27 Oct
2001
27 Oct
'01
4:43 p.m.
I have the IIT FPU on my 24 MHz '286 board. It really does a good job, obsolete
though it is. It runs at full speed in that application.
Dick
----- Original Message -----
From: "Carlos Murillo" <cmurillo(a)emtelsa.multi.net.co>
To: <classiccmp(a)classiccmp.org>
Sent: Saturday, October 27, 2001 8:16 PM
Subject: Re: VLB SCSI?
At 12:17 AM 10/28/01 +0100, Iggy wrote:
I've got an IBM-made OEM machine (mine is
branded by Lap Power) with a big
daughter-board with seven or so ISA slots and three VLB slots. The mobo
features a Blue Lightning processor and parity RAM.
-snip-
Oh, it had an all-plastic DLC-33 FPU from IIT,
too.
I liked IIT FPU's. Long before MMX, they had things like 4x4
matrix multiply instructions (for implementation of 3D homogeneous
transforms, rotation/scaling & such). And they were better at
raw computations than the corresponding ix87 part. I remember
hand-coding some robot control laws using those instructions.
Even though the scaling row is usually left unused in robot apps
(but it still is used for computations in the IIT FPU), thus
producing some inefficiency, the built-in 4x4 was still much faster than
a 3x4 matrix multiply algorithm.
carlos.
--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo(a)nospammers.ieee.org