Re: A89: TI89 ROM vs. HP49 ROM

To: <assembly-89@lists.ticalc.org>
Subject: Re: A89: TI89 ROM vs. HP49 ROM
From: "Scott Noveck" <noveck@pluto.njcc.com>
Date: Tue, 8 Jun 1999 23:21:16 -0400
Delivered-To: assembly-89-outgoing@towerguard.unix.edu.sollentuna.se
Delivered-To: assembly-89@lists.ticalc.org
Reply-To: assembly-89@lists.ticalc.org

>Scott Noveck wrote:
>> Yes, the TI89's ROM is written in (slow and bloated) C, with the CAS core
>> coming from the commercial software Derive.  The HP49's speed is
comparable
>> because it was written in almost all Saturn ASM.
>
>Isn't also the HP's cpu specialized for floating point?
>That also would explain why it is so much faster in things like graphing
and
>such.

Not neccessarily floating point per se, but BCD floating point.  There are
several different ways to represent floating point numbers, BCD (Binary
Coded Decimal) is found in most HPs and TIs.  The HP48/49's Saturn processor
specializes in both RPN and BCD numbers, so HP uses those.  The problem is
that TI does, too - the 68k processor was NOT meant for BCD and loses all of
its 16- and 32-bit calculation abilites on BCD numbers (according to what
I've read).  HP has no advantage by using BCD, it's just that TI was
incredily naive in doing so. . .