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== Introduction ==
*First and foremost, I would like to express my gratitude and appreciation to [[Allen Huffman]] for extending an invitation to me to host my personal web page on his Cocopedia web server.
*I invite you to check back periodically as I document my experiments with my Coco 3 setup and my 6809/6309 microprocessor computer projects.
*Let's turn the time machine back to about 2011.  I had been looking for work for about three years.  One day I decided in addition to that, I would go back and explore my computer roots.  Now let's really turn the time machine way back to about 1982.
*In the early 1980s, my first computer was a TRS-80 Color Computer 1.  It had 16K of RAM on an F version motherboard that I later upgraded to 64K.  I did everything I could to find out information about that little machine.  The internet certainly did not exist back then.  It fascinated me and held my attention for hours on end.  The only printer I had at the time was an ASR-33 Teletype with paper tape reader and punch.  I don't remember whether I started out with Color Basic 1.0 or Extended Basic 1.0, but either way my primary storage medium was cassette based only.  Boy, that cassette machine was a challenge to work with!  :)
*Later on I eventually upgraded to a Color Computer II.  The keyboard layout on this machine was the same as before but it was a lot nicer and it came with 64K of RAM!  Somewhere along the way I started using 5.25" floppy drives and started experimenting with OS-9 LI v01.00.00 or 01 and for the first time I felt like I could really do something special with this machine. 
*Spinning the clock forward a little ways sees me purchasing my first Color Computer 3.  Whether the label was TRS-80 or Tandy, I don't remember.  All I knew is it had 128K of RAM!  Now I really had a great and mighty computer in my collection.  Also, at some point in time I eventually installed a Seagate Model Number ST-225 20MB MFM hard drive running OS-9 LII v02.00.01 on a Color Computer 3 with 128K of RAM with a Winchester 8-bit hard drive controller card from Burke and Burke.  
*Then the IBM PC revolution began and my computer interests migrated to building an 80286 based PC and I left the Color Computers behind forever, or so I thought.
*I have always wanted to build a 6809 microprocessor based computer of some sort for the express purpose of learning microprocessor interfacing with the best and my favorite microprocessor of all time.  I never had the opportunity nor the resources to build a SouthWest Technical Products Company computer back in the late 1970s as I was still in school until my graduation on June 4, 1978.  All through school, however, I drooled over all the computer magazines and computer programming books I could find.
*After high school graduation, I went to work with a close friend of mine who used a Motorola Exorciser running an MDOS operating system.  It booted up into a monitor program called ExBug.  To boot MDOS, the user first entered a one letter command with some sort of parameter and off it went booting MDOS off of an 8" floppy disk drive.  Those drives were huge!  The system had two drives and an 8-bit MC6800 Microprocessor ran the whole thing.  
*Ok, now we are up to about 2011 when I make my decision to build a 6809 microprocessor based computer.  I start scouring the internet looking for people who had built any type of 6809 computer or just even had written papers on the subject.  Eventually I collected several notebooks full of documentation about several dinky 6809 computer systems.
*Although I had been reading Motorola Data Books for decades, I had actually never built anything.  It all always seemed a bit out of my reach.  Well, I finally found a very simple 6809 microprocessor based computer that only used 6 chips and you could program it in Basic!  Amazingly enough, it turned out it ran a copy of Extended Color Basic from Radio Shack's old Color Computer line that I had used all those years ago.  All the graphics routines were removed since the only way to talk to it was to use some type of ASCII CRT terminal or terminal program running on a PC.

== My Version of Grant Searle's 6-Chip 6809 Computer ==
*Narrative about my experience designing and building my version of Grant Searle's 6-Chip 6809 Computer.  The link to his web site is http://searle.hostei.com/grant/6809/Simple6809.html
*I decided to use Grant's 6-chip 6809 Computer as the basis for my very first 6809 microprocessor based experimental computer.  It took me several weeks studying all the datasheets before I felt confident to wire up the 6-chip computer.  Initially, I built my 6-chip computer exactly like Grant's, then I added another 8K of RAM using a second 32KB cache RAM chip from an old PC motherboard.  When I fired it up for the first time, it passed the smoke time with flying colors, i.e. no smoke!  It did not however communicate with my Hyperterminal program I was running on my laptop.  I contacted my close friend and mentor and asked him several things about RS-232 communications and he told me that that was one of the hardest parts of a microprocessor circuit to get right.  Well, I finally got it to work and I was basically programming in Extended Basic.  In fact Grant Searle named his version of Radio Shacks Basic "6809 Extended Basic".  I was ecstatic and beside myself with joy!  It was Alive!  I had done it!  I had built my very own 6809 microprocessor based single board computer.
