Date: Mon, 10 Apr 1995 14:31:21 +0100 (BST) From: Paul Richards <paul@isl.cf.ac.uk> To: rgrimes@gndrsh.aac.dev.com (Rodney W. Grimes) Cc: gurney_j@efn.org, terry@cs.weber.edu, matt@lkg.dec.com, vernick@cs.sunysb.edu, freebsd-hackers@FreeBSD.org Subject: Re: PCI/EISA/ISA performance Message-ID: <199504101331.OAA25191@isl.cf.ac.uk> In-Reply-To: <199504060650.XAA02656@gndrsh.aac.dev.com> from "Rodney W. Grimes" at Apr 5, 95 11:50:21 pm
next in thread | previous in thread | raw e-mail | index | archive | help
In reply to Rodney W. Grimes who said > > > > > On Tue, 4 Apr 1995, Rodney W. Grimes wrote: > > > > [...] > > > > > ISA does not have a specified clock frequency, I have seen it running > > > as fast as 16Mhz. Most boards die above 10Mhz, but some of the more > > > specialized industrial applications boards are spec'd upto 12 or 16Mhz. > > > > actually... I think that I am currently running my isa bus at 16mhz... I > > think for a while I was tring to run the bus at 20... but it was falling > > over and wouldn't boot... and this is with ne2000 clone cards... and > > other generic cards... > > I suspect you are off by a factor of 2, I haven't seen a ``generic'' > card of any sort that would run at 12Mhz, let alone 16Mhz. IDE controllers > are famous for falling over above 10Mhz (ever done a transmission line > simulation of an unterminated ribbon cable :-)). I've run an ISA bus at 16 Mhz and the only card that failed was a really old Isolan ethernet card. A newer version of the card worked fine as did my IDE and graphics card. I only ran it for a brief period though since I didn't want to risk it long term. I just tried it to see if it would work at all. > Also what BIOS is it? AMI, Pheonix, AWARD or someone else. > > Realize a 486DX33, 486DX2/66 and 486DX4/100** all run with a CPUCLK of > 33 Mhz. A 486DX25, 486DX2/50 and 486DX4/75 all run with a CPUCLK of > 25 Mhz. A 486DX50 runs with a CPUCLK of 50Mhz. > 486DX33 with AMI bios. -- Paul Richards, FreeBSD core team member. Internet: paul@FreeBSD.org, URL: http://isl.cf.ac.uk/~paul/ Phone: +44 1222 874000 x6646 (work), +44 1222 457651 (home) Dept. Mechanical Engineering, University of Wales, College Cardiff.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199504101331.OAA25191>