Oral History Questions

From: Eric Smith <eric_at_brouhaha.com>
Date: Thu Dec 10 17:13:06 1998

"Sean 'Captain Napalm' Conner" <spc_at_armigeron.com> wrote:
> -spc (Wants to know why IBM forgot pull up resistors on the IRQ
> controller ... )

Because they stupidly decided to make them

1) edge-triggered instead of level-sensitive

2) rising-edge-triggered instead of falling-edge-triggered

Thus, if they had pullup resistors they would tend to trigger by themselves.

Of course, this doesn't explain why they didn't have pullDOWN resistors,
or why they made those two stupid decisions in the first place.

Ugh! That's yet another reason why even though the IBM PC is technically
within the charter for this mailing list, I still refuse to consider it
a Classic.

Eric
Received on Thu Dec 10 1998 - 17:13:06 GMT