*I didn't take me long before I wanted to add an additional function to my computer.  Back to scouring the Internet I go looking for ideas.  I finally decided on adding an MC6821 Peripheral Interface Adapter along with an AY-3-8910 Programmable Sound Generator.  I wanted to hear my computer.  one problem lead to another problem and I finally had to scrap that idea and figure out why my RS-232 port was not working any more.  After investigating for awhile, I finally put it down to think.  I had been peeking and poking using the Basic interpreter to try to communication with the PIA and the PSG chips, but to no avail.  I put my computer down for awhile and fix some more PC desk tops and laptops for some customers for a little while.  There weren't that many.
'''April 9, 2013'''
[[File:My Version of Grant Searle's 6-Chip 6809 Computer with some extras Top View.jpg|1000px]]
* This is my version of Grant Searle's 6-Chip 6809 with some added extras.  
*The MC68B09P Microprocessor chip is bottom in left-most column. Above the 6809 is an AS7C256-15PC 8K x 8 bit (32KB) static ram (sram) chip addressed from $0000 to $7FFF.  
*Above the sram is a 27128 eprom programmed with Grant Searle's 6809 Extended Basic.  The 6809 Extended Basic is basically Radio Shack's (Tandy's) Extended Color Basic with all the graphics commands removed.  
*The top chip in the first column is a DM74LS00N Quad 2-Input NAND Gate chip which is used as part of the address decoding logic.  This is the only 74LSxx logic chip Grant used in his design.
*In order to add an additional 8KB of sram additional logic is required, so moving over to the second column of chips, the top chip is an SN74LS32N Quad 2-Input Positive OR Gates.  
*The second chip is an SW7404N Hex Inverter chip.
*The third chip is a W24257AK-15 8K x 8 bit (32KB) Static Ram chip of which only 8KB is used as the memory map does not allow anymore ram.  The extra address lines are grounded.
*The next item down is 7 header pins used to connect to an RS-232 cable.
*The next chip is a MAX232N Dual EIA-232 Drivers and Receivers chip to convert the serial TTL signal levels from/to the MC6850 ACIA chip to RS-232 signal level standards.
*The bottom chip in the second column is an MC6850 Asynchronous Communications Interface Adapter to enable the 6809 to communicate with the outside world via an RS-232 interface cable.  The MC6850 chip is addressed at $A000 to $BFFF.  The Address decoding logic is incomplete.  This is necessary to reduce the chip count in Grant Searle's original design to keep it at just 6 chips total.  I thought it was a fantastic design for first time builders to use.  My kudos go to Grant Searle for an excellent job well done.
*The first chip in the third column is a 74LS00PC Quad 2-Input NAND gate chip. The three additional logic chips I added to Grants design to enable me to add the additional 8KB of static ram. 
*At this point my project was complete with 40KB of Static ram.
*After initially testing my project without the extra 8KB of sram, I wanted to finish filling up the memory map as there was an 8KB hole at $8000 to $9FFF.  This hole in the memory map was hollering out to me for more ram, so I added it.  It was to be my very first logic circuit design.  I designed the logic required to add some static ram at $8000 to $9FFF.
*When I tested my design, it worked correctly the first time.  Now I have a total contiguous static ram memory from $0000 to $9FFF.
*The rest of the third column has the logic chips necessary to drive the 32 LEDs so I can see what is happening in real time on the sixteen address bus lines, the eight data bus lines and the eight control lines.
*The second chip in the third column is an SN74LS244N Octal Buffers and Line Drivers with 3-State outputs chip driving eight red LEDs which show the current state of address lines A15 to A8.
*The third chip down is another SN74LS244N Octal Buffers and Line Drivers with 3-State outputs chip driving eight yellow LEDs which show the current state of address lines A7 to A0.
*The fourth chip down on the third column is an SN74LS245N Bi-directional Octal Bus Transceivers with 3-State outputs chip driving eight green LEDs showing the current state of the eight Data bus lines.
