[Coco] FW: My 6809 Computer is Working!

[johnchasteen at juno.com]

On Thu, 26 Jul 2012 22:06:24 -0400 "Kip Koon" <computerdoc at sc.rr.com>
writes:

> Thanks guys.  Your very kind words mean quite a bit coming from 

> fellow 8-bit

> Microprocessor enthusiasts like yourselves, especially when you've 

> published

> your work on the internet.  I'm looking forward to seeing what 

> fascinating

> microcomputer designs you guys come up with next. I pray blessings 

> on all

> your efforts.

> 

> Kip

> 

> From: Paulo Lindoso

> Sent: Thursday, July 26, 2012 8:37 AM

> Subject: Re: [Coco] FW: My 6809 Computer is Working!

> 

> Absolutely!

> 

> These days i get happy just to spare 10 minutes to READ the list... 

> ! (and

> post an odd useless remark ;) )

> 

> Cheers

> Em 26/07/2012 03:17, "Erturk Kocalar" <erturkk at kocalar.com> 

> escreveu:

> 

> > Hi Kip,

> >

> > I envy you soo much.  You can find time to work on fun projects 

> and 

> > keep us upto date.  Keep on going.

> >

> > It's depressing for me but I'm happy to read your adventures ;)

> >

> > Good luck,

> > Erturk (Simon6809 and Simon6809 Turbo ;))

> >

> > Sent from my iPhone

> >

> > On Jul 25, 2012, at 6:59 PM, "Kip Koon" <computerdoc at sc.rr.com> 

> wrote:

> >

> > > John,

> > >

> > >

> > >

> > > Thank you so much for your suggestions.  I was concerned about 

> the 

> > > ACIA being so low in memory also made me think a about it before 

> I built

> it.

> > > Since I had never built an 8-bit 6809 computer from scratch 

> before 

> > > and

> > this

> > > one had been designed and built with a nongraphic version of 

> Tandy's 

> > > Extended Color Basic in it that was the clincher.  I cut my post 

> 

> > > college computer learning years on Tandy's Color Computers.  At 

> one 

> > > time I had a Coco1, 2 and 3 with 4 floppy drives and a 20BM MFM 

> hard 

> > > drive too.  I thoroughly enjoyed that computer.  So to make a 

> long 

> > > story short, I

> > figured

> > > I could alter the placement of the I/O later once I get my 

> > > proverbial

> > tooth

> > > cut building Grant's 6-chip 6809 computer to the $FFxx region.

> > >

> > >

> > >

> > > In my next project I'll be building SiMon6809 which has a USB 

> port

> > placed at

> > > $D000 which for me is still too low.  The link to Simon6809 

> appears

> > below:

> > >

> > >

> > >

> > > http://www.8bitforce.com/simon6809/

> > >

> > >

> > >

> > > But after it is working , I'll be moving that USB port up to the 

> 

> > > $FFxx region or maybe the $Exxx like SWTPC computers.  I'm not 

> sure 

> > > yet. Maybe eventually I could create a dual memory map version.  

> 

> > > That could be a

> > very

> > > interesting but complex learning experience.  I'd definitely 

> create 

> > > some more wrinkles in my brain working on it. J I'm waiting on 

> some 

> > > supplies,

> > so

> > > it could be a little while.  In the meantime, I'll be brushing 

> up on 

> > > my decoding logic as it applies to 8-bit microprocessor 

> > > applications.  This

> > is

> > > so much fun.  The modern chips we have available make 

> implementation 

> > > so

> > much

> > > nicer.

> > >

> > >

> > >

> > > I have never used Flex9 or even 6800 Flex, so I never really 

> > > considered

> > it.

> > > I'll have to look into it.  I'd like to upgrade the next version 

> 

> > > with a

> > DMA

> > > Floppy disk controller so I can run disk-based OSs Flex, OS-9 

> and

> > NitrOS-9

> > > and Uniflex.  I'm game for it all.  It will be like old times, 

> but

> > better.

> > > Isn't dreaming FUN?!  Let me go for now.  I'll keep you all up 

> to 

> > > date as things progress.

> > >

> > >

> > >

> > > Kip

> > >

> > >

> > >

> > > -----Original Message-----

> > > From: coco-bounces at maltedmedia.com 

> > > [mailto:coco-bounces at maltedmedia.com]

> > On

> > > Behalf Of John Kent

> > > Sent: Tuesday, July 24, 2012 8:17 AM

> > > To: CoCoList for Color Computer Enthusiasts

> > > Subject: Re: [Coco] FW: My 6809 Computer is Working!

> > >

> > >

> > >

> > >

> > >

> > > Kip,

> > >

> > >

> > >

> > > You could add a floppy disk controller to it.

