the character was sent successfully or non-zero otherwise.

See Also	Bconin(), Cconout(), Cauxout(), Cprnout(), Bcostat()

Bconstat()

LONG Bconstat( dev )

WORD dev;

	Bconstat() determines whether the specified device is prepared to transmit at least one character.

Opcode	1 (0x01)

Availability	All TOS versions.

Parameters	dev specifies the device to check as listed under Bconin().

Binding	move.w dev,-(sp) move.w #$01,-(sp) trap #13 addq.l #4,sp

Return Value	Bconstat() returns 0 if no characters are waiting or -1 if characters are waiting to be received.

See Also	Bconin(), Cconis(), Cauxis()

Bcostat()

LONG Bcostat( dev )

WORD dev;

	Bcostat() determines if the specified device is prepared to receive a character.

Opcode	8 (0x08)

Availability	All TOS versions.

Parameters	dev specifies the device to poll as listed under Bconout().

Binding	move.w dev,-(sp) move.w #$08,-(sp) trap #13 addq.l #4,sp

Return Value	Bcostat() returns 0 if the device is not ready to receive characters or -1 otherwise.

Caveats	A bug in TOS 1.0 existed that caused the IKBD and MIDI device numbers to become swapped when being handled by the Bcostat() call, subsequently returning data for the wrong device. To allow previously written programs to continue operating correctly, this bug has been maintained on purpose in all current versions of TOS. You should therefore specify a value of 3 for the IKBD and 4 for MIDI for this call only.

See Also	Bconout(), Cauxos(), Cconos(), Cprnos()

Drvmap()

ULONG Drvmap( VOID )

	Drvmap() returns a list of mounted drives.

Opcode	10 (0x0A)

Availability	All TOS versions.

Parameters	None.

Binding	move.w #$0A,-(sp) trap #13 addq.l #2,sp

Return Value	Drvmap() returns a ULONG bitmap of mounted drives. For each drive present, its bit is enabled. Drive 'A:' is bit 0, drive 'B:' is bit 1, and so on.

Comments	Single floppy systems will indicate that two drives are available since both drives can actually be addressed. A request for drive 'B:' will simply cause TOS to ask the user to insert 'Disk B' and provide automatic handling routines for all disk swapping.

See Also	Dsetdrv()

Getbpb()

BPB *Getbpb( dev )

WORD dev;

	Getbpb() returns the address of the current BPB (Bios Parameter Block) for a mounted device.

Opcode	7 (0x07)

Availability	All TOS versions.

Parameters	dev specifies the mounted device ('A:' = 0, 'B:' = 1) .

Binding	move.w dev,-(sp) move.w #$07,-(sp) trap #13 addq.l #4,sp

Return Value	Getbpb() returns a pointer to the device's BPB. The BPB is defined as follows: typedef struct { WORD recsiz; /* bytes per sector / WORD clsiz; / sectors per cluster / WORD clsizb; / bytes per cluster / WORD rdlen; / sector length of root directory / WORD fsiz; / sectors per FAT / WORD fatrec; / starting sector of second FAT / WORD datrec; / starting sector of data / WORD numcl; / clusters per disk / WORD bflags; / bit 0=1 - 16 bit FAT, else 12 bit */ } BPB;

Caveats	A media change must be forced after calling this function prior to making any GEMDOS calls. Failure to do so may cause GEMDOS to become unaware of a disk change causing data loss. Refer to the discussion of forcing a media change earlier in this chapter.

Getmpb()

VOID Getmpb( mpb )

	Getmpb() returns information regarding GEMDOS free and allocated memory blocks.

Opcode	0 (0x00)

Availability	All TOS versions.

Parameters	mpb is a pointer to a MPB structure which is filled in by the function. The related structures are defined as follows: typedef struct md { struct md m_link; / pointer to next block / VOIDP m_start; / pointer to start of block / LONG m_length; / length of block / BASEPAGE m_own; /* pointer to basepage of owner / } MD; typedef struct mpb { MD mp_mfl; /* free list / MD mp_mal; /* allocated list / MD mp_rover; /* roving pointer */ } MPB;

Binding	pea mpb clr.w -(sp) trap #13 addq.l #6,sp

Caveats	MultiTOS uses a very different method of memory management which makes this call useless.

Comments	An application should never attempt to modify any of the returned information nor make any assumptions about memory allocation because of this function.

See Also	Malloc(), Mfree()

Kbshift()

LONG Kbshift( mode )

WORD mode;

	Kbshift() allows the user to interrogate or modify the state of the keyboard 'special' keys.

Opcode	11 (0x0B)

Availability	All TOS versions.

Parameters	mode is -1 to read the state of the keys or a mask of the following values to change the current state:

		Name	Mask	Meaning
		K_RSHIFT	0x01	Right shift key depressed
		K_LSHIFT	0x02	Left shift key depressed
		K_CTRL	0x04	Control key depressed
		K_ALT	0x08	Alternate key depressed
		K_CAPSLOCK	0x10	Caps-lock engaged
		K_CLRHOME	0x20	Clr/Home key depressed
		K_INSERT	0x40	Insert key depressed

Binding	move.w mode,-(sp) move.w #$0B,-(sp) trap #13 addq.l #4,sp

Return Value	Kbshift() returns the state that the keyboard 'special' keys were in prior to the call.

