02-07-2016, 09:20 PM
04-13-2016, 09:36 AM
Hi Nate,
In short, no, FI is the Flag Input line.
I'll add that this is the obscurest and most poorly documented line from the I/O interface. :-)
It's used only by peripherals (PRINTER, HP-IL, WAND, etc) when requesting service from the CPU and is held high for a full digit time (four clock bit time cycles). The exact digit when the FI line is high informs the CPU of the type of service/periphera requesting service.
To the best of my knowledge, apart from said peripherals, only the CL CPU (for obvious reasons) and the USB-41 (to simulate 82143A printer) handle this line. It has no use on ROM pacs or any other module.
Cheers from Canary Islands.
Diego.
In short, no, FI is the Flag Input line.
I'll add that this is the obscurest and most poorly documented line from the I/O interface. :-)
It's used only by peripherals (PRINTER, HP-IL, WAND, etc) when requesting service from the CPU and is held high for a full digit time (four clock bit time cycles). The exact digit when the FI line is high informs the CPU of the type of service/periphera requesting service.
To the best of my knowledge, apart from said peripherals, only the CL CPU (for obvious reasons) and the USB-41 (to simulate 82143A printer) handle this line. It has no use on ROM pacs or any other module.
Cheers from Canary Islands.
Diego.