I'm trying to set-up my shift light to come on at desired rpm. The '8746 hac is not so well commented in this area, has anyone fleshed more of this out -- or is there a better documented hac for the '8746 around ?
The $42 hac has similar tables and good comments -- just not sure if they really are the same constants. thx.
;*==================================================
;* Shift Light Parameters
;*
;* Indexed tbl + 19
*==================================================

LD4F9: FCB 160 ; 1st gr n/v
FCB 99 ; 2nd gr n/v
FCB 65 ; 3rd gr n/v
FCB 49 ; 4th gr n/v**

FCB 100 ;
FCB 66 ;
FCB 50 ;

LD500:
FCB 35 ;
FCB 38 ;
FCB 39 ;
FCB 42 ;
FCB 51 ;

FCB 128 ;
FCB 128 ;
FCB 128 ;
FCB 128 ;
FCB 209 ;
FCB 13 ;
FCB 16 ;
FCB 176 ;

; ----------------------

LD50D: FCB 10 ;
LD50E: FCB 15 ;

 

Took a closer look at the $42 hac and migrated over some of the comments that looked similar. Forgot to mention this was using the $61 mask. Since I'm only concerned with the shift light during WOT operation I think there is only one value located at 0x50C that needs to be set at desired rpm (val*25).

LD500:
FCB 35 ;
FCB 38 ;
FCB 39 ;
FCB 42 ;
FCB 51 ;
;*---------------------------------------------
;* 0 - 2 Mult for adj tps
;* Relative to Current gear, (n/a for auto)
;*---------------------------------------------
FCB 128 ; 1.0 adj to tps in 1st gear
FCB 128 ; 1.0 adj to tps in 2nd gear
FCB 128 ; 1.0 adj to tps in 3rd gear
FCB 128 ; 1.0 adj to tps in 4th gear

FCB 209 ;

FCB 13 ; 260 mvdc TPS, Light is OFF below thresh for LOWER gear
FCB 16 ; 320 mvdc TPS, Light is OFF below thresh for HIGH gear
FCB 176 ; 4400 RPM, Light always enabled above thresh

 

Yes, the value at $50C is to be used for the WOT shift light term. I worked on this a bit this morning and just returned to it. There are four tables that need to be set to zero to prevent the light from coming on at other times.

There is a MPH term that is hardcoded and can not be changed (in ROM). The shift light will not work unless the vehicle speed is over 5 MPH. Need to keep this in mind.

Here is what I would do ($61 maskID):

Set $509 to 255, -40 c
Set $50A and $50B to 0, 0 TPS%
Set $50C to the desired shift light RPM/25 ***
Set $50D and $50E to 0, no time delay

The four tables to zero (11 bytes per table) are at:

$4C5
$4D0
$4DF
$4EA

And that should do it. I haven't benched this, only went through the code. But It shouldn't be too far off.

RBob.

 

Informative post even for a guy that has an auto .