Chad H | 1 Aug 04:17 2011
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CoCo 2 board layouts (photos)

Anyone know a good source for picking up some photos showing the differences
in the different CoCo boards?

I've found some good information on the differences, but would like to see
actual photographs showing detail.

Only one I have in my possession is from my own CoCo 2: 26-3217

http://www.mediafire.com/?83fy6bfgwyxa1w4

-          Chad

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Chad H | 1 Aug 06:07 2011
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CoCo 2 keyboard ribbon HELP!!??

Ok not sure what happened, but I had taken the cover off my CoCo 2 to blow
it out and take a photo..not like this is the first time I've ever taken the
keyboard loose either.

But upon re-assembly, only about half the keys work!! Ugh.  Looking at the
ribbon cable I didn't see any tears or obvious damage, neither to the
motherboard connector.

I took a multimeter just to see if I could measure continuity on the 'black'
side strips and I could from where it exits the keyboard up to about where
the re-inforced plastic end is.

Right where the re-enforced part starts, it has kind of a 'fold' or crease
in it and continuity starts breaking down.  How do I restore this!??  I've
seen some liquid "trace repair" stuff at Radio Shack before, would this be
what I need?  This is aggravating.  Any help would be appreciated.

Here is what I was thinking of to repair this..  any thoughts?

http://www.radioshack.com/product/index.jsp?productId=3964901

-          Chad

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Phill Harvey-Smith | 1 Aug 13:02 2011
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6502 to 6809 translation

Hi All,

I'm currently trying to translate some 6502 code to run on the 
Dragon/CoCo, all is prety easy except for one thing, the 6809 doesn't 
appear to have one of the 6502 indexed modes namely :

asume that data_addr contains $8000
and y=$20

	lda	(data_addr),y

which will IIRC take look in data_addr, find $8000 and load a from 
$800+$20 = $8020.

the 6809 has
	lda	(data_addr,y)

but this will load a from where data_addr+$20 points to, which is not 
the same thing !

So is there an easy way of translating the 6502 code in a couple of 6809 
instructions ?

Cheers.

Phill.

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(Continue reading)

John Kent | 1 Aug 14:23 2011
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Re: 6502 to 6809 translation

Rather than using Y you might want to use B,

that way

lda (data_addr),y

would become

ldy data_addr
lda b,y

John.

On 1/08/2011 9:02 PM, Phill Harvey-Smith wrote:
> Hi All,
>
> I'm currently trying to translate some 6502 code to run on the 
> Dragon/CoCo, all is prety easy except for one thing, the 6809 doesn't 
> appear to have one of the 6502 indexed modes namely :
>
> asume that data_addr contains $8000
> and y=$20
>
>     lda    (data_addr),y
>
>
> which will IIRC take look in data_addr, find $8000 and load a from 
> $800+$20 = $8020.
>
> the 6809 has
(Continue reading)

Phill Harvey-Smith | 1 Aug 14:42 2011
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Re: 6502 to 6809 translation

On 01/08/2011 13:23, John Kent wrote:
> Rather than using Y you might want to use B,
>
> that way
>
> lda (data_addr),y
>
> would become
>
> ldy data_addr
> lda b,y

Yeah that would work quite a lot of the code seems to be something like

	ldy	#something
loop:
	lda	(indirect),y
	;; do something with a here !
	iny
	bne	loop

So I guess that would become

	ldy	(indirect)
	ldb	#something
loop:
	lda	b,y
	incb
	bne	loop

(Continue reading)

John Kent | 1 Aug 15:26 2011
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Re: 6502 to 6809 translation


On 1/08/2011 10:42 PM, Phill Harvey-Smith wrote:
>
> Yeah that would work quite a lot of the code seems to be something like
>
>     ldy    #something
> loop:
>     lda    (indirect),y
>     ;; do something with a here !
>     iny
>     bne    loop
>
>
> So I guess that would become
>
>     ldy    (indirect)

ldy indirect   ; (absolute addressing no indirect)
where the address "indirect" holds the address you want to point to.
.
>     ldb    #something
> loop:
>     lda    b,y
>     incb
>     bne    loop
>
>
> That would work well I think.
>
> Thanks.
(Continue reading)

John Kent | 1 Aug 16:04 2011
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Re: 6502 to 6809 translation

You also have the U index register which doesn't need the pre-byte 
opcode on the load and store instructions like Y does.