*The fifth and last chip in this design has another SN74LS244N Octal Buffers and Line Drivers with 3-State outputs chip driving four green LEDS and four yellow LEDS showing the current state of eight control lines.
*The first pushbutton is the Reset pushbutton used to reset the 6809 microprocessor.
*The second pushbutton is the Halt pushbutton used to halt the 6809 microprocessor.

== My Version of Erturk Kocalar's SiMon6809 Computer ==
*Narrative about my experience designing and building my version of Erturk Kocalar's SiMon6809.  The link to his web site is http://www.8bitforce.com/simon6809/.
*I surf and surf the internet sometimes out of sheer boredom and what do I find, but Erturk Kocalar's SiMon6809 single board computer.  I think on this awhile studying the monitor program that runs on it when I see that the monitor program allows the user to enter assembler code straight into memory!  No hex bytes to fool with!  I loved this.  I read on and it even lists the memory back to the user as in an assembler listing!  Well, this is just too cool.  Wouldn't have all the computer engineers from the 1970s and 1980s loved to have had a monitor like this one and running on my favorite microprocessor too!
*That does it!  I have to build this 8-bit 6809 based computer also!  Over the next few nights I finally decide on a chip layout on my solderless breadboard and press in all the chips.  In one night I end up wiring almost the entire computer.  After all it is only 9 chips plus a USB prototype module.  My first 6809 computer had 14 chips and 32 LEDs on just about every signal in that computer.  I had added the 32 LEDs so I could see if the computer was doing anything.  The 6809 microprocessor was functioning just fine.  I just could not see anything in HyperTerminal.
*I had to take care of another customer's laptop so I had to put down my SiMon6809 computer for a few days.  During this time, I get an offer from a friend, [[Allen Huffman]] to host a personal web page on his server. Thank you Allen.
*It is now April 6, 2013, its 11:43 pm and I'm plugging away entering my 6809 single board computer experiments' experiences on a brand new web page!  Isn't life great!  
*I finally have a picture for my version of Erturk's SiMon6809 computer and here it is.
[[File:My Version of SiMon6809 Top View.jpg|1000px]]
*My version of Erturk Kocalar's SiMon6809 computer mounted on another solderless breadboard.  
*An interesting note about this particular breadboard.  I had originally built an MC6802 Microprocessor & MC6846 Rom, I/O & Timer chip based computer with MikBug programmed into the MC6846's rom, but the chips had been sitting in black antistatic foam for so long (since about the 1980-1981 time frame) that it stuck to the pins so badly that even scraping with a fairly good-sized pocket knife blade could not get it all off the pins.  I was sadden by the fact that I could not complete this project, so I put it away for awhile thinking I would get back to it some day.
*Well, some day has arrived, but instead of completing my 6802 based computer with a monitor program, I scrapped the entire design put together with telephone wire in favor of a 6809 based computer with a monitor in rom using proper 22 gauge hookup wire instead of the 28 gauge telephone wire.  The telephone wire did not stay in the breadboard holes very well anyway.
*Now back to describing this breadboard layout.
*I decided this time to start in the top left corner to mount the MC68B09P microprocessor chip instead of the bottom left corner of the breadboard.
* The second chip is a 27128 16KB eprom programmed with Erturk's monitor program that somehow got called Buggy 1.0.  I'd like to hear the story about how the name Buggy came to be.  I bet it is an interesting one.  There is a long story about the monitor program itself.  Erturk actually did not create it.  He just modified it to work with the USB FT245R USB chip.  In his design, he uses the chip itself, but since I was prototyping my design on breadboard, I needed the chip in a through hole design.  I look for a through hole version on FTDI's web site and came across the USB Prototype module which takes the FT245R surface mounted design and puts in onto a little PCB barely the size of a 24 pin chip suitable for breadboarding.  Thank you FTDI for this module.
*The third chip in this column is an MT5C1008-35 128KB Static Ram chip configured as 64KB.  I'm not yet including any type of Memory Management unit, so I grounded address line A16, thus I have 64KB and not 128KB.  Ah, but you say there is not room for the eprom? This is where I start blazing new trails in my young computer electronics designing portion of my life.  This is where my design starts to stray from Erturk's Design.
