[Coco] Are MC68B09E's and HM63C09E's as well as various support chips still available?

John Kent jekent at optusnet.com.au
Fri May 25 06:09:10 EDT 2012



On 25/05/2012 12:08 PM, John Kent wrote:
>
>
> On 25/05/2012 4:22 AM, jdaggett at gate.net wrote:
>> On 23 May 2012 at 23:47, Computer Doc wrote:
>>
>>> Has anyone recreated the 6809 or the 6309 in one of the FPGAs as a
>>> separate chip for inclusion in a breadboard design?  I'm glad to 
>>> have found
>>> others that are into the Coco 3 as much I was and am again.  Have a 
>>> great
>>> day and may God Richly Bless You all.  Thank you all in advance.
>> The 6809 as well as a complete Coco3 has been reproduced within both 
>> the XILINX and
>> ALtera FPGAs. As to this date I am unaware of anyone that has done a 
>> 6309 in an FPGA.
>>
>> james
> Hi James & Computer Doc,
>
> I am working on updating the FPGA 6809 design to include 6309 
> instructions.
> I have bursts of enthusiasm from time to time and then I'm distracted 
> by other things.
> As I mentioned on the list before, I have a 6809 SoC on the XESS XuLA 
> board, which is a 200K gate FPGA.
> It includes the CPU, PS/2 keyboard interface, serial port & text VDU 
> as well as a monitor ROM.
> It has 1MB of RAM with Dynamic Address Translation.
> It's a very tight fit in the FPGA. I'm not sure the 6309 design would 
> fit.
>
> I might write later. I have had a friend call in.
>
> John.
>

I had to go visit a friend. I'm back now. When I post stuff the list it 
seems to go quiet, so, I'm not sure how my posts are regarded.

I've ported my 6809 system to a number of FPGA boards. I've included the 
peripherals in the design, because the clock is 25MHz which is way too 
fast for the standard Motorola peripherals. There is not much point 
having a fast FPGA CPU unless you have fast peripherals and memory to suit.

I have a number of the peripherals such as ACIAs, PIAs, Timers and so on 
written in VHDL. The design is a pattern that can be replicated or 
instantiated as may times as you like provided there are enough pins on 
the FPGA to connect to connect all the I/O and there is enough FPGA 
logic to implement them all.

You don't have to lay out circuit boards. You can buy development boards 
that have the physical interface chips and connectors already on them 
and many of them have external expansion buses. If you like the fun of 
actually laying out a PCB, and you like the idea of having the physical 
chips in hand, then by all means design a PCB, or design an add on on 
board for an existing FPGA development board to implement features it 
doesn't have.

Having a potted design doesn't teach you much, but you can add your own 
peripherals, like a better video controller, sound synthesizer or data 
acquisition. There is a whole heap of things you can do with FPGAs. 
there was a Moog synthesizer on the Google search page the other day. 
You can implement digitally controlled oscillators rather than voltage 
controlled. Have Direct Digital Synthesis with a phase accumulator with 
programmable increment value, connected to a wave table in memory and 
have the wave table value output to an audio codec or DAC.

John.


-- 
http://www.johnkent.com.au
http://members.optusnet.com.au/jekent




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