Vector Imagery

[Tony Duell]

> Just seems strange - but I wonder if it was a marketing move and they 
> deliberately crippled the port? Maybe there was some plan for an I/O board 
> that could be sold (doubtless at great expense) to anyone wanting to use their 
> PC for control purposes.

There is (or was). The Data Acquistiion Adapter. It includes a 16 bit 
parallel I/O port, ADC, DAC, etc. I have one, the user manual and the 
techref.

The connector on the bracket is, IIRC a DC62. There was a breakout panel 
that I don't have to link it to your hackery. I do have the loopback 
plug (for testing), and of course the techref gives the pinouts.

> In fact, maybe that was another intended use (which never happened) for the 
> board that's used to connect a PC to the expansion chassis? (I've never seen 
> or looked at details of one of those boards - but presumably it's full of 
> generic I/O lines)

The expansion chassis interface is basically a load of buffers for the 8 
bit ISA bus lines. Cards in the expansion chassis appear as they would if 
they were in the main machine.

-tony