is it possible to emulate keypresses from software?

jotd · 27 October 2015, 22:42

Hi,

Well I guess not, but maybe I'm wrong...

thomas · 27 October 2015, 23:01

Sure it is possible. How do you think that keyboard drivers would work, for example for USB keyboards?

Check input.device / IND_WRITEEVENT

Of course this only works with AmigaOS programs, not with games which access the hardware directly.

gulliver · 27 October 2015, 23:50

I use Keypressed for that purpose.

http://aminet.net/util/batch/KeyPressed.lha

jotd · 28 October 2015, 07:21

thanks, but I meant in a non os friendly environment (games)

meynaf · 28 October 2015, 09:37

Why can't you just locate where the program is accessing the keyboard and put a patch there ?

Toni Wilen · 28 October 2015, 19:43

Not tested idea:

Disable interrupts
Write very small value to CIA-A timer A.
Set CIA serial port to output mode (Set bit 7 of CRA)
Start timer (which does nothing yet because output mode is active)
Write keycode you want to inject in SDR. (Serial port transmit starts, transmit rate = timer A)
Wait a bit to guarantee end of transmit. (Don't touch ICR!)
Restore timer A if needed.
Enable interrupts

Unfortunately simply writing keycode to CIA serial port register is not enough because it does not generate any interrupts and there is no other way to generate SP (serial port) interrupt than a) using serial port in output mode and transmitting data to keyboard (which keyboard ignores, output mode is normally used only for keyboard handshake).

Uses small timer value (I guess 1 is smallest possible) to make serial port transmit as fast as possible. All this complexity to get SP interrupt request bit set... (Which most keyboard interrupt handlers check before reading SDR)

jotd · 28 October 2015, 23:23

@meynaf: yeah, but I want to make a generic handler, not rewrite all patches done for games (it's for a possible cd32 loader project using whdload slaves & RN CD loader)

@Tony: I was waiting for an answer from the Boss

thanks. I understand that we trigger a timer interrupt instead of a keyboard interrupt, which is the same vector.

Well this should be tested on a real amiga as well! WinUAE could just be nice and work, whereas the real thing wouldn't.

BTW how the handler distriguishes between timer interrupts and keyboard interrupts?

Toni Wilen · 29 October 2015, 08:34

No, it should generate correct keyboard serial port interrupt, SP flag in CIA ICR should become activated (unfortunately it can't be set by CPU write, like INTREQ can be both set and cleared with CPU write).

Check HRM CIA chatper, it has short serial port output mode description. (Timer A = CIA serial port baud rate generator in output mode, in input mode it is not used by serial port)

I'll do real hardware test later.

thomas · 29 October 2015, 11:29

This is a nice experiment, but it has no practical use. You can only inject one key code before the game starts. Once the game has taken over the system, there is no multitasking any more and no way for your program to get control. You can only hope that the game does not overwrite the interrupt vector and that your interrupt routine is regularly called. But it surely does not make a generic handler.

meynaf · 29 October 2015, 11:38

Good remark !

Either it's an environment where the OS still runs (in that case using input.device is the solution) or it's an "OS kill" environment - and then no interrupt survives...

Why wanting to force games to detect fake keypresses anyway ?

Toni Wilen · 29 October 2015, 11:39

I think the point is to allow generic injection of keycodes without knowing how the game/demo reads them = you already have some control of running code (for example via some other patch, probably has something to do with JST

) and you want to inject key presses/releases without need for another game/demo specific patching.

meynaf · 29 October 2015, 11:44

This does not answer the question : why wanting to inject key codes ?

I would understand the need to inject joystick changes - to emulate it with the keyboard, for example. But inject key codes ?

Toni Wilen · 29 October 2015, 11:47

I am not OP but one possibility that makes sense is running games that need keyboard on CD32 or CDTV using joypad to send key codes.

EDIT: Why does it need some purpose? Weird and possibly pointless "classic" Amiga stuff is fun.

meynaf · 29 October 2015, 11:54

It's often easier to find a solution when the exact purpose is known.

jotd · 29 October 2015, 13:16

you're both right.
In that case, it's to be able to reuse somehow whdload slaves with a kind of JST/Whdload on CD32 to send keypresses from the extra joypad buttons.
If it cannot be done, then all slaves which need extra keys will need to be patched manually as we happen to do.

