Measurement Computing PCI-DIO48H/CTR15 - Manual (Page 9)

See Figure 3-3 for a translation diagram of the upper half (pins 51 to 100) of the
C100FF-xx cable to the second 50-pin connector.
Figure 3-3. C100FF-xx Pin-to-Pin Translation 51-100 to 1-50
IMPORTANT NOTE
This board emulates the 8255 chip. The 8255 emulation initializes all
ports as inputs on power-up and reset. These inputs typically will float
high and may have enough drive current to turn on any connected
devices.
If it is important that the outputs go to an OFF state (or an ON state) on a power-up or
reset, you must use pull-down resistors (or pull-up resistors for a mandatory ON
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