[Coco] 6809EP - Worth it?

[jdaggett at gate.net]

On 19 Jan 2010 at 1:18, Mike Pepe wrote:

> > -----Original Message-----
> > From: coco-bounces at maltedmedia.com [mailto:coco-
> > bounces at maltedmedia.com] On Behalf Of J.P. Samson
> > Sent: Monday, January 18, 2010 5:08 PM
> > To: CoCoList for Color Computer Enthusiasts
> > Subject: Re: [Coco] 6809EP - Worth it?
> > 
> > On Jan. 18, 2010, at 5:51 PM, Andrew wrote:
> > > I was browsing around a favorite local electronics surplus haunt of
> > > mine, and found that they had a cache of MC6809EP processors, in
> > > tubes of 5 or 6. The condition of the parts looked NOS; but other
> > > than that, unknown.
> > 
> > I believe the CoCo used a 68B09E.  That 'B' indicates that it can
> > operate at speeds up to 2 MHz.  A 68A09 runs at 1.5 MHz.  A plain 6809
> > maxes out at 1 MHz.  I think the 'EP' refers to requiring an
> > 'e'xternal clock and that it uses a 'p'lastic package.  So my concern
> > is that these chips you have found could not operate in the CoCo at
> > the speed required.
> > 
> > -- JP
> > 
> 
> They will likely work fine at 2MHz, but 68B09E chips are neither rare nor hard to find; Jameco has them for $8 a piece. $6 sounds like a reasonable price per unit for a 6809E.
> 

Back about 6 or 7yrs ago there was a flood of MC68x09Es that hit EBAY for several years. 
here are still some that sell the MC6809 on there but way over priced frommy point of view. 
Some of them are in the old ceramic package. I still think some want way to much for them. 
Every now and then you see a Hitachi version of the (HD)68x09E. Now rare is the HD63x09E 
parts. 

I know of at least four mask sets for the 68x09E chip. There are at the least five or six mask 
sets for the MC68x09 (internal clock). The later mask sets and date codes are capable of 
running at least 1.5 times rated speed. This probably due to a die shrink and wafer size 
change. I have first hand experience of the MC68B09s running at bus rate of 3 MHz with very 
little issues. 

I have some MC68B09E with date codes of 9842. That is week 42 of 1998. These are some 
of the last production parts Motorola ran before shutting down the line completely and 
shipping the mask sets to Rochester Electronics for archive. 

james