Re: Applesoft BASIC

["Bryan Parkoff" <nospam@nospam.com>]

"Jerry" <blip_awanderin_blip@blipyahoo.ca> wrote in message 
news:bXKkg.65962$JX1.5617@edtnps82...
> Mark Percival wrote:
>> Bryan Parkoff wrote:
>>
>>>    I notice what I read documents on the Google search.  It says to use 
>>> $69
>>>and $6A.  I don't know what this is for, but Mark recommends to use $67 
>>>and
>>>$68.
>>
>>
>> $67-$68 = Applesoft text table pointer (Points to the beginning of
>> program text
>>                 default value $0801)
>> $69-$6A = Applesoft variable table pointer - points to the start of
>> simple variable
>>                 space (at the end of Applesoft program text)
>>
>> Source: What's Where in the Apple? By William F. Luebbert
>>
>> -- Mark
>
> Also, when you change $67-$68 (103-104), you have to poke a zero at the 
> address prior.  So for starting your program at $4000:
>
>   POKE 103,1
>   POKE 104,64
>   POKE 16384,0
>   NEW
>
>   or
>
>   RUN PROGRAM-NAME
>
> Applesoft will complain if there is not a zero in the location prior to 
> ($63,$64).
>
> If your program fits between $801 and $1FFF, but its variables do not, 
> start your program with LOMEM: 16384 (if you use HGR), and then you do not 
> need the POKE trick above.
>
> See page 127 in the Applesoft II Reference Manual.  It has a memory map, 
> along with the zero-page locations that control where it stores what.
>
>
>
>
> -- 
> Jerry Penner     e-mail:  remove the blips and _
Jerry,

    I understand now.  Thanks for the information.  I appreciate your help.

Bryan Parkoff