[Coco] Kip's Single Board Computer

Sat Sep 19 00:47:14 EDT 2015

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.
> >>
> >> --
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> >> 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.
> 
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