Questions tagged [applesoft-basic]
For questions related to the Applesoft BASIC interpreter and language.
33
questions
7
votes
1
answer
183
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Did any AppleSoft language enhancements patch CHRGOT?
Some BASIC language enhancements for Commodore 8-bit machines, such as the 1982 DOS Wedge, worked by patching the CHRGOT routine. Even though BASIC is in ROM, every byte that is fetched from a ...
- 32.3k
8
votes
1
answer
240
views
Why did ProDOS trace Applesoft?
When running an Applesoft program under ProDOS, BASIC.System watches for OS commands by looking for PRINT statements that start with Ctrl+D. This is similar, but not equivalent, to the DOS behavior. ...
- 8,240
2
votes
1
answer
253
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Motivation for DOS 3.3 using I/O hooks rather than ampersand-hook
AppleSoft BASIC is designed so that if it encounters an ampersand while processing a program, it will jump to address $03F5, allowing code there to examine what follows and process it suitably. While ...
- 32.3k
15
votes
1
answer
1k
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How are the randomizer values on the Apple II maintained?
Looking at a comment on this question, it reminded me of how there are two memory locations in the Apple II zero page that are used for random number generation: 0x4E and 0x4F (78 and 79, respectively)...
- 15.1k
8
votes
2
answers
1k
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Apple IIe SYNTAX ERROR
I inherited an old Apple IIe computer. I have a dual disk drive and connected to a modern TV screen as the original monitor was fried. On turning on the computer, nothing happens except "Apple ][&...
9
votes
2
answers
874
views
Extensions to Apple BASIC with ampersands
I have a vague recollection of some early software that extended the Apple II BASIC language, though I'm not sure if this was Integer or Applesoft BASIC.
It provided more features for the language by ...
- 3,482
11
votes
1
answer
561
views
Can you read the character definitions (font) in an Apple II using PEEK in Applesoft BASIC?
Can you read the character definitions (font) from ROM in an Apple II using PEEK in Applesoft BASIC? You can do this on some other computers e.g. Sinclair ZX81, Commodore 64, and Amstrad PC1512, but ...
- 493
14
votes
1
answer
693
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Why does Applesoft BASIC get confused by a nonzero value at $0800?
Applesoft BASIC programs start at location $0801 in memory (usually). If you put a nonzero value at address $0800, though, you get an error when you try to run the program:
?SYNTAX ERROR IN 65124
...
- 8,240
6
votes
1
answer
202
views
What determines the amount of space occupied by an Applesoft BASIC program?
I've been writing an Applesoft BASIC program over the last few months or so (IIgs and IIe, ProDOS 2.4.2 with BASIC.SYSTEM v1.6).
My large BASIC program was sitting at something like 51 ProDOS blocks. ...
- 61
18
votes
3
answers
2k
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What does this line: `T=C/2=INT(C/2)` do? Why is it valid syntax?
I do not understand line 80 of the short Applesoft BASIC program below. Didn't even know it was possible to have a single instruction be T=C/2=INT(C/2). Naturally, I tried breaking this line up / ...
- 189
9
votes
4
answers
723
views
Applesoft (pseudo) Random Numbers - alternatives?
What are the alternatives (with examples on how to implement) to Applesoft RND(1) command? I have read of people using a completely different algorithm by poking machine code stored in a DATA ...
- 91
9
votes
1
answer
1k
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Why does the Applesoft BASIC have shapes?
Why did Apple include shapes in Applesoft BASIC? There are no sprites on the Apple II, but shapes provide a simple vector drawing tool. As graphics go the shapes are kind of an odd duck, they provide ...
- 2,272
8
votes
2
answers
2k
views
Are there standalone emulators of Applesoft Basic?
My only retrocomputing desire is to program in Applesoft Basic and relive the Apple II days from the 1980's. Playing games is of no particular interest to me. I just want to use a keyboard, not a ...
- 83
26
votes
4
answers
5k
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Why was it common to reference memory locations using negative numbers on some BASICs?
If you had an Apple II, it was common in BASIC to reference memory locations above the 32K point by using a negative number. For example, if you wanted to click the speaker you would PEEK/POKE -16336 ...
- 15.1k
2
votes
2
answers
252
views
INPUT with comma vs. semi
I certainly don't recall this at the time, but I'll ask to be sure.
According to the GW-BASIC documentation, a semicolon between the INPUT prompt and the variable suppresses the question-mark prompt.
...
- 17.8k
7
votes
4
answers
1k
views
How to use HGR2 (or HGR) on an Apple II
I am a big fan of the TV show lost, and I was trying to make the Dharma Initiative logo.
But at certain point I couldn't add new lines of code and the final part of the logo was cut off. I tried to ...
- 71
6
votes
2
answers
661
views
Where can I find the Applesoft line-drawing algorithm?
