[Coco] Re: Coco Repack

[David Gacke]

It's funny that all this talk about new CPUs and GIMEs got started. I've
been working on a new CPU of sorts for the CoCo in my limited spare
time.

I've taken a Microchip dsPIC microcontroller and wired it into the 6809
socket.

I've got the thing all wired up and communicating properly through the
6809 CPU socket and am working on subroutines for the opcodes
themselves.

This was the reason for my 0xABCD endian questions the other night.

As far as I can tell, I should be able to complete all 6809 instructions
in 1 clock cycle after being loaded, plus throw in some new opcodes for
MMX-like functionality.

Anyway, it's kind of a pet project currently.

If anyone wants to see pics sometime, just drop me a note, I'll try to
throw them up on my website.


Dave Gacke


-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com]
On Behalf Of jdaggett at gate.net
Sent: Friday, August 06, 2004 8:45 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Re: Coco Repack

Frank

The 6809E and 6309E are pure digital curcuits. The limiting factor 
for speed is load capacitance for various logic gates. 

True the CMOS parts as well as the Motorola NMOS parts are 
limited to not much more than 4 to 5 MHz. The 6809 might squeeze 
out a bit more if you raise the VCC up to 6 to 6.5 VDC and heat sink 
the chip. The biggest concern is switching speeds is to get the heat 
off the die. The injection molded plastic packages do not do as good 
a job as the older ceramic packages did. 

Overall I do agree that around 6 to 8 MHz is the ultimate limit.

james

  
On 6 Aug 2004 at 22:45, farna at att.net wrote:

From:           	farna at att.net
To:             	coco at maltedmedia.com
Date sent:      	Fri, 06 Aug 2004 22:45:25 +0000
Subject:        	[Coco] Re: Coco Repack
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>

> IIIRC the 6309 is a 4 MHz part? I doubt it will run reliably after 6-8
> MHz. Even then, it could vary between chips. If you put a 6309 in FPGA
> you could drop some of the 6809 compatibility and possibly put in some
> new code, but then you'd lose program compatibility. Not sure how much
> that would affect NitrOS9 for the 6309 though. Still, if you do a CoCo
> repack with the joystick ports and replace the bit banger with USB (or
> two...), it would be a nice system. Wouldn't be 100% CoCo compatible
> once the ROMs were in place, but would be close. Would be very nice if
> the DECB ROM could be modified to use a USB floppy, and maybe HD. But
> DECB really doesn't need a HD for experimental purposes. Some sort of
> mass storage would be needed, maybe one of those USB "drives" would be
> easier to code in the ROM, but you'd have to transfer code from a PC
> to run DECB programs. The only reason I harp on DECB is the ease of
> programming for experiments. Basic09 is more powerful, it has
> similarities t
>  o Pascal, but CoCo BASIC is so darned easy to learn that for simple
>  and/or quick experiments it would be preferred. 
> 
> 
> --
> Frank Swygert 
> Publisher, "American Independent 
> Magazine" (AIM) 
> *Elite* publication for those 
> interested in all 
> aspects of AMC 
> history,performance,restoration,etc 
> . 
> (AMC,Rambler,Nash,Hudson,Jeep,etc.) 
> http:farna.home.att.net/AIM.html 
> (free download available!) 
> 
> 
> 
> -------------- Original message from coco-request at maltedmedia.com:
> -------------- 
> 
> > Message: 3 
> > Date: Fri, 06 Aug 2004 11:30:48 -0400 
> > From: jdaggett at gate.net 
> > Subject: Re: [Coco] Re: Coco Repack 
> > To: CoCoList for Color Computer Enthusiasts 
> > Message-ID: <41136BE8.14904.E66F7 at localhost> 
> > Content-Type: text/plain; charset=US-ASCII 
> > 
> > Frank 
> > 
> > You are ringt if a FPGA version of the 6x09 were incorporated 
> > along with an FPGA version of the GIME chip, breaking the 10 MHz
> > barrier will be no problem. Speed control can be done with external
> > clock ship. One by ICT can derive 1000's of frequencies from a
> > single crystal frequency. In fact the one chip that I was looking
> > at, from a 28.6868 MHz cyrstal I can derive over a 1000 different E
> > and Q Clocks for the CPU from 400 KHz to 19 MHz. 
> > 
> > My initial intent was to use a 6309 and my new GIME chip and j ust
> > see how fast I can over clock the 6309. I have two bytes resevered
> > in the memory map to address the clock PLL chip. 
> > 
> > Just keep pushing the clock until the chip stops. 
> > 
> > james 
> 
> -- 
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco



-- 
Coco mailing list
Coco at maltedmedia.com
http://five.pairlist.net/mailman/listinfo/coco