[Coco] CoCo 2 16k.. Upgrade or no?

[Aaron Banerjee]

One of the best ways to find something is to announce publicly that  
you lost it:


5 FOR X=3584 TO 3609
10 READ D
15 POKE X,D
20 NEXT X
25 EXEC 3584
30 DATA 26, 80
35 DATA 142, 28, 0
40 DATA 166, 132
45 DATA 183, 255, 223
50 DATA 167, 128
55 DATA 183, 255, 222
60 DATA 140, 255, 0
65 DATA 38, 241
70 DATA 183, 255, 223
75 DATA 28, 175
80 DATA 57

I think the above program means:

       ORCC   $50
       LDX    $8000          'START OF BASIC
HERE  LDA    ,X
       STA    $FFDF          'MAP TYPE 1 (64K)
       STA    ,X+            'COPY THE BYTE
       STA    $FFDE          'GO BACK TO MAP TYPE 0 (32K)
       CMPX   $FF00          'END OF BASIC AND CARTRIDGE MEMORY
       BNE    HERE
       STA    $FFDF          'NOW THAT YOU'VE GOT BASIC IN THE RAM,  
YOU CAN SAFELY SWITCH TO ALL-RAM MODE
       ANDCC  $AF

This is based on my hen-scratched notes from years ago.
          - Aaron


On Mar 13, 2012, at 8:47 PM, Aaron Banerjee wrote:

>
> Type in PCLEAR 0 and see if the memory increases.   Remember, a 16K  
> computer has 16K of actual RAM (locations 0 - 16383).  A lot of that  
> is used up by BASIC (and the graphics screens).  For 64K machines,  
> normally only 32K is available (locations 0-32767).  There is a way  
> to get it into 64K mode (an all-RAM machine) where you can go poke  
> up BASIC (lots of fun).  I've actually posted the program that does  
> that to this list, and if I can find my notebook, I'll do it again.   
> Basically, it changes the "map type" back and forth while copying  
> over the contents of BASIC.  Once again, BASIC, cartridge memory, I/ 
> O memory, etc take up space, so you'll get no where near the 65536  
> bytes implied by "64K."
>                 - Aaron
>
>
> On Mar 13, 2012, at 8:35 PM, haywire666 at aol.com wrote:
>
>> Thats interesting I don't remember the ?mem thing...
>>
>>
>> Can someone provide a list of the #'s and what they mean?
>>
>>
>> 8487 means 16k?
>>
>>
>> I got 24871 on the coco2 I have on at the moment, does that mean it  
>> only has 48k?
>>
>>
>> Steven
>>
>>
>>
>> -----Original Message-----
>> From: Chad H <chadbh74 at hotmail.com>
>> To: 'CoCoList for Color Computer Enthusiasts' <coco at maltedmedia.com>
>> Sent: Tue, Mar 13, 2012 8:31 pm
>> Subject: [Coco] CoCo 2 16k.. Upgrade or no?
>>
>>
>> Was just given a virgin CoCo2 26-3136.. It's apparently 16k, only  
>> shows 8487
>> from "?MEM".  I already have a spare 64k CoCo, don't really need  
>> this one.
>> I will probably put it up for sell.  Question though.would it be  
>> better to
>> leave it as is or perform a 64K upgrade to it?  I already have  
>> enough spare
>> RAM IC's and sockets and it already has ECB 1.1.
>>
>>
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