A83: Linkport stuff...
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A83: Linkport stuff...
Here it is...for you people who want it!
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POST THIS ANYWHERE, JUST GIVE ME CREDIT
First of all, the Linkport is naturally high and gets _pulled_ low. OK,
now that that's out of the way heres how to do stuff:
#1: Go into your ti83asm.inc file and find the linkport equates. Change
them to look like this:
; LINK PORT WRITE EQUATES
;
D0LD1L .equ 0D3h
D0LD1H .equ 0D1h
D0HD1L .equ 0D2h
D0HD1H .equ 0D0h
BPORT .equ 0
Now, to pull data line 0 (D0) low and keep D1 high, do this:
ld a,D0LD1H
out (0),a
To pull both low:
ld a,D0LD1L
out (0),a
I think you get the idea.
Remember that you CANNOT make any ROM calls and keep the lines pulled
low. If you make a call such as _getkey, or _puts the lines will go high.
Next, to input stuff:
To put the state of the lines into a, do this:
in a,(0)
Heres the equates:
ID0HD1H .equ 31 ;D0 & D1 high
IDOLD1H .equ 26 ;D0 low, D1 high
IDOHD1L .equ 21 ;D0 high, D1 low
IDOLD1L .equ 16 ;D0 & D1 pulled low
So, in order to wait until both lines are pulled low, do this:
loop:
in a,(0)
cp ID0LD1L
jp z,bothlow ;if they're both low, goto bothlow
jp loop ;No? continue looping
One note: Although you cannot use _getkey while holding lines low, you
CAN use direct input. Heres an example that pulls both lines low, then
releases them (high) until you hit clear:
.NOLIST
#define equ .equ
#define EQU .equ
#define end .end
#include "ti83asm.inc"
#include "tokens.inc"
.LIST
#define state 826Ah
#define address 8265h
#define address2 8266h
.org 9327h
call _clrLCDFull ;this is all pointless text
call _homeup
set textInverse,(iy+textflags)
ld hl,title
call _puts
res textInverse,(iy+textflags)
call _newline
ld hl,pressclear
call _puts
ld a,0 ;sets the initial state of the
lines
ld (state),a
loop:
ld a,0FFh ;reset keyport
out (1),a
ld a,0FDh ;pick column the keys are in according to group
out (1),a ;Required Syntax
in a,(1) ;Required Syntax
cp 191 ;check if clear is pressed
jp z,quit ;if so goto quit
call wait ;wait to slow down the speed
call changestate ;change the state of the lines
ld a,(state)
cp 0 ;if the state if 0
jp z,low ;goto low
jp high ;else goto high
low:
ld a,D0LD1L ;loads into a D0 & D1 are low
out (0),a ;sends it to port 0 (linkport)
jp loop ;return to loop
high:
ld a,D0HD1H ;loads into a D0 & D1 are low
out (0),a ;sends it to port 0
jp loop ;goto loop
changestate:
ld a,(state) ;this is pretty simple
cp 0
jp z,sethigh
ld a,0
ld (state),a
ret
sethigh:
ld a,1
ld (state),a
ret
quit:
call _clrLCDFull
call _homeup
ret
wait: ;this is the wait routine
ld hl,0000
ld (address),hl
jp loop2
inch:
ld hl,(address)
inc h
ld (address),hl
ld hl,(address)
ld a,h
cp 100 ;this number is how long it waits, the higher the
longer
jp z,doneW
jp loop2
loop2:
ld hl,(address)
inc l
ld a,l
ld (address),a
ld a,l
cp 255
jp z,inch
ld hl,(address)
ld a,(hl)
jp loop2
doneW:
ret
title:
.db "FIRST Strobe",0
pressclear:
.db "press clear",0
.end
END
If you have any questions or if something in here is wrong, email me.
Also, to get on a list of people to be email when my memxpander is done
you can email me.
Chris Brainerd
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