30 Dec
1998
30 Dec
'98
1:55 p.m.
<> Yes. The 8259 PIC (interrupt controller) is fully programmable for edge
<> and level. It's possibel to go from edge to level on a common PC but you
<
<
<Unfortunately the interrupt inputs on the 8259 are always active high
<(specified clearly in the data sheet), so you still need inverters on all
<the inputs for active-low lines.
Yes and they would be needed as putting raw unbuffered mos inputs on a
bus is bad form.
<all, the reason for having a PC is compatibility. There are plenty of
<nicer machines to hack about with (which is where we started).
yes, multibus and other implmentations were better. Even S100 got that
part right!
Allison