> > >

> > > I tend to follow the South West Technical Products Computer 6809 

> 

> > > memory

> > map

> > > in my FPGA designs as it allows for more contiguous RAM.

> > >

> > > The SWTPc has RAM mapped from $0000 to $DFFF, giving 56K of 

> RAM.

> > >

> > > $E000 - $EFFF is used for I/O. Typically I/O is mapped in 10 x 

> 16 

> > > bytes slots.

> > >

> > > They have 10 slots because they use a decade decoder (74LS42 ?)

> > >

> > > $F000 - $F7FF can be used for EPROM such as one of the OS9 boot 

> ROMs.

> > >

> > > It can also be used for a DMA Floppy disk controller.

> > >

> > > $F800 - $FFFF is used for a Boot ROM, such as SBUG.

> > >

> > > It's also used for an OS9 boot ROM if you want to run OS9.

> > >

> > > Some of the SWTPC boards use a 16 byte write only register file 

> 

> > > mapped at

> > > $FFF0 to $FFFF to map in up to 1MB of RAM in 4Kbyte blocks. The 

> 

> > > extra

> > memory

> > > can be used for running OS9 level 2 if you can get hold of it or 

> 

> > > UniFlex, although that might need a DMA Floppy disk controller.

> > >

> > >

> > >

> > > The SWTPc memory map is more intended for running the Flex disk 

> 

> > > operating system, so that things like BASIC and so on can be 

> loaded 

> > > off floppy disk into memory.

> > >

> > > I'm not sure if it's possible to design a hybrid SWTPc that also 

> 

> > > supports CoCo hardware as well.

> > >

> > >

> > >

> > > Kip, you'd be better off using $E000 for I/O rather than $A000 

> as 

> > > that

> > would

> > > give you more continuous RAM.

> > >

> > > On the SWTPC Flex9 sits at $C000 - $DFFF where you have the 

> ROMed 

> > > Basic interpreter. If you have that as RAM, you might be able to 

> 

> > > read the BASIC ROM from an I/O location and copy it into RAM. 

> You 

> > > could have two

> > >

> > > 8 bit latches/ D flip flops (74LS374s)  at an I/O location 

> somewhere 

> > > that you write the address to and read the contents of the ROM 

> back 

> > > and write

> > it

> > > into RAM.

> > >

> > >

> > >

> > > To run Flex9 you need a floppy disk controller (or an IDE drive) 

> a 

> > > 6850

> > ACIA

> > > at $E000-$E00F and that's about it. There is a lot for free 

> Flex9

> > software

> > > out there.

> > >

> > >

> > >

> > > It's a bit off the topic for the CoCo list sorry. A CoCo 1 or 2 

> 

> > > wouldn't

> > be

> > > too hard to build. the 32K SRAM chips out of a 486 cache have a 

> 20 -

> > 25nsec

> > > access time, so you wouldn't need a SAM to interleave the CPU 

> with 

> > > the

> > VDG

> > > for video accesses.

> > >

> > >

> > >

> > > John.

> > >

> > >

> > >

> > > On 23/07/2012 11:26 AM, Juan Castro wrote:

> > >

> > >> Suggestion: external clock circuitry so the much more 

> ubiquitous 

> > >> 6809E

> > >

> > >> can be used. (If the lack of MRDY won't screw up with your

> > >

> > >> multiprocessing

> > >

> > >> ideas.)

> > >

> > >>

> > >

> > >> Juan

> > >

> > >>

> > >

> > >> On Sun, Jul 22, 2012 at 2:24 AM, Kip Koon < <mailto:

> > computerdoc at sc.rr.com>

> > > computerdoc at sc.rr.com> wrote:

> > >

> > >>

> > >

> > >>> Hello Everybody,

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> I'd like to report that I finally got Grant's 6-chip 6809 

> computer

> > > working!

> > >

> > >>> It is so wonderful to actually build your own computer from 

> > >>> scratch

> > >

> > >>> and see your creation come to life and display "Hello World" 

> which 

> > >>> is

> > >

> > >>> actually the first program I typed in. J  It's kind of 

> tradition

> > >

> > >>> anyway.  I've seen several small microprocessor projects on 

> the

> > >

> > >>> internet being demoed with the standard "Hello World" message. 

>  It

> > >

> > >>> was my first C++ program years ago anyway.

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> I built the first version of my 6809 computer exactly like 

> Grant's

> > >

> > >>> 6-chip

> > >

> > >>> 6809 computer with exactly the same memory map as shown below. 

> It 

> > >>> has

> > >

> > >>> 32KB of ram at $0000 to $7FFF with the 16KB eprom at $C000 to 

> 

> > >>> $FFFF

> > >

> > >>> programmed with Grant's 6809 Extended Basic.  The Basic 

> > >>> Interpreter

> > >

> > >>> actually starts at $DB00, so there is a lot of empty eprom 

> space

> > >

> > >>> leftover for some type of monitor - 6.75KB I believe.

