Re: Introducing Slammer!

[mojoehand <mojoehand@gmail.com>]

On Jul 28, 7:36 pm, Ivan X <ivan...@yahoo.com> wrote:
> On 7/27/10 1:42 PM, in article
> 25a9b633-b714-437b-b8b8-d1fdea225...@b4g2000pra.googlegroups.com,
>
> "mojoehand" <mojoeh...@gmail.com> wrote:
> > I haven't looked at Slammer yet, but this method sounds very similar
> > to what was used in "Voyage of the Valkyrie!" by Leo Christopherson.
> > This was a TRS-80 game from 1980. The method was written up in at
> > least one computer magazine at the time. It was quite unique back
> > then.
>
> This had me curious, and I found this page which references what you're
> talking about:http://www.dnull.com/demon/
>
> Unfortunately, I couldn't find a listing or a more detailed description of
> the method, though perhaps I could load the downloadable binary .BAS file
> via some kind of emulator. But yes, it sounds similar, with the exception
> that the program apparently becomes modified once executed, which is not the
> case with Slammer. (Actually, Slammer does momentarily modify the program
> with unlistable binary, but then it tidies itself up when done so the user
> is none the wiser.) I'd certainly be interested in reading more about the
> method if you come across any one of those writeups.
>
> --- news://freenews.netfront.net/ - complaints: n...@netfront.net ---

I can't seem to find any of the details via a Google search, but two
similar methods were used. One was called string packing and the other
line packing. I vaguely recall that if you listed the freshly loaded
BASIC program, most of it looked like either graphics blocks or
garbage. There was a writeup and source code in one of the TRS-80
magazines at the time. I don't remember which, as I used to subscribe
to many computer and electronics magazines. The memories start to
blur. It may have been 80 Micro.

For the time, and considering the primitive graphics and sound of the
TRS-80 Models I and III, these programs were revolutionary. They were
fun  and very fast. Not only was Leo's method unique, but he knew what
it took to write entertaining software. BTW, if you Google, you will
find that Leo is still teaching and he has a web site.

Leo Christopherson is one of many who have earned a place in the
history of personal computing. Another name that comes to mind while
I'm reminiscing is Ward Christensen. How many here remember that name?
No fair Googling :-)