Re: A86: Inferred timing...Help!!

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Re: A86: Inferred timing...Help!!

At 06:48 PM 10/9/97 -0400, you wrote:
>> the linkport has two data lines.  How do you want them to flicker?  Tell me
>> that and I'll do it.
>
>I made some code that fickers both the white and red lines on and off at
>the same time. I only need you to help me optimize it. While run this
>code I'm going to hook the linkport up to a osciscope (whatever, I cant
>spell) to determine the fastest the linkport can run under asmbly. With
>this information I'll be able to make an inferred link that will funtion
>under fast transfer asmbly programs. See if you can find anyway to
>optimize this code for speed: 
>	-Michael
>#include "asm86.h"
>#include "ti86asm.inc"
>
>.org _asm_exec_ram
>
>	call _clrLCD
>	ld hl,$0000
>	ld (_curRow),hl
>	ld hl,title
>	call _puts
>        ld c, $07     
>Port_loop:
>	ld b, $FC
>	out (c),b
>	ld b,$C0
>	out (c),b
>	jp keyloop
>
>keyloop:
>	call $5371
>	cp $37
>	jr z,quit
>	jp Port_loop
>
>quit:
>	ld b,$C0
>	out (c),b
>	ret
>	
>title:
>	.db "                     "
>	.db "  Michael Malluck's  "
>	.db "      PortTest       "
>	.db "       V 2.5         "
>	.db "                     "
>	.db " Press exit to exit  ",0
>	
>
>.END
>.END
>.END


Yeah, this can be optimized.

this is just the loop part:

Loop:
	ld a,$FC		;these two lines put out $FC to link
	out (7),a
	ld a,%00111111		;this is the mask for the keycheck
	out (1),a		;put iot out keypad port
	ld a,$C0		;now we switch link port
	nop
	nop
	nop
	nop			;to make the timing between the switches more 
				;equal
	out (7),a		;back to what it was
	in a,(1)		;now check key
	bit 6,a			;this checks for exit
	ret nz			;return to TI-os
	jr Loop

7+11+7+4+4+4+4=41       ;after first switch  (t-states)
11+8+5+12+7=43		;after second switch  (t-states)

this is probably the best possible routine.  If you ever are hoping to get
good time out of anything, don't call $5371, or call GET_KEY   Neither do
you want to call _getKey.

Those are both bottlenecks and will slow everything down.


The keycheck works, trust me on that, if you want to know how, i'll tell
you later.




-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 Alan Bailey            mailto:bailela@charlie.cns.iit.edu
 IRC:Abalone              Web:http://www.iit.edu/~bailela/
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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