problem with Atari basic

[Ranger03]

If then is not working correctly, usually, a simple if then loop works perfectly but here, then is highlighted.

 

example: dim a$(5):if a$="a" then goto 20

 

the other issue is the lack of an inkey$ command, what can other commands can i use (my memory is not that great so poking 24/7 is out of the question)

[Frankie]

In your example you can remove goto;

10 if x=5 then 30

20 goto 100

[Frankie]

As for inkey$ - A quick google search

 

As mentioned earlier, the version of BASIC for Atari's eight-bit computers has no built-in statement designed specifically to retrieve a single keypress. However, you can achieve the same effect by first opening a channel to the keyboard device with the statement OPEN #1, 4, 0, "K:", then using GET#1 to retrieve character values. (Any unused file number in the range 17 can be substituted for the 1 in these statements). The main difference between the Atari's GET#, and the INPUT$ and GET commands described above, is that GET# returns character code values rather than string characters, so GET# must always be followed by a numeric variable. If characters are desired, the CHR$ function can be used. Also, note that GET# waits for a key to be pressed.

 

To modify the first example program segment in this article for eight-bit Ataris, you must first add lines to open the channel for input and set up the testing variable:

 

100 OPEN #1, 4, 0, "K"

110 DIM K$(1)

This needs to be done only once in the program, but it must be done before the first GET# command. Then replace line 210 with:

 

210 GET #1, K : K$ = CHR$(K)

You may find it easier to simply check for character code values rather than characters. Refer to your BASIC manual for a complete list of Atari ASCII codes. For example, you could test for a RETURN keypress with

 

300 PRINT "PRESS RETURN TO CONTINUE."

310 GET#1, R:IF R< >155 THEN 310

[russg]

As for inkey$ - A quick google search

 

As mentioned earlier, the version of BASIC for Atari's eight-bit computers has no built-in statement designed specifically to retrieve a single keypress. However, you can achieve the same effect by first opening a channel to the keyboard device with the statement OPEN #1, 4, 0, "K:", then using GET#1 to retrieve character values. (Any unused file number in the range 17 can be substituted for the 1 in these statements). The main difference between the Atari's GET#, and the INPUT$ and GET commands described above, is that GET# returns character code values rather than string characters, so GET# must always be followed by a numeric variable. If characters are desired, the CHR$ function can be used. Also, note that GET# waits for a key to be pressed.

 

To modify the first example program segment in this article for eight-bit Ataris, you must first add lines to open the channel for input and set up the testing variable:

 

100 OPEN #1, 4, 0, "K"

110 DIM K$(1)

This needs to be done only once in the program, but it must be done before the first GET# command. Then replace line 210 with:

 

210 GET #1, K : K$ = CHR$(K)

You may find it easier to simply check for character code values rather than characters. Refer to your BASIC manual for a complete list of Atari ASCII codes. For example, you could test for a RETURN keypress with

 

300 PRINT "PRESS RETURN TO CONTINUE."

310 GET#1, R:IF R< >155 THEN 310

line 100 needs a colon in the quotes OPEN #1,4,0,"K:"

 

devices for OPEN are:

C: recorder

D(n): disk drive

E: screen editor

K: key press

P: printer

R(n): serial port

S: screen (how?) you can only output to the screen

 

I think E: and K: do the same thing.

no E: can only 8, output,

12 keyboard input & screen output

13 screen input & output (from Poole and McNiff 'Your Atari Computer"

 

You had it in the paragraph correct.

I think, don't use "E:"

Edited September 5, 2018 by russg

[Keneg]

If then is not working correctly, usually, a simple if then loop works perfectly but here, then is highlighted.

 

example: dim a$(5):if a$="a" then goto 20

 

the other issue is the lack of an inkey$ command, what can other commands can i use (my memory is not that great so poking 24/7 is out of the question)

You need a line number. You cannot go to a line number in immediate mode. I tested on my 130XE and it works fine in a program.

[Kyle22]

If you just want to read a keypress, do poke 764,255, c=peek(764): if c=(desired key code) then goto whatever.:poke 764,255 to reset it again

 

easiest way. Poke it with 255 first to clear it, read it, then poke it back to $FF to clear it again after you're done with it.

[Ranger03]

If you just want to read a keypress, do poke 764,255, c=peek(764): if c=(desired key code) then goto whatever.:poke 764,255 to reset it again

 

easiest way. Poke it with 255 first to clear it, read it, then poke it back to $FF to clear it again after you're done with it.

so if i was to make a text adventure, i would need to poke the same address everytime i wanted input?

[+Nezgar]

so if i was to make a text adventure, i would need to poke the same address everytime i wanted input?

 

If you wanted to input lines of text for a text adventure, followed by a carriage return, you can skip the OPEN E:/K: etc, and just simply use INPUT command, DIM'd appropriately of course (intentionally small here for demonstration...)

10 DIM INPUT$(10)
20 INPUT INPUT$
30 PRINT INPUT$

RUN
?THE QUICK BROWN FOX
THE QUICK

Another neat trick to ditch the "?" at each input is to use IOCB #16, which BASIC treats as #0, described here: http://www.page6.org/archive/issue_32/page_12.htm

10 DIM INPUT$(10)
20 INPUT #16,INPUT$
30 PRINT INPUT$

RUN
THIS IS A TEST
THIS IS A

... and make your own prompt:

10 DIM INPUT$(10)
20 ? "COMMAND-->";:INPUT #16,INPUT$
30 PRINT INPUT$

READY
RUN
COMMAND-->THE QUICK BROWN FOX
THE QUICK

[Ranger03]

flipping through compute's first book of Atari Graphics. just...wow

 

really good stuff

[+Larry]

You need a line number. You cannot go to a line number in immediate mode. I tested on my 130XE and it works fine in a program.

 

Rats! Your beat me to it.

 

I spotted that right off, but still fired up my XL to make sure.

 

-Larry