Back again. The trip to Skycrafters in Orlando did not yield any ZIF sockets, but they did have some regular 28pin sockets. So, a few dollars lighter in the wallet, I returned home with a few and can make a little more progress.
Took a few of the CalProm'* and installed sockets on them in place of the EPROM. The sockets were of the machined pin variety, which don't bend very well, so I had to file slots in the side of the CalProm carrier to get a soldering iron in and install them.
Here'* a finished one ready to use:
The socket fits low enough that even with an EPROM in the socket, the blue plastic cover will fit over the CalProm.
For EPROM chips, I'm going to be using all recycled ones. The chips removed from the CalProms along with a bunch of chips salvaged from old PC motherboards. If you find 286 or 386 motherboards, you are likely to find the same 27C256 EPROM chips in use as the boards BIOS. Just peel back the foil cover on the chip and take a peek at the part number. Old 486 motherboards usually have 27C512 EPROM chips on them. No good for this project, but it would be the same chip as found in the 93-95 L67 ECM'* and possibly the L27 N/A motor'* ECM as well.
To make a chip ready for use, I'll be running them through a UV Eprom Eraser. When exposed to ultra-violet light for a few minutes, all the transistors that make up the memory cells of the EPROM go to a logic high state (binary 1). That'* a blank EPROM ready for use...the value of every data byte in it is "11111111". When the chip is programmed on the EPROM burner, all the cells that need to be "0" are juiced with current, leaving the rest of the bits alone. Do you really need to know this? Probably not. But before you program an EPROM with the new software for the car, be sure to blank check it on your burner to make sure there isn't any stray data on it...who knows what the car will do with some random screwed up bits in it'* brains.
Ok, enough with the soldering iron and electrical engineering speak...(Honest, the next time I pick up a soldering iron in this project will be to join together parts of the wiring harness to fit the new motor!)
Time to do the first test this weekend, I'm a little behind schedule, but I still need to make a few simple changes to the ASSK calibrator prom code to make sure the programming software is working correctly. What I'm going to do is alter the following values:
VSS Cutoff and resume values (the vehicle speed where the ECM turns off the injectors) from 115mph to their maximum values.
RPM Cutoff and resume values (the built in rev limiter) to raise it about 500 PRM over stock.
The fan temps, turn them on about 10 degrees lower than stock.
and last, the Speedometer calibration values. Thanks to the influx of motorcyclists around Daytona, there'* a lot of radar signs around. I've passed by a few and noticed that the indicated speed on the speedometer is higher than the true vehicle speed by about 3 mph at 60, so I'll make a little adjustment and run past the same signs again to see if the speedometer is running closer to true speed. This is probably due to the small difference in tire diameters.