[Coco] MC6809 Inards

[jdaggett at gate.net]

On 4 Oct 2006 at 22:27, L. Curtis Boyle wrote:

> Wasn't the GIME by VLSI? Also, there isn't anything about the hidden modes
>  on Hitachi's 6309 chip, is there? I assume not, since the extra features 
> were not supposed to be public knowledge.

*************

Curtis

I have not searched for the 6309 or Hitachi, but after looking at some patents # of 
registers and instruction set does not seem to be all that patentable. Added 
circuitry to solve a problem that some other invention is patentable. There may 
have been lincensing agreements that would be violated had all the true workings 
of the HD6309 came out in the late 80's.  My guess is that Hitachi wa lincense to 
do a CMOS version  of the  MC6809 an dnot a redesign. 

I have both the 1986 and 1987 GIME chips and the 1986 is labeled VTI. The 1987 
is VLSI.

james