AltairClone wrote:Other than Timesharing BASIC, no Altair software uses interrupts, so in general, I would not jumper anything to interrupts 0-7 or PINT.
If you want to use the serial I/O port as another terminal for Timesharing BASIC, then strap the SI pad to the desired interrupt level 0-7. SI stands for "S"erial "I"nterrupt and comes from the 6850 UART used for terminal I/O. You'll need to make sure your 2SIO ports and the serial port on the UIO are all at different I/O addresses.
RINT and WINT are the read interrupt and write interrupt lines for ACR I/O, but again, no Altair software uses interrupts for cassette I/O so I would not connect them.
I do not see the OUT, IN, and BH pads you reference on my board. Where are they located?
Mike
They're on the ACR board, not the UIO board. Quote from page 23 of the ACR manual (I don't have an ACR)
"There are three pads at the top of the board labeled "OUT", "IN" and "BH". There are eight pads at the bottom of the board numbered 0 through 7. The eight numbered pads correspond to the eight priority levels respectively. "
"You may connect the "OUT" (output device) pad to some priority level, and the "IN" (input device) pad to some priority level; or you may connect the "BH" (both devices) pad to a desired priority level for both devices. If the "BH" pad is used to set the priority level, the "OUT" and "IN" pads should not be used."