[Coco] Kip's Single Board Computer
Dave Philipsen
dave at davebiz.com
Sat Sep 19 01:08:19 EDT 2015
Kip, would you rather build one from scratch or just get one already
built? I have a number of them already built that I could send out.
I'll try to write up a little documentation for it. I also have an
assembler and a monitor for it. For some things it can be faster than a
6809 because of the 4MHz speed but of course it won't do relocatable
code. If you're familiar with 6809 assembler code this will be a cinch
to pick up. Some mnemonics are a little different but more ways similar
than not.
Dave
P.S. I got the Moxham board in the mail yesterday and ordered the FPGA
dev board for it. Looks pretty interesting!
On 2015-09-18 23:47, Kip Koon wrote:
> Hi Dave,
> I would very much like to experiment with your HC11 PCB. It looks
> very interesting. I'm currently reading a book called Microcontroller
> Technology - 68HC11 & 68HC12. It would be interesting to play with
> this board as I learn the 68HC11. I have several HC11F1 chips on hand
> I could use. Please let me know everything I need to get this PCB
> going. Thanks a bunch in advance!
>
> Kip Koon
> computerdoc at sc.rr.com
> http://www.cocopedia.com/wiki/index.php/Kip_Koon
>
>
>> -----Original Message-----
>> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Dave
>> Philipsen
>> Sent: Tuesday, September 15, 2015 2:00 PM
>> To: CoCoList for Color Computer Enthusiasts
>> Subject: Re: [Coco] Kip's Single Board Computer
>>
>> Yep, it probably will. The beauty of the 'reset' chip is that it
>> continuously monitors VCC for an out-of-range value and will put the
>> CPU
>> back in reset if it finds that. A lot of times what causes a CPU to
>> 'lock up' is some dirty supply voltage that cause the something
>> abnormal to show up on the data/address lines and then the CPU takes a
>> hike to la-la land. This chip is like a power supply watchdog.
>> It also conditions a reset button input because, as you probably know,
>> mechanical switches can be noisy/bouncy.
>>
>> Here's a photo of a more recent revision of the board that I did with
>> onboard 5v regulator and a power supply barrel connector. The
>> 'HC11 runs at 4 MHz bus speed, has full 16-bit external address bus,
>> buffered data lines, some decoded chip selects, internal 1K SRAM,
>> internal 512-byte EEPROM, serial port, SPI port. The board has all of
>> the signals brought out to expansion connectors, the reset chip,
>> a 16 MHz oscillator, RS232 port, power LED. socket for RTC and
>> external EEPROM,
>> 27C256 EPROM socket, etc. If anyone's interested in playing around
>> with one or building it from scratch I could make up some
>> documentation for it along with a basic monitor in EPROM. I think I
>> still have quite a few bare boards floating around that I would sell
>> for cheap. And, it's a tried and tested design. As I said, I produce
>> somewhere in the neighborhood of 1,000-1,500 of these and they're
>> all still running now.
>>
>> http://www.davebiz.com/HC11-new.jpg
>>
>> Dave Philipsen
>>
>>
>>
>> On , John W. Linville wrote:
>> > Well, that seems fine. But I think a simple capacitor will do the
>> > job... :-)
>> >
>> > John
>> >
>> > On Tue, Sep 15, 2015 at 12:34:59PM -0500, Dave Philipsen wrote:
>> >> So I just sent Jim an offer to send a couple of DS1233-10 chips. The
>> >> chip basically holds a CPU in reset for 350ms after the power supply
>> >> comes up and is stable. I have used probably 1,500-2,000 of these
>> >> over the years in a little 68HC11 board I designed about 20 years
>> >> ago:
>> >>
>> >> http://www.davebiz.com/HC11.jpg
>> >>
>> >> You can see the DS1233-10 in the upper left corner of the board next
>> >> to the oscillator chip.
>> >>
>> >> Dave
>> >>
>> >>
>> >> On , John W. Linville wrote:
>> >> >On Tue, Sep 15, 2015 at 12:06:04PM -0500, RETRO Innovations wrote:
>> >> >>On 9/15/2015 11:49 AM, John W. Linville wrote:
>> >> >>>On Tue, Sep 15, 2015 at 12:15:15PM -0400, RETRO Innovations wrote:
>> >> >>>> The new board, as it were (it's getting less new by the month) is Kip's
>> >> >>>> take on Searle's 6 IC 6809. His is 8, and offers some interesting
>> >> >>>> enhancement options.
>> >> >>>>
>> >> >>>> But, when I try to bring the board up, I'm struggling:
>> >> >>>>
>> >> >>>> * there is no signal on Q or E.
>> >> >>>> * Nothing of interest on the crystal pins (though my Tek could be
>> >> >>>> interfering with the feedback).
>> >> >>>> * I took the CPU off the board, breadboarded with HALT and RESET
>> >> >>>> high, crystal and caps installed, and still no Q or E. I tried a
>> >> >>>> known working 6809 from my SuperPET, and nothing.
>> >> >>>>
>> >> >>>> I'm new to 6809/6309, so I am not sure where to start. I am sure once
>> >> >>>> I get the CPU running, the rest will be quick work, but the fact that I
>> >> >>>> can't seem to get a 6809 by itself to generate Q and E bothers me and
>> >> >>>> lowers my confidence that the board is ready to be debugged.
>> >> >>>>
>> >> >>>> Kip, send the man a board. I'll buy it for him.
>> >> >>>>
>> >> >>>> Jim
>> >> >>>I'm fairly certain that the clock problem is caused by the lack of
>> >> >>>RC circuit on the RESET^ line, as I described in my earlier
>> >> >>>note...do I get a board too? :-)
>> >> >>>
>> >> >>>John
>> >> >>Happy to buy you one. My time is precious, and saving 2-3 hours on
>> >> >>the bench is worth quite a bit at this stage in my life.
>> >> >>
>> >> >>So, for the 6809 noob, is there a data sheet page I should
>> >> >>reference for the correct cap/resistor values?
>> >> >
>> >> >So, the RESET^ reference on page 6 points to Figure 7 (which is on
>> >> >page 8). There it refers to the initial low time as "tRC".
>> >> >
>> >> >Near the bottom of the chart in Figure 1 (on page 3) it shows a
>> >> >maximum value for tRC as 100mS. Oddly, no minimum is listed.
>> >> >
>> >> >Referring to the Simon6809 schematic, it looks like he is using an R
>> >> >of 10Kohm and a C of 10uF. That should put you right at that 100mS
>> >> >"maximum", but it works fine.
>> >> >
>> >> >Anyway, I would suggest something approaching 100mS. Since Kip
>> >> >seems to have a 2.2Kohm pull-up on RESET^, maybe a 47uF capacitor
>> >> >from there to ground? Of course, that ignores the R10 and LED
>> >> >path...you may have to try some different cap values if that doesn't work...
>> >> >
>> >> >>I remember the reset controller from my 68hc11 days. Man, Motorola
>> >> >>was picky on reset.
>> >> >
>> >> >:-)
>> >> >
>> >> >John
>> >> >--
>> >> >John W. Linville Someday the world will need a hero, and you
>> >> >linville at tuxdriver.com might be all we have. Be ready.
>> >>
>> >> --
>> >> Coco mailing list
>> >> Coco at maltedmedia.com
>> >> https://pairlist5.pair.net/mailman/listinfo/coco
>> >
>> > --
>> > John W. Linville Someday the world will need a hero, and you
>> > linville at tuxdriver.com might be all we have. Be ready.
>>
>> --
>> Coco mailing list
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