Comments	Kbshift() is not a particularly fast call. If you are only interested in reading the state a documented macro follows that replaces Kbshift() and is much faster. Call the kb_init() function, as shown below, before using: char p_kbshift; #define Kbstate() p_kbshift VOID kb_init(VOID) { /* GetROMSysbase is defined in the BIOS Overview / OSHEADER osheader = GetROMSysbase(); if ( osheader->os_version == 0x0100 ) p_kbshift = (char )0xe1bL; else p_kbshift = (char **)osheader->p_kbshift; }

See Also	evnt_keybd(), evnt_multi(), Cconin(), Bconin()

Mediach()

LONG Mediach( dev )

WORD dev;

	Mediach() inquires as to whether the 'media' has been changed since the last disk operation on a removable block device (floppy, removable hard drive, floptical, etc...).

Opcode	9 (0x09)

Availability	All TOS versions.

Parameters	dev specifies the mounted device number to inquire ('A:' = 0, 'B:' = 1, etc.).

Binding	move.w dev,-(sp) move.w #$09,-(sp) trap #13 addq.l #4,sp

Return Value	Mediach() returns one of three values:

		Name	Value	Meaning
		MED_NOCHANGE	0	Media has not changed
		MED_UNKNOWN	1	Media may have changed
		MED_CHANGED	2	Media has changed

See Also	Getbpb()

Rwabs()

LONG Rwabs( mode, buf, count, recno, dev, lrecno )

WORD mode;

VOIDP buf;

WORD count,recno,dev;

LONG lrecno;

	Rwabs() reads and writes sectors to a mounted device.

Opcode	4 (0x04)

Availability	All TOS versions. Hard disk access requires the use of a hard disk driver (such as AHDI). The long sector offset version is only available as of AHDI 3.0. AHDI version numbers can be inquired through system variable pun_ptr (see discussion earlier in this chapter).

Parameters	mode is a bit mask which effects the operation to be performed as follows:

	Name	Bit	Meaning
	RW_READ or RW_WRITE	0	0 = Read, 1 = Write
	RW_NOMEDIACH	1	Do not read or modify the media change status.
	RW_NORETRIES	2	Disable retries
	RW_NOTRANSLATE	3	Do not translate logical sectors into physical sectors (recno specifies physical instead of logical sectors)

	The read or write operation is performed at address buf. buf must be count * bytes per logical sector in logical mode or count * 512 bytes in physical mode. count specifies how many sectors will be transferred. dev specifies the index of the mounted device. In logical mode, 'C:' is 2, 'D:' is 3, etc... In physical mode, devices 2-9 are the ACSI devices and 10-17 are SCSI devices.recno specifies the first sector to read from. If you need to specify a long offset, set recno to -1 and pass the long value in lrecno. When using a version of the AHDI below 3.0, the parameter lrecno should not be passed.

Binding	/* If running AHDI <3.0 omit first parameter */ move.l lrecno,-(sp) move.w dev,-(sp) move.w recno,-(sp) move.w count,-(sp) pea buf,-(sp) move.w mode,-(sp) move.w #$04,-(sp) trap #13 lea 18(sp),sp

Return Value	Rwabs() returns E_OK (0) if successful or a negative BIOS error code otherwise.

Comments	Some C compilers (Lattice C in particular) have a secondary binding called Lrwabs() used to pass the additional parameter.This function may invoke the critical error handler (etv_critic).

Setexc()

(VOIDP)() Setexc( num, newvec )

WORD num;

VOID (*newvec)();

	Setexc() reads or modifies system exception vectors.

Opcode	5 (0x05)

Availability	All TOS versions.

Parameters	num indicates the vector number you are interested in. To obtain the vector number divide the address of the vector by 4. Some common vectors are:

	Name	num	Vector
	VEC_BUSERROR VEC_ADDRESSERROR VEC_ILLEGALINSTRUCTION	0x02 - 0x04	Bomb errors (Bus, Address, Instruction)
	VEC_GEMDOS	0x21	Trap #1 (GEMDOS)
	VEC_GEM	0x22	Trap #2 (AES/VDI)
	VEC_BIOS	0x2D	Trap #13 (BIOS)
	VEC_XBIOS	0x2E	Trap #14 (XBIOS)
	VEC_TIMER	0x100	System timer (etv_timer)
	VEC_CRITICALERROR	0x101	Critical error handler (etv_critic)
	VEC_TERMINATE	0x102	Process terminate handle (etv_term)

	newvec should be the address of your new vector handler. Passing a value of VEC_INQUIRE ((VOIDP)-1) will not modify the vector.

Binding	pea newvec move.w num,-(sp) move.w #$05,-(sp) trap #13 addq.l #8,sp

Return Value	The original value of the vector is returned by the call.

Comments	You must reinstate old vector handlers you changed prior to your process exiting.Programs which modify replace system vector code should install themselves following the conventions of the XBRA protocol. For details, consult the overview portion of this chapter.

Tickcal()

LONG Tickcal( VOID )

	Tickcal() returns the system timer calibration.

Opcode	6 (0x06)

Availability	All TOS versions.

Parameters	None.

Binding	move.w #$06,-(sp) trap #13 addq.l #2,sp

Return Value	Tickcal() returns a LONG indicating the number of milliseconds between system clock ticks.

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