A task for cool programmers ;)

Background:

The son began to get acquainted with programming. On BASIC 48.
Naturally, I started playing with PLOT and DRAW. And I finished the game... :)

And now - attention, question!
Explanation of what the program will draw (without typing it):

10 PLOT 60.90
20 DRAW 100.10.9999

??

Now type, run and explain again. ;-))

For historians: the effect was discovered by Denis Svetashov. :))

Good luck!
Vitalic.

18 Sep 99 22:09, Vitalic Svetashov told Speccyland People about {Problem for
cool programmers ;)}:

VS> 10 PLOT 60.90
VS> 20 DRAW 100.10.9999
VS> Now type, run and explain again. ]

VM> Why is it incomprehensible - DRAW draws 9999 lines 100 pixels long with
VM> a rotation of 10 radians.

Wow!
It turns out that the third parameter in DRAW is the _number_ of _lines_ drawn?
Where does this information come from?
Until now I was in the happy delusion that DRAW c with three
parameters it draws _one_ _arc_ and the 3rd parameter is its angle.
Disappoint me with a specific link. ;)

By the way, you can go the opposite way:
I ask what the same program will draw, but instead of 9999 -> 9998
You, apparently, answer - 9998 lines 100p long with a rotation of 10 rad.
We run it - we explain. Let's? ;)

Good luck!
Vitalic.

... *That's it!* Inscription on the cemetery.

Rulez! Very, I must say, beautiful.

VS> For historians: the effect was discovered by Denis Svetashov. :))

...let’s write it down...

Sincerely, Igor.

[ZX] [Post] [CYCLING] [CINEMA]

-=- e-mail: Igor_Krauk...@zxnet.spb.ru

VS> It turns out that the third parameter in DRAW is the _number_ of _lines_ drawn?
VS> Where does this information come from?
VS> Until now, I was in the happy delusion that DRAW with three
VS> parameters draws _one_ _arc_ and the 3rd parameter is its angle.
VS> Disappoint me specific link. ;)

Disassemble the DRAW command interpretation code in ROM and see for yourself. There
you can clearly see that sometimes DRAW draws lines, sometimes arcs, sometimes stars,
sometimes spirals, and sometimes three-dimensional cubes. Unfortunately, the last two
possibilities, due to numerous ROM errors, are implemented incorrectly. Below
is the required list of '82 ROM fixes:

#1054 <-#00
#1056 <-#c9
#1077 <-#c3
#2871 <-#dd
#3f88 <-#bc

VS> By the way, you can go the opposite way:
VS> I'm asking what the same program will draw, but instead of 9999 -> 9998
VS> You, apparently, are answering - 9998 lines 100p long with a rotation of 10 rad.
VS> Let's run it and explain. Let's? ;)

Have you heard of such a thing as calculation error? - this is what we
observe :(

VM> Disassemble the DRAW command interpretation code in ROM and see
VM> for yourself. There you can clearly see that sometimes DRAW draws lines, sometimes arcs,
VM> sometimes stars, sometimes spirals, and sometimes three-dimensional cubes.
Slava, firstly, I was talking about something else. There is a language - BASIC 48K, there is a
DRAW operator. Show me the description of this language, where it is written that
DRAW “sometimes draws...” - further in the text. And what does “_sometimes_
stars, sometimes... :)” mean - the operator must _always_ perform its
function. What does the ROM disassembler have to do with it? By the way, about him. In my spare time, I will, of course, dig around there. Although, with all the undeniability of your
authority, it is difficult to imagine that from any assembly
text it is “perfectly clear” that it “sometimes draws three-dimensional cubes”

VM> Unfortunately, the last two possibilities, due to numerous ROM errors,
VM> are implemented incorrectly.
That is, it is implied that all this is not a glitch, but built-in features, and
drawing stars even implemented correctly? I beg you, give the format of the DRAW operator for the cases of stars, spirals and three-dimensional cubes.
Preferably, of course, with reference to the original source.
The Spectrum scene has not seen such revelations for a long time. :)
VM> Below is the necessary list of fixes
VM> ROM of the 82nd year:
Senks. Now I can draw stars and spiralsby one operator?

23 Sep 99 23:31, Vitalic Svetashov reported by Vyacheslav Mednonogov about {Problem
for cool programmers ;)}:

VS>>> Until now, I was in the happy delusion that DRAW c three

/skip//skip//skip//skip//skip//skip//skip//skip//skip/

VS> PS By the way, what is a “line 100 pixels long” (from the previous
VS> letters, horizontal and vertical don’t count)?

Relax, you need to develop your sense of humor at least a little :))

p.s. and by the way, don’t even think about flashing the ROM - it was a joke too ;)

VS>> of the previous letter, horizontal and vertical do not count)?

VM> Relax, you need to develop your sense of humor at least a little :))

VM> p.s. and by the way, don’t even think about changing the ROM - it was a joke too ;)

that ROM draws two copper legs instead of stars :)

∙∙∙ hex;music.fanatic [metallica] [madonna] [depeche mode]
... forever trusting who we are.. no, nothing else matters.. (c) metallica

IK> ...let’s write it down...
No... It turned out that this happened before us, in the 14th century. :)

Good luck!
Vitalic.

... Cabbage is always a snack: it’s not a shame to serve it, and it’s not a pity to eat it