*I am using three SN74LS138N 3-line to 8-line decoder/demultiplexor chips in an address decoding scheme to give me a plethora of addressing choices to put the future additions and features not yet conceived of and yet to be designed for this project.
*The second column first item is a pushbutton for the reset line to reset the 6809 microprocessor.
*The second item is the first of three SN74LS138N 3-line to 8-line decoder/demultiplexor chips to decode the top 4 address lines A15 to A12 to give me eight possible choices.  Each output decodes a 4KB area.  They are of course, $8xxx, $9xxx, $Axxx, $Bxxx, $Cxxx, $Dxxx, $Exxx, $Fxxx.  I pick the $Dxxx output line and feed it into the next SN74LS138N 3-line to 8-line decoder chip.
*The third item is another SN74LS138N 3-line to 8-line decoder/demultiplexor chip configured to further decode address lines A11 to A8 down to again another eight possible choices.  With the output of $Dxxx from the previous SN74LS138N chip, the eight possible choices are $D8xx, $D9xx, $DAxx, $DBxx, $DCxx, $DDxx, $DExx, $DFxx.  The $DFxx output is fed into the DM74154N 4-line to 16-line decoder chip.
*The fourth item in the second column is the third SN74LS138N 3-line to 8-line decoder/demultiplexor chip to decode address lines A15 to A13 to arrive at yet another eight choices this time to be used for the Eprom chip.  These choices are $0000 to $1FFF, $2000 to $3FFF, $4000 to $5FFF, $6000 to $7FFF, $8000 to $9FFF, $A000 to $BFFF, $C000 to $DFFF, and finally $E000 to $FFFF.  The $E000 to $FFFF output is feed to the Chip Enable pin of the 27128 16KB Eprom chip.  It is also inverted and fed to the chip enable pin of the static ram chip.  They way, the eprom or the sram are accessed exclusive of each other.  The two are never enabled at the same time.
*The Fifth item is an SN74LS139AN 2-Line to 4-Line decoder/demultiplexor chip to provide the read and write signals to the UM245R USB Prototype module at the proper address.
*The sixth and last item in the second column is a second SN74LS139AN 2-Line to 4-Line decoder/demultiplexor chip to provide the proper read and write signals to the 128KB Static Ram chip and the 27128 16KB Eprom chip.
*The Third column at the very top is a DM74154N 4-Line to 16-line decoder chip to decode the addess lines A7 to A4 to arrive at the third and final stage of the I/O block addressing.  The final sixteen choices are $DF0x, $DF1x, $DF2x, $DF3x, $DF4x, $DF5x, $DF6x, $DF7x, $DF8x, $DF9x, $DFAx, $DFBx, $DFCx, $DFDx, $DFEx, and $DFFx.  The $DF0x output line is fed to the first SN74LS139AN chip to address the UM245R USB module at $DF00 to $DF0F.  I have narrowed a 4KB block of addresses down to sixteen addresses.
*The second chip in the third column is a Dallas DS1287 Real Time Clock chip so my 6809 computer will know what time it is.  It is not connected up and won't be until the original design is tested and fully functional.  Then I will add this chip into the memory map and start playing with it.
*And last but certainly not least is the UM245R USB Prototyping Module from FTDI and was if I remember correctly about $25.  It's a little expensive, but then I did not have to design and build it.  This saves me a lot of time.  This chip is addressed at $DF00 to $DF0F.  I'll have to check the program and documents on the module to be sure, but it takes up only one memory location, so in sixteen bytes I can have, well, 16 USB ports if I so choose.  Of course, at this point what would I do with sixteen USB ports.  This is a slave USB port, and we would need some master USB ports if I am going to plug up some USB devices to my 6809 computer.  I don't know yet how many memory locations one of those modules takes up, so I will leave the rest of these bytes undefined and unimplemented which means the UM245R module will appear sixteen times in the memory map instead of 4096 times or 4K as is in Erturk's original design.  Again, Erturk did minimal address decoding to reduce chip count in his SiMon6809 computer to keep it small.
*The USB prototype module in this design is addressed at $DF0x and the FT245R chip in Erturk's original design of SiMon6809 is addressed at $Dxxx.  Again this is done to reduce chip count in Erturk's design, but I wanted to further decode the addressing down much further.  I wanted to lay the ground work for moving the address decoding for the block of I/O for all communications devices and chips eventually to the $FFxx range.  Since you are reading the Cocopedia.com web site, I bet you can guess want I'm leading up to, but for those that are still learning, I won't spoil the surprise yet.
