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Over 30 years ago, I was doing some OS9 (Microware, not Apple) development on a 68k embedded target. I needed a PIO driver that could do bi-directional I/O. T
by anonymousiam 5y ago
Over 30 years ago, I was doing some OS9 (Microware, not Apple) development on a 68k embedded target. I needed a PIO driver that could do bi-directional I/O. The OS came with a PIO driver, but it wouldn't let you switch directions. I approached the vendor with several options:
1) I will pay you to write another driver with this functionality.
2) License the driver source code to me and I will do it.
For reasons I do not remember, they would not do either.
I ended up reversing their PIO driver and implementing a version with the functionality I needed. I was uneasy about doing this, but we never sold or distributed the work so it was probably legal. (The development was for an in-house application with just one target.)