qbaisc

Those running linux: Qemu dosn't work quite right with this, but VirtualBox is ok.

You can get a disk image of the floppy for all this from http://eds.dyndns.org/~ircjunk/not_public_dont_open/qbasic.iso
boot up,
if the software asks for a date, just hit enter.
you get the prompt a:/>
type qbasic
hit escape to deny help, we dont need no help :)

Program 1:

type in the following
CLS
PRINT "Hello world"

press alt to get to the menu,
use the arrow keys to get to run, select start and hit enter

In this program:

cls clears the screen
print puts text on the screen

Program 2:

CLS
print "Enter your name mortal ";
input name$
print "I will try to remember to not kill you "; name$

In this program:

the ; on the end of print means to not start a new line
input gets text from the keyboard
name$ makes storage space for what you type in, the $ on the end means its text, and not a number.

Program 3:

CLS
print "Enter your name mortal ";
input name$
if name$ = "master" then goto sorry
print "I will try to remember to not kill you "; name$
end
sorry:
print "Oh its you, sorry master."

In this program:

if/then makes a descision
goto makes the program go to a 'label' instead of the next line
end stops the program
sorry: is a label, labels are program pagemarks

Program 4:

CLS
print "Enter your name mortal ";
input name$
for n = 1 to 10
print "KILL "; name$
next n

This program:

for repeats a block of commands n is a storage space for its counter in this case it counts from 1 to 10, every time it repeats the print command
next tells is where the end of the code to repeat is

Program 5:

CLS
print "Enter your name mortal ";
input name$
for n = 1 to 10
print "KILL "; name$
gosub stall
next n

stall:
for d = 1 to 1000
next n
return

This program:

gosub means to go to a label, but to remember where it was so it can go back again to continue
for d = 1 to 1000 is used as a delay, the process of counting from 1 to 1000 takes the computer a while, the speed will varry depending on how fast the computer is
return tells the computer to go back to where it was after the gosub command

Stop for a min!

ok, our programs are getting bigger and a little harder to read because of it.
We need to start using spacing to keep the code kinda readable, otherwise it all globs into a mess.
One of the things its good to do, is to push over code that is either in a repeat loop or conditional or on their own.

CLS
print "Enter your name mortal ";
input name$
for n = 1 to 10
   print "KILL "; name$
   gosub stall
next n

stall:
   for d = 1 to 1000
   next n
return

this way, its easier to see what is "in" what. It gets more important when your programs get complex

for a = 10 to 1 step -1
for b = 5 to 8
for c = 20 to 30 step 2
print "calculating matrix ";a;"x";b;"x";c
next c
next b
print
next a

for a = 10 to 1 step -1
   for b = 5 to 8
    for c = 20 to 30 step 2
      print "calculating matrix ";a;"x";b;"x";c
    next c
next b
print
next a

See how you can tell a bit easier what is being repeated by what?

screen 9
line (0,0)-(100,100)