165 to late MAF

[Peter Gargano]

Not wishing to labour the point (Craig said it all), and as I have all the
code right here, right now...

Thomas Matthews wrote:
> 
> Then either the hack is wrong, or it is a unused part of code, or the ECM
> has its own Voltage to frequency converter.

Well you're sort of right - but The Hac IS CORRECT, and the ECM has a converter,
but it's all in software - no F->V hardware, just a read of the A/D converter.

Check the SOURCE!... (ECMguy's HAC)

LC014:  FCB     $B4     ; 1011 0100      Air Fuel Opt Word 1, ($B4)
                        ;
                        ; b7 = Use Filter for Air flow
                        ; b6 = Use TCC for Shft Lamp Cnt'l
                        ; b5 = Req Clsed Lp for Can Purge
                        ; b4 = VATS Enable
                        ;
                        ; b3 =
                        ; b2 = Analog MAF Meter in use (vs FM DIGITAL)
                        ; b1 = Single Fire Mode
                        ; b0 = Manual Xmission
                        ;

==== and

;   Calc Air flow Fm MAF Air meter
;
; ESTABLISH 1 of 2 TYPES OF MAF, ANALOG (0 5 VDC)
; OR DIFITAL ) 32 Hz to ___ Hz)
;
;******************************************************

        ;
        ; CK AFR MD WD1 FOR ANALOG MAF
        ;
LF76A:  LDAA    LC014           ; Fuel/Air Mode Wd 1
        BITA    #$04            ; b2, ANALOG MAF
        BNE     LF7AC           ; BR IF b2, (ANALOG MAF )
                                ; ... else
        ;
        ; DIGITAL (FM) MAF
        ; (OLD BOSCH TYPE)
        ;
        LDD     L00ED           ; 8 cntr Lps MAS


==== and

;**************************************************
; ANALOG MAF
;
; MULT ANALOG VAL x 7 TO LOOK
; LIKE FM MAF AND USE FM TABLES
;**************************************************
LF7AC:  LDAA    #$A0            ; A/D Ch A, Mass Air Sensor
        JSR     LF1BE           ; To A/D subroutine

etc..

Sorry to those who find code a bit of a bore.
-- 
Peter Gargano