I’m trying to make some graphics in Processing that look just like what I’d get on an Apple //e. I think the info I seek is in the ROM disassembly but I can’t find anything by googling. I'm also ...
- 163
3
votes
0
answers
406
views
How do Apple II BASIC compilers compare? [closed]
Programs like The Beagle Compiler allow AppleSoft BASIC or other Apple II BASIC variants to be compiled. How do the compilers compare in terms of compatibility with AppleSoft language features? Eg how ...
- 2,272
4
votes
0
answers
322
views
How to use IIgs enhanced graphics modes in AppleSoft BASIC with System 6?
There are many packages that let you use the enhanced graphics modes of the IIgs in AppleSoft BASIC. However most packages like Iconix do not like System 6 so they have to run off disks and not the ...
- 2,272
10
votes
4
answers
2k
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What are the rules for Applesoft BASIC formatting for code?
What are the rules for Applesoft BASIC formatting for code? I've been doing some BASIC coding and noticed that:
10 input "some question?"; name$
Will be reformatted as:
10 INPUT "some question?";...
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5
votes
1
answer
402
views
1980's ROM used which exp(n) algorithm?
In 1980's ROM (Apple IIe, Commodore 64, VIC-20, ...) which algorithm is used to compute exp(x), and where do the coefficients below come from? (Chebyshev, Remez, Pade, ...)
.byte $71,$34,$58,$3E,$...
- 51
2
votes
1
answer
378
views
Turn off Apple IIe sound
Is there a way to disable sound output on the Apple IIe from Applesoft Basic? Can't seem to find this in any of the documentation or online.
Update: Found this
From http://www.calormen.com/jsbasic/...
- 1,160
6
votes
2
answers
423
views
How can you reset the behavior of ONERR in AppleSoft BASIC?
In an Applesoft BASIC program you can use the standard MS-BASIC ONERR statement to perform error trapping. For example:
10 ONERR GOTO 100
20 POKE 0, 400 : REM INVALID VALUE WILL CAUSE ERROR
30 END
...
- 15.1k
7
votes
3
answers
798
views
What books did schools use to teach BASIC?
What books would have been used to teach school aged kids BASIC in a classroom setting back when BASIC was in common use? 8-Bit computers commonly came with tutorials to learn BASIC, like A Touch of ...
- 2,272
8
votes
2
answers
409
views
In Applesoft BASIC, does combining statements into a single line speed up execution?
In Applesoft BASIC, does combining statements into a single line speed up execution?
For example, would this:
10 PRINT "HELLO WORLD" : FOR I = 1 TO 100 : PRINT I : NEXT I
Run faster than this:
10 ...
- 183
5
votes
2
answers
960
views
Apple II: Applesoft variable syntax error weirdness
While typing immediate-mode commands in Apple II Applesoft / floating point BASIC, I discovered an odd situation where I will get other programming error messages before a syntax error. Why does it do ...
- 3,551
27
votes
2
answers
4k
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Apple II: Applesoft BASIC memory management
I am trying to write an Applesoft / floating point BASIC program using high resolution graphics and some assembly language code.
My BASIC program is quite large, and after running the program for a ...
- 3,551
10
votes
1
answer
482
views
Apple II: HPLOT crashes system. Why?
While I was writing a program on an Apple IIe, I set up access the graphics page using softswitches, and then tried to draw on it, but the system crashed so hard I had to do a Control - Open Apple - ...
- 3,551
12
votes
4
answers
953
views
At what address do Apple II Applesoft programs get stored?
Online references disagree on whether Applesoft programs were stored at 0x801 (2049) or 0x3001 (12289). A quick test on my OpenEmulator install with an Apple II Plus definitely puts it at 0x801. ...
- 985
35
votes
6
answers
3k
views
Did the LET statement actually do anything in 8-bit Microsoft BASICs?
I know the LET statement was available in AppleSoft and other Microsoft 8-bit BASICs back in the day, but I can't think of a time where I actually used it. Frankly, I get the impression that it was ...
- 15.1k
11
votes
1
answer
2k
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Testing/using a joystick in AppleSoft?
How does one use joysticks in a program on the Apple //?
I have three different joysticks here and I would like to visualize their state (pot and button values), maybe similar to the SDL joystick ...
- 1,029
18
votes
2
answers
2k
views
Apple // screen editing
I've heard mention many times of screen editing commands on the Apple // for fixing typos in BASIC programs (and patching code in the monitor?). I did not learn these growing up, never having the ...
- 1,029
17
votes
3
answers
1k
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What are the differences between the versions of AppleSoft BASIC?
Apple did make some changes to AppleSoft BASIC over the years between the first version on the Apple II and the last version on the Enhanced IIe and IIe card. What are the differences between the ...
- 2,272