It didn't appear that they had given much
thought to programming the thing to make it
actually work, so that's when they thought
of those computer geeks over in the CS Department.
So anyhow, the photo above shows a later version
of the tree. It had platforms for choir members
and the lights were to "dance" with the music. The
diagram at right shows how the lights were strung
in rows and columns.
The first program consisted of a menu of patterns
and the operator had to tap the button, say, "B"
for "bars up", in time to the music. I don't recall
how the background and colors were selected, but
it was some combination of keys. The programmer,
of course, couldn't run it because he wasn't "artistic"
enough, so there was another operator for the
performances.
(Ya, right)
So we would have a different show every night.
The show was all planned out, and then instead of
green bars the operator would get red columns or something.
That would throw off his plan and it would never
recover. Much like sight-reading piano music but
you don't have the music nor have you practiced.
So we got bars up instead of columns and diagonals
instead of snow.
The audience loved it anyway.
The electronics guys had it all figured out. Too bad
their perception of the real world didn't match
with reality. From a human factors standpoint, it
was a disaster waiting to happen, my first (bad)
experience with user interfaces. I did what the
hardware guys said and it was really easy to use,
until the lights went down and the music came up
in front of 3,000 people (no exaggeration!). Then
the adrenaline started flowing, nerves got tense,
thought processes got cloudy and oh, my. If you've
ever played at a piano recital you know what I'm
talking about. You practice and practice and then
you make a mistake and it throws you off and you
never completely recover, and when your little
song is done, you're just relieved. Nerves were
like that running that first Christmas tree.
The whole thing was run on a PC (not XT -- no hard drive
and the BIOS wasn't smart enough to handle one), so
everything (compiler, programs, DOS) was stored on one
very slow 360K diskette. Upon boot, the whole schmear
was copied into a RAMdisk in main memory, otherwise
it took way too long to load programs between songs.
(They only allowed about 3 seconds.) So a batch job
plus all the executables in RAM could just keep up
nicely.
The highlight (lowlight?) of this era was when
the operator made a big boo-boo. We had this random
pattern where the various strings of lights would
blink randomly. We had it on the menu as something
like "T" for "Twinkle", but the "artists" called it
the "crazy quilt". OK, so one evening during the
Hallelujah Chorus when everything is jumping around
and flashing like crazy, he hit "Q" for "Quilt".
Unfortunately, it was actually for "Quit", so there
he was with the music going wild and a green,
otherwise non-functional, tree. As I recall we had
to reboot from floppy, which meant load all the
programs into the RAMdisk and restart the program,
about a 30 second deal, during which the audience
was probably wondering. Why? Because we had to run
the boot-up routine that programmed the 8255 controller
chips every time the program started. And I reckon
it was partly my fault; I should have seen the "quilt"
and "quit" confusion coming down the road, but as I
said it was my first experience with such interfaces
and I'm not the sharpest tack on the bulletin board
when it comes to "people" stuff.
About the tapping the keyboard -- the electronic
gurus figured that it would just kind of keep time
to the music and you could use the up and down
arrows to speed it up or slow it down. They knew
slightly less than nothing about music, and the
operator knew precious little (hey, the musicians
were all in the orchestra or on stage). If you're
0.1 seconds off, it really looks bad. Anyhow,
the only way to keep time was to have a human
keep the time.
|