Toni Wilen · 01 November 2015, 13:20

It seems to work. Test code below (Injects keys a, b and c). Real A1200 confirmed. (Also work in UAE)

Code:


	move.l 4.w,a6
	lea keycodes(pc),a4
l6
	; Disable interrupts
	jsr -$78(a6)
	
	; Timer value = 10 (Just randonly chosen value)
	move.b #10,$bfe401
	move.b #0,$bfe501
	; OUTMODE and START
	move.b #$41,$bfee01
l1
	; Write keycode
	move.b (a4)+,$bfec01

	; Delay until keycode transmit is complete
	; (Can't poll CIA interrupt register because it also clears it)
	moveq #10-1,d2
l4
	move.w $dff006,d0
	clr.b d0
l3	move.w $dff006,d1
	clr.b d1
	cmp.w d0,d1
	beq.s l3
	dbf d2,l4

	; Stop timer
	bclr #0,$bfee01

	; Enable interrupts
	jsr -$7e(a6)

	; Wait until keyboard interrupt
	; handler has handled the keycode
	; = outmode was cleared.
l5
	btst #6,$bfee01
	bne.s l5

	cmp.b #$ff,(a4)
	bne.s l6

	rts

keycodes
	dc.b ~($20<<1+0),~($20<<1+1) ;A press,A relase
	dc.b ~($35<<1+0),~($35<<1+1) ;B
	dc.b ~($33<<1+0),~($33<<1+1) ;C
	dc.b $ff

NOTE: Timer-A will run normally (Output mode or not), generating interrupts normally. Writing to serial port (SDR) won't automatically start or stop it. Extra CIA-A interrupts may cause problems if you are not careful.

jotd · 01 November 2015, 20:42

Excellent! Thanks for the code

jotd · 05 May 2018, 14:27

Toni, this code works very well, but on some games which already use CIA timer A it has some bad side effects.

For instance, in Fire & Ice, if we send key presses like that, the music is frozen.

I tried (and failed) to store the previous values of the timers. Maybe some stuff is write only or whatever, because it doesn't work, like at all (crashes winuae!!)

note that I'm not disabling the interrupts at all in this code.

Code:

send_key_event

	; Disable interrupts: no need here: we are in VBL
	movem.w	d3-D5,-(a7)
  
       ;; JOTD changes to stop timer & save values (doesn't work!!)
	move.b	$bfee01,d5		; save CIAACRA value
	bclr #0,$bfee01			; stop timer
	move.b	$bfe401,d3
	move.b	$bfe501,d4
        ;; end of JOTD changes
	
	; Timer value = 10 (Just randonly chosen value)
	move.b #10,$bfe401
	move.b #0,$bfe501
	; OUTMODE and START
	move.b #$41,$bfee01
l1
	; Write keycode (keypress only)
	rol.b	#1,d0
	not.b	d0
	move.b d0,$bfec01

	; Delay until keycode transmit is complete
	; (Can't poll CIA interrupt register because it also clears it)
	moveq #10-1,d2
l4
	move.w $dff006,d0
	clr.b d0
l3	move.w $dff006,d1
	clr.b d1
	cmp.w d0,d1
	beq.s l3
	dbf d2,l4

	; Stop timer
	bclr #0,$bfee01

        ;; JOTD changes to put previous values in timer & control regs
	move.b	d3,$bfe401
	move.b	d4,$bfe501
	move.b	d5,$bfee01
	movem.w	(a7)+,d3-D5
	
	rts

Galahad/FLT · 05 May 2018, 14:49

Can you not simply do a selectable option at the start where user selects Timer A or Timer B operation?

jotd · 05 May 2018, 15:25

Pretty good idea actually ! I'd prefer a generic solution but if it's not possible, I'll go for that instead. Brilliant.

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27 October 2015, 22:42	#1
jotd This cat is no more Join Date: Dec 2004 Location: FRANCE Age: 52 Posts: 8,389	is it possible to emulate keypresses from software? Hi, Well I guess not, but maybe I'm wrong...

27 October 2015, 23:01	#2
thomas Registered User Join Date: Jan 2002 Location: Germany Posts: 7,035	Sure it is possible. How do you think that keyboard drivers would work, for example for USB keyboards? Check input.device / IND_WRITEEVENT Of course this only works with AmigaOS programs, not with games which access the hardware directly.

27 October 2015, 23:50	#3
gulliver BoingBagged Join Date: Aug 2007 Location: The South of nowhere Age: 46 Posts: 2,358	I use Keypressed for that purpose. http://aminet.net/util/batch/KeyPressed.lha

28 October 2015, 07:21	#4
jotd This cat is no more Join Date: Dec 2004 Location: FRANCE Age: 52 Posts: 8,389	thanks, but I meant in a non os friendly environment (games)

28 October 2015, 09:37	#5
meynaf son of 68k Join Date: Nov 2007 Location: Lyon / France Age: 51 Posts: 5,365	Why can't you just locate where the program is accessing the keyboard and put a patch there ?

