Multiple lots, all having the same recipe, being batched together in the tool's import port led to frequent mistakes when new lots with different recipes came along. Setup a strict queuing regimen for what was allowed to be seen on the tool's input port. Alarmed if mixed recipes would be processed together, and otherwise automatically changed recipes on the tool for new material.

Had fussy product mix requirements due to chamber seasoning needs. Interface with "Triant" software package in passthrough mode for corporate tool commonality.

A finicky rs232 interface would often hangup the tool at lot finish. Halted polling at end of last wafer until wafer movement completed.

Monitored conditioning wafers, tube and liner lifetimes, and prevented wandins if limits were exceeded

Walking up to a tool, you didn't know whether it was done processing or not.

Converted from binary to ascii recipe definitions for easier engineering recipe auditing.

It was hard to figure out which wafers got processed if a power failure occured. Made little "wafer" circles, which turned light green upon chamber entry and dark green upon exit.

Simple recipe selection on a given furnace tube of a cluster tool.
Used $400. Hume Integration software for low level TCP/IP hsms gem protocol handling.