A possible bug in pdp1.c

[Bill E]

In the iot() function, it does:

if(!pulse && (dev&070)==030) IO = 0 ;

before the IOT is executed.

It would seem that this means that any IOT 03x would have the IO cleared.

Should this have been dev & 037? Or is there something else going on?

(IO means the IOT register)

Bill

[Angelo Papenhoff/aap]

The schematics say this is what should happen. the signal 3X-TP 7-4 generates the pulse 0->IO ON IOT, which also happens on TYI.

It's one of these signals that external devices can use, like PC increment as well.