*It's April 9, 2013 and this completes the initial description of my version of Erturk Kocalar's SiMon6809 computer that I've built thus far.  I have many plans for this 6809 computer, so stay tuned for further updates to this web page.  
*Remember in the beginning I told you I was not able to build an SWTPC 6800 or 6809 computer back in the 1970s and 1980s nor was I able to build an Altair 8800 or IMSAI, and I wanted to experience the thrill of building my own 6809 computer from scratch using proven designs and methods to reduce drastically the trial and errors stage of design.  Of course my changes to the original designs will have to be tested.  For example, I changed the address location for the USB port.  In Erturk's original design, it was located at $D000 in the assembler code for the monitor program.  In my project, I set it at $DF00, so I will need to reassemble the monitor program with the new USB port address which is really no problem.  I could have left it at $D000 with it replicated 4096 times in the memory map, but I wanted a more versatile design, so I won't be seeing my USB port at $D000, but at #DF00.
*Stay tuned for further updates. :) This is going to get interesting as I get the basics out of the way and start seeing this thing come to life!

== My Coco 3 Setup ==
'''April 4, 2013'''
*Fired up my new Coco 3 for the first time and gazed upon the standard Extended Color Basic copyright message.  There it was in living color, my Coco 3 is alive!
'''April 5, 2013'''
*After having burnt an eprom with the "HDB-DOS v1.4 DW4 Coco 3" rom image a few weeks back, I install it into my Disto Super Controller. Once I had closed up the super controller, I inserted the cartridge into the Coco 3's cartridge slot and powered up the Coco 3.  Behold, my eyes peered on the screen to see the Disk Extended Color Basic copyright message and below it was displayed the HDB-DOS V1.4 DW4 COCO 3 message and the OK prompt appeared with the famous flashing color cycling curser.  I did not get any floppy drives out of storage yet, so my test ended here.
[[File:HDB-DOS_v1.4_DW4_Coco_3_Boot_Screen.jpg|500px]]

'''April 6, 2013'''
*The next day saw me looking through all my computer stuff in storage for 3.5" floppy drives.  I found a number of them with selectable device select jumpers, so I started a stack of them.  I ended up with eight 3.5" drives with changeable drive select jumpers.  I took three of them into the house and commenced to connecting up two of the drives.
*I Connected up two 3.5" floppy drives to the Disto Super Controller and formatted a 720KB floppy disk and a 1.44MB floppy disk with the Double-density/High density hole covered up to make the floppy drive think it is a 720KB floppy.  Both types of floppies formatted perfectly. I wrote a very simple basic program to read all memory locations from $8000 to $FFFF and display them as characters on the screen.  I then saved the program to one of my freshly formatted floppies and typed the command NEW.  Now that the basic program is not in memory anymore, I read the program off the floppy and load it into the computer's RAM memory.  Then I ran the program and all the bytes stored in the eprom were being displayed as text and graphic characters. It worked perfectly!
'''April 7, 2013'''
*I booted VCC on an old Windows XP desktop mini-tower computer with the special fdrawcmd.sys driver installed to enable the system to create coco compatible floppies.  I loaded "NitrOS-9 6309 l2 v3.2.9 coco3 80 trk" image into virtual drive 0.  I entered the infamous DOS command to boot into NitrOS-9.  The white screen appeared and garbage characters filled the screen.  I said, "What?".  It took me a while to realize my coco 3 is still using an MC68B09EP microprocessor chip. Ah ha!  I needed the 6809 boot image.  I had been using the 6309 version of the boot image for so long in VCC, that I had completely forgotten that my real coco was still running the original Motorola microprocessor.  
'''April 8, 2013'''
*I go back to my desktop computer, boot up VCC again this time using the "NitrOS-9 6809 l2 v3.2.9 coco3 80 trk" image in virtual drive 0.  I DMODEd drive /d1 changing the cylinders from 35 tracks to 80 tracks with the command "dmode /d1 cyl=50".  The cylinder parameter is in hexadecimal - $50 = 80 decimal.  
*Then I issue the "format /d1" command, check the floppy disk parameters to make sure they are what I need and answer "Y"(es) to the "Ready" prompt and away it goes formatting a real 3.5" 720KB floppy using a virtual Coco 3.  Thanks guys for creating VCC.  I love it.  
