Interesting pic. I do not have experience with the Accel DFI system. A google search indicates the ECM you posted pics of is the DFI VI (6) system, which appears to be discontinued.

I'm guessing...

The stock factory 1993 GM computer is not designed for Supercharger Boost. Typically, aftermarket computers designed to optimize Supercharger Boost performance will not control or operate a computer...

I would think the original computer for the 93 Silverado would have been the 16168625 with a 4L60E http://www.gearhead-efi.com/Fuel-Injection/showthread.php?336-16168625-PCM-Information-E6
or the...