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Conference 7.286::atarist

Title:	Atari ST, TT, & Falcon
Notice:	Please read note 1.0 and its replies before posting!
Moderator:	FUNYET::ANDERSON

Created:	Mon Apr 04 1988
Last Modified:	Tue May 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	1433
Total number of notes:	10312

1224.0. "Disable/enable of keyboard?" by IJSAPL::KDEVRIES (Kees de Vries) Mon Dec 30 1991 02:59

Hi,
I have a requirement to temporary disable ALL keyboard input.
I need this because I am calling a PD subroutine in my programs to play 
some music.
This PD subroutine works only correct as long as nobody hits a key 
during the playback. I don't have the sources of this subroutine.

Writing a 0 to address FFFC00 (Keyboard ACIA Control Register) does
the trick, every input is disabled (including mouse and joystick) and 
the current program continues.

The problem I have is to enable manual input again. 
Restoring the old contents of FFFC00 does NOT work.

Does someboday know the exact layout of the bits in the Keyboard Control
Register?
Or does somebody know a better way of doing this, preferable prgramming
language independent?

Kees de Vries.

T.R	Title	User	Personal Name	Date	Lines
1224.1	USE $484	RIGI::BOLLIGER		`Mon Dec 30 1991 04:32`	20
	( use CONTERM ) the Adress $484 (Hexa) contains some Bits you could use the BITS are: bit 0 = key Klick on/off bit 1 = key repeat on/off bit 2 = bell on/off bit 3 = extended kbshift so if you don't like that the Key klick disturb your SOUND so just CLEAR the BIT 0 of adr. 484 (hexa) in Assembler use BCLR #0,$484 BSET #0,$484 FRED
1224.2	6850 register bits are different on READ	PRNSYS::LOMICKAJ	Jeffrey A. Lomicka	`Mon Dec 30 1991 10:38`	6
	The 6850 register bits mean something totally different when you READ them as when you WRITE them, so you can't just save/restore their contents. I think the correct contents are either 0x81 or 0x82. Bit 7 is the interrupt enable, and bits 1&2 control the baud rate (�16 or �64), and the other bits are the modem controls. I have the actual bit definitions at home. I'll try to remember to bring them in.
1224.3	dis/enable keyboard.	IJSAPL::KDEVRIES	Kees de Vries	`Mon Jan 06 1992 03:56`	11
	.1 and .2 put me on the right track. The ACIA control register contains a lot more bits. After some experiments I figured out that communications between ST and keyboard processor is 8 bits, no parity , 1 stop bit, speed :64. To disable keyboard 0x16 to 0xfffc00. (including mouse , joystick) To enable keyboard 0x96 to 0xfffc00. Kees de Vries.
1224.4		PRNSYS::LOMICKAJ	Jeffrey A. Lomicka	`Tue Jan 07 1992 13:12`	2
	Glad you got it figured out. When I went back to reply with real numbers, the conference got weird and I didn't get back in until today.