Subject: port-pmax/3776: cpuspeed variable on pmax 5000/260 too small
To: None <firstname.lastname@example.org>
From: Simon Burge <email@example.com>
Date: 06/23/1997 13:27:14
>Synopsis: cpuspeed variable on pmax 5000/260 too small
>Responsible: gnats-admin (GNATS administrator)
>Arrival-Date: Sun Jun 22 20:35:01 1997
>Originator: Simon Burge
Telstra Corp, Australia
>Release: NetBSD-current 970623
System: NetBSD vlad 1.2G NetBSD 1.2G (MONA) #0: Mon Jun 23 11:15:24 EST 1997 simonb@mona:/usr/src/sys-970623/arch/pmax/compile/MONA pmax
The cpuspeed variable in arch/pmax/pmax/autoconf.c has the
value 30 with is too small on the faster DECstations. One
obvious side effect of this is that when typing on a serial
console characters repeat unexpectantly because the DELAY(2)
in the scc code is much shorter than the 2us that the chip
takes to settle.
Log on to the console of a 5000/260 and type :-)
There's two different fixes:
Change the value of cpuspeed in autoconf.c to a larger
value if on an R4000 or R4400 CPU.
Actually calculate the clock speed and use that. This
code could also be used to determine whether the machine
is a 20, 25 or 33 MHz CPU for some machines.
The first is trivial, the second a bit harder...