FizzBuzz in 6502 assembler
FizzBuzz is an extremely basic competence test for programmers. So I thought I’d write a version extremely in BASIC. Here it is in BBC Basic’s embedded 6502 assembler. For added geek points I used a 6502 emulator written in Perl to develop it on.
Just don’t ask why.
10 REM FizzBuzz in 6502 assembler 20 DIM code% 1000 30 OSWRCH = &FFEE 40 OSNEWL = &FFE7 50 work = &70 60 DIM FizzM 4 : $FizzM = "zziF" 70 DIM BuzzM 4 : $BuzzM = "zzuB" 80 FOR pass% = 0 TO 3 STEP 3 90 P%=code% 100 [opt pass% 110 120 .FizzBuzz LDA #1 130 LDX #3 140 LDY #5 150 .FB1 SEC 160 DEX 170 BNE FB2 180 JSR Fizz 190 LDX #3 200 .FB2 DEY 210 BNE FB3 220 JSR Buzz 230 LDY #5 240 .FB3 BCC FB4 250 JSR PrDecimal 260 .FB4 PHA 270 JSR OSNEWL 280 PLA 290 CLC 300 ADC #1 310 CMP #101 320 BCC FB1 330 RTS 340 350 .Fizz PHA 360 LDX #3 370 .Fizz1 LDA FizzM, X 380 JSR OSWRCH 390 DEX 400 BPL Fizz1 410 CLC 420 PLA 430 RTS 440 450 .Buzz PHA 460 LDY #3 470 .Buzz1 LDA BuzzM, Y 480 JSR OSWRCH 490 DEY 500 BPL Buzz1 510 CLC 520 PLA 530 RTS 540 550 .PrDecimal STA work 560 PHA 570 TXA 580 PHA 590 LDA #0 600 PHA 610 .PrDec0 LDX #8 620 LDA #0 630 .PrDec1 ASL work 640 ROL A 650 CMP #10 660 BCC PrDec2 670 SBC #10 680 INC work 690 .PrDec2 DEX 700 BNE PrDec1 710 CLC 720 ADC #ASC"0" 730 PHA 740 LDX work 750 BNE PrDec0 760 .PrDec3 PLA 770 BEQ PrDec4 780 JSR OSWRCH 790 JMP PrDec3 800 .PrDec4 PLA 810 TAX 820 PLA 830 RTS 840 ] 850 NEXT
March 20th, 2007 at 9:30 am
An interesting thread you spotted there.
Working on flight software I’m always amazed when people solve the problem and then waste hours making it smaller/faster/more obfuscated/harder to test & debug.
“Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.”
Brian W. Kernighan
Still, it would allow me to weed out those programmers who wouldn’t fit into our team.
March 20th, 2007 at 12:12 pm
“Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it.â€
Yes, I always liked that quote. It’s only really true if ‘cleverness’ == ‘trick programming’ though. If you use as much cleverness as possible to write code that’s testable, decoupled, modular you’re in good shape.
I’d be interested to learn how you handle your testing Nick. I’m doing a bit of work on the Perl implementation of the Test Anything Protocol at the moment. TAP started out as Perl’s notation for passing test results to a harness for analysis. We’re trying to popularise its use with other languages at the moment so it’d be useful to find out something about your testing culture.
March 20th, 2007 at 5:40 pm
We have use cases that someone manually works through.
We’re migrating to an XML based method where human readable documents are also the test script.
BTW we’re the sort of organisation that gets picky about vague requirements so we’d need to be pretty clear whether numbers divisible by five and three should be “fizz-buzz” or “fizzbuzz” - especially as the little detail changes the implementation.
March 20th, 2007 at 5:45 pm
XML != human readable - use YAML instead :)
So you’re not doing unit testing?
March 21st, 2007 at 10:11 am
“XML != human readable”
It is when used with a style sheet :) That’s how we use it for software configuration/customisation too.
We don’t do unit testing on this project - which I find kind of freaky - but we do on some of our others.
March 23rd, 2007 at 2:39 pm
Just out of interest I tried three versions on SunOS5.7 here at work.
Language:
Source Code Size:
Executable Size:
Time: real -0.0, user 0.0, sys 0.0
Language: Ada - as small as I could write it
Source Code Size: 294 bytes
Executable Size: 1163584 bytes (!) - 571 units included in link closure
Time: real 0.00, user 0.00, sys 0.00
Language: C - smallest version I could find on t’internet
Source Code Size:184 bytes
Executable Size:4688 bytes
Time: real -0.00, user 0.00, sys 0.00
Language: perl - smallest version I could find on t’internet
Source Code Size:63 bytes
Executable Size:n/a
Time: real -0.03, user 0.00, sys 0.03
One you place value on readability all the source code starts to head towards a similiar size:
I rewrote the Ada to satisfy RTCA DO-178B and it occupied 439 bytes. K&R C took 290 bytes. Readable Perl just under 200 bytes.
What is more interesting to me is how the the shortest solutions write “FizzBuzz” explicitly, not using concatenation, so the string operations in perl don’t actually give it an advantage.
A Perl version using concatenation comes in at 87 bytes, without 63 bytes.
March 23rd, 2007 at 4:09 pm
I can do 61 bytes in Perl :)
print$_%3*$_%5?$_:($_%3?Bu:$_%5?Fi:FizzBu).zz,”\n”for 1..100
Where’s the short one you found Nick?
And, yes it’s interesting that having a fourth path for ‘FizzBuzz’ is smaller.
March 23rd, 2007 at 4:19 pm
Sixty bytes actually - it runs without a newline.
March 23rd, 2007 at 4:32 pm
Actually I can do 55 bytes in Perl:
print(($_%3?”:Fizz).($_%5?”:Buzz)||$_,”\n”)for 1..100
And that doesn’t have a fourth route for FizzBuzz.
March 23rd, 2007 at 5:45 pm
54:
print+($_%3?”:Fizz).($_%5?”:Buzz)||$_,”\n”for 1..100
March 24th, 2007 at 5:18 pm
63 bytes was in one of the comments on your link.
Your 54 byte solution is more readable than your 61 byte version too.
March 24th, 2007 at 5:26 pm
Yeah, I noticed that they were getting more readable. Verbosity != readability :)
March 24th, 2007 at 8:56 pm
Yeah, but I could give the 54 byte solution to some guys on military software projects and they wouldn’t be able to tell me what it did. Scary, no?
March 24th, 2007 at 10:23 pm
Aye. I guess they have different priorities :)
April 8th, 2007 at 2:48 pm
[...] FizzBuzz resuelto en ensamblador del micro Motorola 6502, porque con 8bits basta [...]
May 1st, 2007 at 9:20 am
I was in such a bad mood this morning and coming across some BBC Micro assembler mnemonics has really cheered me up, thanks. I’m almost considering getting the old Model B out of the loft and trying to get a Token Ring network up and running. Almost.
June 5th, 2008 at 12:54 pm
PHP comes in at an obese 80 bytes including open and close short php tags(74 without any newlines or open close php tags:
for($x=1;$x