The Super Sleuth disassembler for Flex I think can disassemble 6502, 
6805, 6800 and 6809 code.
I'm not sure if it can do the 6502 to 6809 code conversion.
It can disassemble 6809 absolute code and turn it into position 
independent code I think, which might be useful for OS9/NitrOS9.

looking on google, there used to be a supersleuth manual at

http://os9projects.com/CD_Archive/MANUALS/CSC/SuperSleuth.pdf

but the link doesn't work.
Perhaps others know where it's been moved to.
There is a /6502/ TRANSLATOR. Tr1nsl1tor /6502/ code to /6809/. $75.00 
advertised in Sep82 and Apr82 editions of 68 Micro Journal.

John.

On 1/08/2011 11:26 PM, John Kent wrote:
>
>
> On 1/08/2011 10:42 PM, Phill Harvey-Smith wrote:
>>
>> Yeah that would work quite a lot of the code seems to be something like
>>
>>     ldy    #something
>> loop:
>>     lda    (indirect),y
(Continue reading)

John Kent | 1 Aug 16:08 2011
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Re: 6502 to 6809 translation

http://www.steeman.dk/CoCoManuals/6502-6809Translator.pdf

On 1/08/2011 11:26 PM, John Kent wrote:
>
>
> On 1/08/2011 10:42 PM, Phill Harvey-Smith wrote:
>>
>> Yeah that would work quite a lot of the code seems to be something like
>>
>>     ldy    #something
>> loop:
>>     lda    (indirect),y
>>     ;; do something with a here !
>>     iny
>>     bne    loop
>>
>>
>> So I guess that would become
>>
>>     ldy    (indirect)
>
> ldy indirect   ; (absolute addressing no indirect)
> where the address "indirect" holds the address you want to point to.
> .
>>     ldb    #something
>> loop:
>>     lda    b,y
>>     incb
>>     bne    loop
>>
(Continue reading)

Roger Taylor | 1 Aug 18:48 2011

Re: 6502 to 6809 translation

At 06:02 AM 8/1/2011, you wrote:
>Hi All,
>
>I'm currently trying to translate some 6502 code to run on the 
>Dragon/CoCo, all is prety easy except for one thing, the 6809 
>doesn't appear to have one of the 6502 indexed modes namely :
>
>asume that data_addr contains $8000
>and y=$20
>
>         lda     (data_addr),y
>
>
>which will IIRC take look in data_addr, find $8000 and load a from 
>$800+$20 = $8020.
>
>the 6809 has
>         lda     (data_addr,y)
>
>but this will load a from where data_addr+$20 points to, which is 
>not the same thing !
>
>So is there an easy way of translating the 6502 code in a couple of 
>6809 instructions ?
>
>Cheers.
>
>Phill.

There's no easy way, but then no coding is easy.  Maybe someone 
(Continue reading)

Arthur Flexser | 1 Aug 18:57 2011

Re: 6502 to 6809 translation

Wouldn't lda data_addr,y (without the parentheses) do the equivalent?
Add data_addr to y and load the a register from the address $8020?

Art

On Mon, Aug 1, 2011 at 7:02 AM, Phill Harvey-Smith
<afra@...> wrote:
> Hi All,
>
> I'm currently trying to translate some 6502 code to run on the Dragon/CoCo,
> all is prety easy except for one thing, the 6809 doesn't appear to have one
> of the 6502 indexed modes namely :
>
> asume that data_addr contains $8000
> and y=$20
>
>        lda     (data_addr),y
>
>
> which will IIRC take look in data_addr, find $8000 and load a from $800+$20
> = $8020.
>
> the 6809 has
>        lda     (data_addr,y)
>
> but this will load a from where data_addr+$20 points to, which is not the
> same thing !
>
> So is there an easy way of translating the 6502 code in a couple of 6809
> instructions ?
(Continue reading)


Gmane