Loadstar 236/236.d81/t.party

Text File | 2004-01-01 | 5.3 KB | 218 lines

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      P A R T Y   P I C T U R E

         for the commodore 64
           w/Simons' BASIC

         by Brian Crosthwaite


    Copyright 2005 J&F Publishing,
  1982, 1983, 1984, 2004, 2005
          Brian Crosthwaite
         All Rights Reserved.


    [Party Picture] began in the
1980s. elements of the program are
from the year the C64 was born --
1982. I had this idea of a series of
pictures that slowly unfold on a TV
screen at a party. Not any particular
kind of party, just where people may
be gathering for any length of time,
coming and going to and from living
room, dining room and kitchen, as
people at parties often do.

    On screen pictures would slowly
materialize, people might watch a
while, or glance occasionally at the
screen, and see a new surprise.

    Well, it got it's debut at one of
our anniversary parties. Kids who were
running and playing inside found
themselves trapped by the mesmerizing
pictures that played out on screen.
Soon adults were watching to see what
would come up next.

    The program was a success!

    The pictures I chose, draw out
slowly on the screen. Then after the
program has run it's course, a warning
to turn on audio comes on screen.
After the screen flashes a few times,
LOADSTAR's [Laser Show] loads and
runs.

    The choice to use SB, was based
mostly on the ease in which to access
the hires and multicolor screens and
the myriad commands that it provided.

    My original intent with this
LOADSTAR version was to convert the
program to normal commodore BASIC, but
it proved to be very complicated.
Extended BASICs didn't support many of
the commands used to draw some of the
pictures. This last point is more than
just a command used to plot a dot. I
used some of the idiosyncrasies of the
commands to my advantage.

    Needless to say, conversion would
have taken more time than I had.

    Never to be seen in emulation?

    I tried to find utilities to make
cartridge images. I looked for an
image of Simons' BASIC. I found
nothing. Time was running out. Then
one day I found a site that had a disk
mage of SB! I think it is the UK
version, as I believe that version was
released on floppy. I was now able to
work on the PRG via VICE!

    The disk version is a little
different in that the border default
is red and on the cart it is black (I
think -- i'm in [geoWrite], in [x64],
on a thinkpad at the moment). My
real-time 64 time is limited by my
schedule. I have more access to
[VICE].

    I added a copyright screen, but
the computer's memory was full causing
the program to stop about midway. I
had run out of time, so moving memory
without knowing the layout of SB
memory at this point is not an option.
(I can't find my SB manual anywhere --
drat). So what have you here? This is
the original version. The very PRG
played at parties around the world.
Ok, around Idaho. Ok, a couple of
parties were in Boise.


More notes:

[Laser Show] was renamed to [MENU].
It should load, just press space after
it loads. Running with the disk image
of SB via [VICE], [Laser Show] does
not load and [VICE] freezes. Bummer.

On the SX things look different, so I
wrote an SX version. I hope to post it
at http://noesiscreation.org shortly.

Keep in mind, the drawings unfold at a
rather slow rate since that was the
original idea.

Enjoy!

 BC (aka noesis0)


[DAVE'S ADDENDUMB]

Here at the Tower, we like things nice
and simple. When you choose a program
from our menu, we like to have it load
and run. So here was the problem.
Simon's BASIC loads like BASIC,
expecting to load at 2049. Then, one
would have to LOAD and RUN Brian's
great program.

Bummer!

There had to be a way to get Simon's
BASIC up and running, and then load
the main program -- automatically. And
there is! One thing I have learned
here at the Tower is how to jerk
around BASIC 2.0. It might not be
pretty inside, but by golly, it will
work!

So Party Pictures has three (count
'em, three) Boot programs. PP1 moves
the bottom of basic up to page 155,
then loads and runs PP2. This little
boot uses the old

 IF A = 0 THEN A = 1: LOAD"SIM*",D

routine. Why? Because the file address
in Simon's BASIC puts it where we want
it, and the above is smaller than our
standard BLOAD routine.

Once Simon is in place, PP2 pokes the
ASCII codes for the following into
locations 631 to 640:

 lO"p",8<chr$(13)>rU<chr$(13)>

Then 198 is set to 10. There is one
tiny problem with this. We will come
back to it in a minute.

Then the Bottom of BASIC is moved back
down to page 8, and Simon's BASIC is
executed with SYS 2096 (which is the
SYS call used by Simon's loader
program.

In a second, Simon's BASIC's opening
screen comes up. And that is when I
noticed a problem. The screen
displayed:

READY.
LO"P",8

SEARCHING FOR P
LOADING
READY.
rU

with the cursor sitting on the "U". I
looked again at what was poked into
631 - 640 and discovered it was
supposed to be [eleven] characters.
Our keyboard buffer has only 10
spaces. What to do? What to do!

The answer was to cheat -- and use
location 641 for that last Carriage
Return. 641/642 is supposed to hold
the Bottom of BASIC, but evidently it
is not nearly as important as 43/44. I
got away with it.

The program "P" then boots PARTY
PICTURE, and all else goes on
smashingly. So, three boots for one
program.

Oh, yes. This does not return to
LOADSTASR, so I had to put our "Does
Not Return" boot in front of all the
others.

Clumbsy as all get out. But it works.

 DMM