*Once the floppy is formatted, I issue the "backup /d0 /d1" command to backup the NitrOS-9 virtual disk image I booted VCC with to arrive at a real bootable NitrOS-9 floppy disk to use in my real Coco 3.
*Now I go back to my real Coco 3 setup in the living room and I inserted the 6809 version of the NitrOS-9 boot disk into the coco 3's floppy drive, enter the DOS command and behold, NitrOS-9 started booting!  :)  I love it!  My favorite disk operating system is finally booting on my real Coco 3!
[[File:NitrOS-9_Booting_Modules.jpg|600px]]
[[File:NitrOS-9_Booted_Default_Screen.jpg|600px]]

*As you can see, the composite video output of the Coco 3 in my setup makes the NitrOS-9 screens almost completely unreadable.  Except for the fact that I already know what is on the screen from seeing it in VCC, I would have no idea what is there.
*So I issue a shell command to create a new window hoping I can see little better what the text on the screen actually is with the command "shell i=/W7&".
[[File:NitrOS-9_with_a_newly_shelled_screen.jpg|600px]]

*Now it is time to test some more 3.5" floppy drives.
*The procedure I use to test a floppy drive is to boot NitrOS-9 and change the cylinders on drive /d1 to $50 and format a floppy disk.  If the format is a success, then I backup my boot disk from /d0 to /d1. Then I remove all disks and power cycle the computer.  I put the newly made boot disk into drive /d0 and see if NitrOS-9 boots successfully.  If the boot finishes with flying colors, I call the floppy drive good.
*Using this procedure, I end up with three good 3.5" floppy drives out of the original eight floppy drives I found with changeable drive select jumpers.  During the testing, however, I found a couple of Chinon Model FZ-357 floppy drives with 14 jumper pins giving 9 possible jumper settings that when set to be drive 2 and one at a time are accessed, Drive 0 also is accessed at the same time.  They however run fine when set to be drive one.  So although I have the cabling to run three 3.5" floppy drives, I effectively can only run two.
*Now here's the kicker.  Back in the day I ended up buying several floppy disk controllers.  They are, in no particular order, the Disto Super Controller, a Hard Disk Specialist Color Computer Comtroller, a J&M Systems Floppy disk Controller, and the  Burke & Burke XT Interface adapter with a Winchester 8-bit ISA card running an MFM 20MB hard drive.
*Now, except for the Hard drive controller for obvious reasons, all the others will drive up to three floppy drives.  Well, and this is the interesting part, I was able to get one of them to drive two DSDD 40Trk 5.25" floppy drives and two DSDD 80Trk 5.25" floppy drives.  You ask how did I do that?  If I remember correctly, in the documentation for the Disto Super Controller, Tony brought out all the signals being controlled correctly somehow making the controller able to support four DSDD drives.  I going from 30+ year old memory here, so I'll need to find that documentation to verify this, but I strongly remember this being true.  I have an old DEC Dual Full Height 5.25" floppy drive case I had bought from a HAM FEST decades ago with two full height flopyy drives in it that I pulled out and replaced with two 40 track DSDD half height floppy drives and two 80 track DSHD half height floppy drives so I could take advantage of this very feature.  At one time in my twenties, I had four half height 5.25" floppy drives running on my Coco 2.  Now to figure out how I did it and do it again.  There will definitely be more to come on this later. 
'''April 9, 2013'''
[[File:Entire coco 3 setup for testing.jpg|caption|1000px]]
*This is my Coco 3 testing setup in the living room to first get everything going.

== Biography ==
My professional biography will go here.
== Resume of Kip Koon ==
*Professional inquiries may be sent to me via email to:
**c o m p u t e r d o c at s c dot r r dot com
== Miscellaneous ==
*All suggestions for 6809 and 6309 microprocessor based projects are welcome.  Please keep them both positive and helpful.  
*Thank you for visiting my little corner of the Wonderful World of the Coco 1, 2, 3, the 6809 and 6309 microprocessors.  
*Qaplah! Shalom! Keep Having Fun!
--[[User:Computerdoc|Computerdoc]] ([[User talk:Computerdoc|talk]]) 21:09, 6 April 2013 (CDT)The Computer Doc