[Coco] Re: Any reason to put a 6309 in a Coco2?

[jdaggett at gate.net]

On 31 Dec 2003 at 16:14, Alex wrote:

>The 6309 was supposed to simply be
> a CMOS version of the 6809.  All of the extra 6309 stuff was secretly
> put in by the engineers on the project.  Officially Hitachi knows
> nothing about there being any functional differences.  AFAIK that this
> is what was put out when talk about the 6309 first broke out on the
> CoCo list.
> 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco

My first impression is to say that this is a bovine pile. But .....

First by the mid 80's HMOS was a mature process and CMOS for processors was 
not a viable process for home computers as they were just to slow. Now if the 6309 
was destined for embedded designs then I could see that. Still CMOS was slow. The 
MC146805E2 was already old hat by 1983. It had already been in use for two years. 
By the mid 80's the HCMOS process had surpassed standard CMOS. Motorola in 
1983 did an advance announcement that they were intending to move the 
MC6809E from HMOS to HCMOS process. That never happened. Why I am not 
sure. Most likely due to the fast growth in the 68000 and that they ended up moving 
the 68000 over to an HC process. Furthermore the 6805 line went form HMOS to 
HCMOS. The 6809 just lost out. 

Hitachi licensed the instruction set from Motorola in the mid 80's. Also the license 
was extended to TI and ST Micro. TI never really got into a large production nor did 
ST. By 1989/1990 Motorola announced the cancellation of the MC6809 line.

Hitachi in my opinon would not put circuitry on a die unless they intended to use it. 
Believe me real estate on a die is precisous and expensive. No one in the industry 
puts circuits on a die to just put them on. If my memory serves me correct I think 
that the number 8 in the orient is not one of the lucky numbers. I vaguely remember 
that the number 4 is real unlucky.

Hitachi did manufacture and label an HD68x09/E. My guess is that they intended to 
circumvent Motorola's license and patents and told Motorola that the 8 was unlucky 
and that the licensed parts of the MC/HD68x09/E would be labeled as HD63x09/E 
for the orient market only. The 6309 was never intended to be shipped into the US 
market. That way they could market a superior processor and hoped to get around 
license agreeements and any ptent violations.  

All this became mute by the end of the 80's. Intel had the 286 and the 386 was not 
far behind. Apple was using the 68000/68010/68020. The 8 bit market for home 
computers was over. It was relagated to game and embeded systems. The HC11 
and HC05 was fast becoming a favorite of the embeded market and the 6809 and 
6309 were becoming dinosaurs. Hitachi learnt a lot from the license 
agreement.They have been a competitor to Motorola in the 8 bit market with their 
H8 line of processors as well as the 16 bit market. 

just some of my thoughts

james