UberTeg

I've been messing around with an obd1 P75 ecu. As of now, I can add a speed/rev limit table (different rev limits for different speeds), and I *think* i can add boost tables. I have 2 ideas in my head for boost. The first involves the AFC hack principal. The CEL comes on when the map sensor's voltage reaches 0xA1 (~1psi). I can change this error code to add a boost map. Think of it this way:

//map hook
if in boost
{
cut 40% off map
if !boost_flag
{
boost_flag = true
}
}
else
{
if boost_flag
{
boost_flag = false
}
}

//fuel table hook
if boost_flag
{
Load Boost Map
}
else
{
Load N/A Map
}

//ign table hook
if boost_flag
{
Load Boost Map
}
else
{
Load N/A Map
}

So when you reach ~1psi, the code would automaticlly cut 40% off the map and use seperate maps for boost. This would keep the stock n/a map's resolution the same (unlike the normal afc hack) for precision tuning of both n/a and boost. The only thing i'm worried about is the transition from n/a maps to boost maps.

My second method, the harder one that i'm still working on, involves re-sizing the the maps and let the ecu select them on their own. Of coarse this would require i remove the MAP sensor voltage range check (very easy). The only potential problem I foresee with this, is the pointer to the appropriate fuel/ign map. Stock is 10x20 (200 total) is pretty close to the limit of 8 bit (255). I *think* its using 16-bit pointers cuz of the instructions its using. I need to test it on a car.

Heres the map sensor code:
0841- E5 BA : L A, BA
0843- 83 : SWAP
0844- F5 06 : LB A, 06
0846- C6 A1 : CMPB A, #A1 //see if map sensor is above ~1psi
0848- C8 04 : JGT 084E
084A- C6 0B : CMPB A, #0B
084C- CD 07 : JGE 0855
084E- C5 B0 18 : SB B0.0 //sets the CEL cuz map was above 1psi, or below #0b
0851- F4 35 : LB A, off 35
0853- CB 09 : SJ 085E

A few nops or a jmp could take care of that CEL ^^

Does anyone kno anyone who is selling an obd1 P75 for a reasonable price? I dont want to start hacking up my current ecu because i'm a college student and this is my only transportation. If it works, eprom's only cost about $3, cheaper if you buy in bulk. This could make goign forced induction super cheap if you are obd1. And you can tune it yourself with an eprom burner (I got mine for $80). So what do you guys think?