[Coco] [Color Computer] Re: OS-9 as Replacement for DECB.

[jdaggett at gate.net]

James

Whether one uses a 68881/2 or other FPU, there will be a minor interface issue and 
some patching to RSBASIC. Using higher preecisison just means that more bytes 
are required. For extended precision one needs 10 bytes for each FP accumalator. 
Currently RSBASIC uses five. 

Yes RSBASIC does not use IEEE 754 standard. The routines were written before 
they came into existance. The FP routines were written in 1980 and the IEEE754 
standard came into being in either 1984 or 1985 time frame. Yet the RSBASIC FP 
routines give 10 digit decimal accuray and precision. Basically calculator accuracy.

Also if one were just wanting to  upgrade the RSBASIC FP routines to IEEE 754 
standards, all one has to do is port the code in the MC6839 FP ROM fromOS9 to 
RSBASIC. That code is 8K.

james

On 2 Sep 2005 at 20:07, James Diffendaffer wrote:

To:             	ColorComputer at yahoogroups.com
From:           	"James Diffendaffer" <jdiffendaffer at yahoo.com>
Date sent:      	Fri, 02 Sep 2005 20:07:03 -0000
Copies to:      	Subject:        	[Coco] [Color Computer] Re: OS-9 as 
Replacement for DECB.
Send reply to:  	CoCoList for Color Computer Enthusiasts 
<coco at maltedmedia.com>
	<mailto:coco-
request at maltedmedia.com?subject=unsubscribe>
	<mailto:coco-
request at maltedmedia.com?subject=subscribe>

> The 68881 uses a different floating point format than the coco
> floating point.  A new Basic could be built around it and most
> software wouldn't be the wiser.  The only software that would have
> problems would be software that messes with the floating point numbers
> directly.  The 68881 would probably offer better precision.