Re: Is it possilble to use timer interrupt in Apple II?

["Albert D. Kallal" <PleaseNOOOsPAMmkallal@msn.com>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message


>> Contrast the above behavior as to when using Applesoft BASIC and you 
>> executed a load from the floppy drive - all the code and virtually 
>> everything else like the display froze during the disk drive 
>> load/activity .
>
> Because DOS and ProDOS disk operations do not poll between blocks, not
> because of anything fundamental.
>

Yes, that was EXACTLY my point. I did not claim there was anything
fundamental here, but I was just pointing out how smooth and nice
the UCSD system was. There no question that the applesoft system
could have bee built differently, but it was not. I did think
there was ANY OTHER possibility or conclusion in what I had pointed
out? Was there????

>
> Although you used it only as an example, it is not difficult to see
> how one design team could choose to implement it and another might
> not.
>

Sure, I have software running on mainframe systems in several countries
around the world. The developers that use my editor and screen builder
systems will find that in some places I do flush out the type ahead buffer.

As for the disk drive and the ability of UCSD to poll the keyboard between 
each disk block read, I am betting that a fast typist would be able to skip 
some chars with the floppy, but with a hard disk, it was even smoother.

Really, all I can say here is that at the end of the day the UCSD was just a 
smooth well behaved system that I can't ever recall it freezing up on me as 
compared to the applesoft environment in which I did have to resort to the 
rest-button many a time...

I have many fond memories of working in applesoft and even in the 6502 
assumer.

However, my experience in writing lots of software in the UCSD Pascal system 
was nothing short of an great all around high quality experience.

That little tiny 8 bit 6502 was sure the little engine that could! Despite 
such limited hardware, the overall experience of the UCSD was high quality, 
ran smooth, ran well, and was simply real a joy to use. The UCSD system 
changed my mind that little desktop computers were not toys anymore.

On the other hand, I did bust up and wear out the "L" key playing castle 
wolfenstein on that same computer. If I recall correctly, I flipped the key 
underneath with one of the shift keys to
return that L key to working order.

I have not fired up my Apple II in many years. I still have that apple II, 
and it has a working 10 meg Dovong hard drive attached to it...


-- 
Albert D. Kallal    (Microsoft MVP)
Edmonton, Alberta Canada
pleaseNOOSpamKallal@msn.com