more on the HFC saga

[Marc Weinstein]

>From article <1991May23.003857.8878 at blilly.UUCP>, by bruce at balilly (Bruce Lilly):
> In article <1991May22.041659.13189 at fithp> mhw at fithp (Marc Weinstein) writes:
>>
>>I'm beginning to think that there *ARE* select PCs out there which may
>>just be able to handle these higher throughputs.  I know of at least
>>one 3b1 which can communicate with a Sun using V.42bis, 19200 port rate,
>>and sees ~1800 Bps with no data corruption.
> 
> OK (remember, this is speculation, not hard facts): According to the
> Device Driver Development Guide, the last driver to be installed has its
> interrupt service routine(s) placed at the beginning of the interrupt
> "chain".

How do you reorder the devices drivers in the chain?

> I'm not sure how the built-in driver for /dev/tty000 is
> linked into the interrupt service chain, but that might be another
> pertinent factor.

Hmmm - we use tty000.  We could switch to a combo board tty, but we
figured that tty000 *should* have the best response.

> Other possible factors are the version of the OS, hardware revision
> levels, kernel modifications

Has anyone seen any correlation with any ktune parameters??

> (such as the patch to speed up response to
> keyboard input, which might slow down response to tty interrupts),

We were under the impression that this patch was NOT just for keyboard
input, but was for ANY character I/O device.  Is this not the case?

We could swear our tty I/O improved with the patch in place.

-- 
Marc Weinstein
{simon,royko,tellab5}!linac!fithp!mhw		Elmhurst, IL
-or- {internet host}!linac.fnal.gov!fithp!mhw