On the 29256 PROM, there is an arrow on top in the corner. Which way should that arrow face in the programer and also in the memcal? I just wanted to make sure before I messed something up thanks

 

Arrow I don't know.
Usually there is a scallop on one side. It should match the sketch on the programmer. On the memcal the scallop should face the center. Might call it a C

edge C edge

 

It faces toward the handle on the programmer(foward) and away from the handle on a Craig Moates adapter.

Chris(had the same question)

 

Say I was to accidently solder the PROM into the memcal backwards, can I just de-solder it, flip it around and re-solder it? Or do I need to use a new PROM?

 

Provided you didn't power it up, you can flip the chip. cheers, Bob

 

What if I did?

 

Odds are if you powered up the chip backwards then its probibly been fried. Tho I have seen otherwise...give it a try, see if it will take a program. cheers, Bob

 

Some chips will use a dot/arrow/triangle in one corner to designate pin 1 on the chip.

 

Luckily I ordered 2 29C256'c so I can use the other one, but do you think the ECM was hurt? If so where can I get one tomorow or thursday? When I turn the key, the fuel pump comes on, and the SES comes on but doesnt flash. Is this because I had the PROM in backwards??

 

I've put em in backwards before in the programmer and the car, and haven't burned one up that way yet. Not to say it can't be done. Usually it's just "Why doesn't it work? Oh Crap! Whew..."

 

ROFLMAO....!!!!
That's how it's always going to be. My last time was when I got your 8 in1 and I installed the flash prom backwards. Car didn't start and I turned it off, put my finger on the prom....HOT. Took it out, blew on it a bunch to get it to cool down. Verifty it with PP2 and reinstall, works great.
The only prom I've destroyed was when I bent a prong and it eventually just broke off inside the 2 ceramic plates of the IC...oh well.