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> The initial memory map is as follows:

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> $0000

> > >

> > >>>

> > >

> > >>>    |          32KB RAM

> > >

> > >>>

> > >

> > >>> $7FFF

> > >

> > >>>

> > >

> > >>> $8000

> > >

> > >>>

> > >

> > >>>     |          8KB Unused

> > >

> > >>>

> > >

> > >>> $9FFF

> > >

> > >>>

> > >

> > >>> $A000

> > >

> > >>>

> > >

> > >>>     |          8KB I/O Space: MC68B50 ACIA chip is addressed 

> at

> > > $A000-$A001

> > >

> > >>> (Address Bus is not fully decoded.  The ACIA appears 

> throughout 

> > >>> the

> > >

> > >>> $A000-$BFFF address space.)

> > >

> > >>>

> > >

> > >>> $BFFF

> > >

> > >>>

> > >

> > >>> $C000

> > >

> > >>>

> > >

> > >>>     |          16KB EPROM programmed with 6809 Extended Basic

> beginning

> > > at

> > >

> > >>> $DB00.

> > >

> > >>>

> > >

> > >>> $FFFF

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> Well the obvious next step is to extend the ram up to the 

> > >>> indicated

> > >

> > >>> $9FFF limit in the design.  So I did!  I had a small supply of 

> 

> > >>> 32KB

> > >

> > >>> ram chips I had robbed from an old 486 motherboard not knowing 

> at 

> > >>> the

> > >

> > >>> time that they were 32KB ram chips.  Was I surprised when I 

> looked

> > >

> > >>> them up on the internet.

> > >

> > >>> I used one for the initial 32KB of ram and added a second one 

> at

> > >

> > >>> $8000 - $9FFF for another 8KB of ram.  Obviously I just used 

> part 

> > >>> of

> > >

> > >>> the second 32KB ram chip.  Later on, I plan to use more after 

> I

> > >

> > >>> rearrange the I/O space.

> > >

> > >>> Now

> > >

> > >>> my little 6809 computer has 40KB of ram space located from

> > >

> > >>> $0000-$9FFF!  So the memory map is modified as follows:

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> $0000

> > >

> > >>>

> > >

> > >>>    |          40KB RAM

> > >

> > >>>

> > >

> > >>> $9FFF

> > >

> > >>>

> > >

> > >>> $A000

> > >

> > >>>

> > >

> > >>>     |          8KB I/O Space: MC68B50 ACIA chip is addressed 

> at

> > > $A000-$A001

> > >

> > >>> (Address Bus is not fully decoded.  The ACIA appears 

> throughout 

> > >>> the

> > >

> > >>> $A000-$BFFF address space.)

> > >

> > >>>

> > >

> > >>> $BFFF

> > >

> > >>>

> > >

> > >>> $C000

> > >

> > >>>

> > >

> > >>>     |          16KB EPROM programmed with 6809 Extended Basic

> beginning

> > > at

> > >

> > >>> $DB00.

> > >

> > >>>

> > >

> > >>> $FFFF

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> Then I added an MC68B21 PIA chip decoded to $A004 - $A007 and

> > >

> > >>> connected an

> > >

> > >>> AY-3-8910 Programmable Sound Generator Chip to the two ports 

> of 

> > >>> the

> > >

> > >>> PIA chip.  I was having some problems with the initial testing 

> of 

> > >>> the

> > >

> > >>> PIA so I added two SN74LS244 Octal buffer chips each one 

> connected 

> > >>> to

> > >

> > >>> 8 LEDs one to each port of the PIA so I could see what the two 

> PIA

> > ports

> > > were doing.

> > >

> > >>> Well, every time I pressed the reset push button, the LEDS 

> changed!

> > >

> > >>> I hadn't even written any code what so ever nor did any exist 

> in 

> > >>> the

> > >

> > >>> eprom, so I knew something was wrong!  As you all might have 

> > >>> guessed

> > >

> > >>> I had not fully decoded the PIA chip to just the $A000-$BFFF 

> > >>> address

> > >

> > >>> range yet!  I had just decoded A3 - A0 address lines.  A15 - 

> A4 

> > >>> were

> > >

> > >>> never used.  No wonder the PIA wouldn't work correctly!  I 

> > >>> couldn't

> > >

> > >>> hardly believe I had made such a gross mistake.  Therefore, 

> the 

> > >>> PIA

> > >

> > >>> chip appeared everywhere in the 64KB address space.  The funny 

> and

> > >

> > >>> most interesting part was, the 6809 Extended Basic still 

> > >>> functioned

> > >

> > >>> perfectly!  WOW!  So now the memory map is updated thusly:

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> $0000

> > >

> > >>>

> > >

> > >>>    |          40KB RAM

> > >

> > >>>

> > >

> > >>> $9FFF

> > >

> > >>>

> > >

> > >>> $A000

> > >

> > >>>

> > >

> > >>>     |          8KB I/O Space: MC68B50 ACIA chip is addressed 

> at

> > > $A000-$A001

> > >

> > >>> (Address Bus is not fully decoded.  The ACIA appears 

> throughout 

> > >>> the

> > >

> > >>> $A000-$BFFF address space.)