28 October 2015, 19:43	#6
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,575	Not tested idea: Disable interrupts Write very small value to CIA-A timer A. Set CIA serial port to output mode (Set bit 7 of CRA) Start timer (which does nothing yet because output mode is active) Write keycode you want to inject in SDR. (Serial port transmit starts, transmit rate = timer A) Wait a bit to guarantee end of transmit. (Don't touch ICR!) Restore timer A if needed. Enable interrupts Unfortunately simply writing keycode to CIA serial port register is not enough because it does not generate any interrupts and there is no other way to generate SP (serial port) interrupt than a) using serial port in output mode and transmitting data to keyboard (which keyboard ignores, output mode is normally used only for keyboard handshake). Uses small timer value (I guess 1 is smallest possible) to make serial port transmit as fast as possible. All this complexity to get SP interrupt request bit set... (Which most keyboard interrupt handlers check before reading SDR)

28 October 2015, 23:23	#7
jotd This cat is no more Join Date: Dec 2004 Location: FRANCE Age: 52 Posts: 8,389	@meynaf: yeah, but I want to make a generic handler, not rewrite all patches done for games (it's for a possible cd32 loader project using whdload slaves & RN CD loader) @Tony: I was waiting for an answer from the Boss thanks. I understand that we trigger a timer interrupt instead of a keyboard interrupt, which is the same vector. Well this should be tested on a real amiga as well! WinUAE could just be nice and work, whereas the real thing wouldn't. BTW how the handler distriguishes between timer interrupts and keyboard interrupts?

29 October 2015, 08:34	#8
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,575	No, it should generate correct keyboard serial port interrupt, SP flag in CIA ICR should become activated (unfortunately it can't be set by CPU write, like INTREQ can be both set and cleared with CPU write). Check HRM CIA chatper, it has short serial port output mode description. (Timer A = CIA serial port baud rate generator in output mode, in input mode it is not used by serial port) I'll do real hardware test later.

29 October 2015, 11:29	#9
thomas Registered User Join Date: Jan 2002 Location: Germany Posts: 7,035	This is a nice experiment, but it has no practical use. You can only inject one key code before the game starts. Once the game has taken over the system, there is no multitasking any more and no way for your program to get control. You can only hope that the game does not overwrite the interrupt vector and that your interrupt routine is regularly called. But it surely does not make a generic handler.

29 October 2015, 11:38	#10
meynaf son of 68k Join Date: Nov 2007 Location: Lyon / France Age: 51 Posts: 5,365	Good remark ! Either it's an environment where the OS still runs (in that case using input.device is the solution) or it's an "OS kill" environment - and then no interrupt survives... Why wanting to force games to detect fake keypresses anyway ?

29 October 2015, 11:39	#11
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,575	I think the point is to allow generic injection of keycodes without knowing how the game/demo reads them = you already have some control of running code (for example via some other patch, probably has something to do with JST ) and you want to inject key presses/releases without need for another game/demo specific patching.

29 October 2015, 11:44	#12
meynaf son of 68k Join Date: Nov 2007 Location: Lyon / France Age: 51 Posts: 5,365	This does not answer the question : why wanting to inject key codes ? I would understand the need to inject joystick changes - to emulate it with the keyboard, for example. But inject key codes ?

29 October 2015, 11:47	#13
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,575	I am not OP but one possibility that makes sense is running games that need keyboard on CD32 or CDTV using joypad to send key codes. EDIT: Why does it need some purpose? Weird and possibly pointless "classic" Amiga stuff is fun.

29 October 2015, 11:54	#14
meynaf son of 68k Join Date: Nov 2007 Location: Lyon / France Age: 51 Posts: 5,365	It's often easier to find a solution when the exact purpose is known.

29 October 2015, 13:16	#15
jotd This cat is no more Join Date: Dec 2004 Location: FRANCE Age: 52 Posts: 8,389	you're both right. In that case, it's to be able to reuse somehow whdload slaves with a kind of JST/Whdload on CD32 to send keypresses from the extra joypad buttons. If it cannot be done, then all slaves which need extra keys will need to be patched manually as we happen to do.

01 November 2015, 20:42	#17
jotd This cat is no more Join Date: Dec 2004 Location: FRANCE Age: 52 Posts: 8,389	Excellent! Thanks for the code

05 May 2018, 14:49	#19
Galahad/FLT Going nowhere Join Date: Oct 2001 Location: United Kingdom Age: 50 Posts: 9,020	Can you not simply do a selectable option at the start where user selects Timer A or Timer B operation?

05 May 2018, 15:25	#20
jotd This cat is no more Join Date: Dec 2004 Location: FRANCE Age: 52 Posts: 8,389	Pretty good idea actually ! I'd prefer a generic solution but if it's not possible, I'll go for that instead. Brilliant.

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