Re: 1980 Basic Sought

"Judson McClendon" <judmc@[EMAIL PROTECTED]
> wrote in message 
news:vuKKj.33311$vr3.15170@[EMAIL PROTECTED]
> "Tom Lake" <tlake@[EMAIL PROTECTED]
> wrote:
>> <ArarghMail804NOSPAM@[EMAIL PROTECTED]
> wrote:
>>>

>> a$ = "him"
>> Segment = SSEG(a$)
>> Offset = SADD(a$)
>> DEF SEG = Segment
>> POKE Offset + 1, ASC("e")
>> POKE Offset + 2, ASC("r")
>>
>> This won't trigger garbage collection and is actually
>> faster than the MID$ method.
>
> Tom, I believe you realize this, though you didn't specifically state
> it. But for those not aware, these operations *are* still subject to
> garbage collection that is triggered from other code. For example, if
> the address of the string is retreived, then used later. All of the
> code to use any string address must execute immediately after the
> retreival of the address, and no garbage collection is triggered in
> the meantime. If the address is needed later, it should be retreived
> again later. Even then, it isn't completely safe, if there is string
> handling that could be triggered by interrupts, like a timer. :-)

Right you are, Jud.  Bypassing BASIC's string handling to manipulate
them yourself is definitely risky not to mention ruining ****tability
to other BASIC versions and Operating Systems.  I never use the
technique myself since I usually program in either True BASIC or
Decimal BASIC, both ANSI Standard conforming languages.  The
ANSI standard wisely forbids such things.  Thanks for bringing up
a point I should have made!

Tom Lake