> > >

> > >>>

> > >

> > >>> $BFFF                                    MC68B21 PIA chip is 

> addressed

> > at

> > >

> > >>> $A004-$A007 (Address bus is definitely NOT fully decoded, yet. 

>  It

> > >

> > >>> appears everywhere.  Oops.)

> > >

> > >>>

> > >

> > >>> $C000

> > >

> > >>>

> > >

> > >>>     |          16KB EPROM programmed with 6809 Extended Basic

> beginning

> > > at

> > >

> > >>> $DB00.

> > >

> > >>>

> > >

> > >>> $FFFF

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> Although I can use the 6809 Extended Basic, I have yet to see 

> the

> > >

> > >>> power on boot up message.  I have to press reset a couple of 

> times

> > >

> > >>> before I see the OK message prompt.  Can Anyone tell me why?  

> I 

> > >>> think

> > >

> > >>> a capacitor is missing between the reset button and ground, 

> and if 

> > >>> so I

> > > need a value for the cap.

> > >

> > >>> I've tried several resister values a 100uf and 0.1uf capacitor 

> 

> > >>> values

> > >

> > >>> but nothing has worked so far regarding power on reset 

> working

> > >

> > >>> correctly.  The schematic for the initial version of Grant's 

> > >>> 6-chip

> > >

> > >>> 6809 computer is attached as a .png file.  This is the 

> schematic I

> > > started my project with.

> > >

> > >>> I will eventually be adding my additions to a new version of 

> the

> > > schematic.

> > >

> > >>> I'm just not sure yet what I'll use to draw the schematic 

> with.

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> I just received some more hook-up wire so I'll be fixing the

> > >

> > >>> addressing problem with the PIA.  After that, testing the PIA 

> chip

> > should

> > > be easy.

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> My next addition which I am in the middle of adding to my 

> 6809

> > >

> > >>> computer is a UM245R USB Prototype board from FTDI.  Since the 

> 

> > >>> FT245R

> > >

> > >>> chip is a ssop, they put it on a PCB with 24 legs so it will 

> fit 

> > >>> on a

> > >

> > >>> breadboard prototyping design layout just like a real 24-pin 

> chip.  

> > >>> I

> > >

> > >>> love it!  As soon as it is hooked up, I will be programming an 

> 

> > >>> eprom

> > >

> > >>> with the Simon6809 monitor

> > >

> > >>> program.   Simon6809 communicates with the host PC through - 

> you

> > guessed

> > > it

> > >

> > >>> - the USB port!  I can hardly wait to see that working!  You 

> can

> > >

> > >>> google "Simon6809" for further information if you're 

> interested.

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> That's all for now with the continuing saga of my Home Brewed 

> 6809

> > >

> > >>> computer.

> > >

> > >>> My little baby is growing.  It's so exciting!  Take care 

> everyone.

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> Kip

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>>

> > >

> > >>> --

> > >

> > >>> Coco mailing list

> > >

> > >>> <mailto:Coco at maltedmedia.com> Coco at maltedmedia.com

> > >

> > >>> <http://five.pairlist.net/mailman/listinfo/coco>

> > > http://five.pairlist.net/mailman/listinfo/coco

> > >

> > >>>

> > >

> > >> --

> > >

> > >> Coco mailing list

> > >

> > >> <mailto:Coco at maltedmedia.com> Coco at maltedmedia.com

> > >

> > >> <http://five.pairlist.net/mailman/listinfo/coco>

> > > http://five.pairlist.net/mailman/listinfo/coco

> > >

> > >>

> > >

> > >

> > >

> > > --

> > >

> > > <http://www.johnkent.com.au> http://www.johnkent.com.au

> > >

> > > <http://members.optusnet.com.au/jekent>

> > > http://members.optusnet.com.au/jekent

> > >

> > >

> > >

> > >

> > >

> > >

> > >

> > > --

> > >

> > > Coco mailing list

> > >

> > > <mailto:Coco at maltedmedia.com> Coco at maltedmedia.com

> > >

> > > <http://five.pairlist.net/mailman/listinfo/coco>

> > > http://five.pairlist.net/mailman/listinfo/coco

> > >

> > >

> > >

> > >

> > > --

> > > Coco mailing list

> > > Coco at maltedmedia.com

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> >

> > --

> > Coco mailing list

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> >

> 

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