4 ms·

Microsoft BASIC was all over the place in the late 70's and early 80's. Before MS-DOS, Microsoft was basically a programming languages company (and they still a

by pan69 6y ago

Microsoft BASIC was all over the place in the late 70's and early 80's. Before MS-DOS, Microsoft was basically a programming languages company (and they still are today). They licensed their BASIC to many other companies, even Apple. https://en.wikipedia.org/wiki/Microsoft_BASIC https://en.wikipedia.org/wiki/Microsoft_BASIC

C1sc0cat 6y ago
And I think most if not all MSBASIC ports for early PC's had a memory leak if you did not break out a FOR loop in the right way. I am a bit rusty but this sows the problem: 10 L = 4720 FOR I =1 TO 1000 STEP 2 30 PRINT I% 35 IF I = l GOTO 6999 40 NEXT 6999 STOP What you needed to do was set I to the end condition as part of the break out of the loop. There was also a lot of aggressive compression done to reduce program size PET in particular munged every thing up putting as many statements on one line as possible
- ajinkyapatil 6y ago
  10 CLS 10 is always CLS
- Starwatcher2001 6y ago
  There was a bug in the TRS-80 basic (which was indeed Microsoft). It had an "on x goto" command that allowed the program to move to different lines depending on the value of a variable: ON X GOTO 200,300,400,500 depending if x=1, x=2,x=3... They'd obviously used the same parser for the standard "If a=1 then goto 200" construct, which allowed an undocumented shortcut of "If a=1, 200" which a few people noticed and started using. However, a later model fixed this, which broke a number of programs.
  - C1sc0cat 6y ago
    ooh I never worked on TRS80's - so they had a version of the Arithmetic IF :-) I could have Told BillG that was bad idea back when I was 19
    - ddingus 6y ago
      x = x + (x < 5) :D No If needed. Atari Basic would allow crazy things like: 10 Goto ((x < 5)*100) + 50 Goes to either line 50 or 150, depending on the comparison result being 1, or 0) Or... Goto (100*x) Faster On goto with no checking, lol. Bill Gates was not involved with the original Atari Basic. That could be purchased on a cartridge for running MS Basic programs.
      - int_19h 6y ago
        Did Atari BASIC use 1 for TRUE? Most BASICs used -1 (i.e. all bits 1), because this allowed the same operators to work for both bitwise and Boolean logic, in the absence of a dedicated Boolean data type.
        ddingus 6y ago
        https://atariwiki.org/wiki/Wiki.jsp?page=Boolean%20Logic%20in%20BASIC https://atariwiki.org/wiki/Wiki.jsp?page=Boolean%20Logic%20i... Yes, it used 0 and 1. And it did not contain bitwise ops. Those were quite the surprise! My first efforts were in Applesoft. Computers at school. Got an Atari machine and programmed the crap out of it. Wrote my own assembler, a few games, etc... Then I got an Apple and finding them in Applesoft was a nice surprise! Prior to that, I thought they were an assembly only thing. The trade off in the Atari basic was doing things mathematically was pretty easy and it generally, but not always, was faster. A few of us wrote fairly complex programs with basically no if statements. Kind of a fun way to think about things back then. I much prefer -1 and 0 and the bit ops, frankly. Internally, I remembered this kind of thing as "really fucking true" as in every bit better signal, or it's false!
        int_19h 6y ago
        The problem with using bit ops as logical is that they don't short circuit. Although it was unfortunately common even in languages that had proper Booleans at the time - e.g. standard Pascal didn't have it, and Turbo Pascal required a compiler directive/switch to enable it, which few even knew of. So it feels worse in retrospect than it actually was back then. On the other hand, one thing that BASIC still has to this day (in VBA) that no other language I can think of does, is bitwise equivalence (EQV) and implication (IMP) operators. Furthermore, since VBA has a Boolean data type, these operators are also available for Booleans; implication comes in handy sometimes.
  - int_19h 6y ago
    This was legal in BASIC from the very first versions of the language: IF a=1 THEN 200 and when they added ON..GOTO, they basically made these two mirrored syntactically. So you could do: IF a=1 GOTO 200 ON a THEN 100,200,300 (I suspect it was simply treated as identical token?)
Theodores 6y ago
In my opinion this was not good. Basic was considered harmful and was possibly the first computer thing to be considered harmful. Line numbers, REM statements, the GOTO statement and much else had to be unlearned by anyone moving on to a professional set of programming tools. At the time we felt enabled rather than held back. But many Microsoft products were like that. The OS on a BBC micro was far ahead of DOS. Then the whole concept of the personal computer took hold even though we had already seen networking. Then the browser wars. Now we learn that Linux is to be in Windows good and proper. So we are getting there in the end.
- int_19h 6y ago
  At the time when BASIC only had line numbers and GOTO, it was comparable to many other popular languages out there. By 80s, when structured programming became the norm, BASIC became more structured as well, with loops and subprograms.

by pan69 6y ago

C1sc0cat 6y ago

And I think most if not all MSBASIC ports for early PC's had a memory leak if you did not break out a FOR loop in the right way. I am a bit rusty but this sows the problem: 10 L = 4720 FOR I =1 TO 1000 STEP 2 30 PRINT I% 35 IF I = l GOTO 6999 40 NEXT 6999 STOP What you needed to do was set I to the end condition as part of the break out of the loop. There was also a lot of aggressive compression done to reduce program size PET in particular munged every thing up putting as many statements on one line as possible

ajinkyapatil 6y ago
10 CLS 10 is always CLS
Starwatcher2001 6y ago
There was a bug in the TRS-80 basic (which was indeed Microsoft). It had an "on x goto" command that allowed the program to move to different lines depending on the value of a variable: ON X GOTO 200,300,400,500 depending if x=1, x=2,x=3... They'd obviously used the same parser for the standard "If a=1 then goto 200" construct, which allowed an undocumented shortcut of "If a=1, 200" which a few people noticed and started using. However, a later model fixed this, which broke a number of programs.
- C1sc0cat 6y ago
  ooh I never worked on TRS80's - so they had a version of the Arithmetic IF :-) I could have Told BillG that was bad idea back when I was 19
  - ddingus 6y ago
    x = x + (x < 5) :D No If needed. Atari Basic would allow crazy things like: 10 Goto ((x < 5)*100) + 50 Goes to either line 50 or 150, depending on the comparison result being 1, or 0) Or... Goto (100*x) Faster On goto with no checking, lol. Bill Gates was not involved with the original Atari Basic. That could be purchased on a cartridge for running MS Basic programs.
    - int_19h 6y ago
      Did Atari BASIC use 1 for TRUE? Most BASICs used -1 (i.e. all bits 1), because this allowed the same operators to work for both bitwise and Boolean logic, in the absence of a dedicated Boolean data type.
      - ddingus 6y ago
        https://atariwiki.org/wiki/Wiki.jsp?page=Boolean%20Logic%20in%20BASIC https://atariwiki.org/wiki/Wiki.jsp?page=Boolean%20Logic%20i... Yes, it used 0 and 1. And it did not contain bitwise ops. Those were quite the surprise! My first efforts were in Applesoft. Computers at school. Got an Atari machine and programmed the crap out of it. Wrote my own assembler, a few games, etc... Then I got an Apple and finding them in Applesoft was a nice surprise! Prior to that, I thought they were an assembly only thing. The trade off in the Atari basic was doing things mathematically was pretty easy and it generally, but not always, was faster. A few of us wrote fairly complex programs with basically no if statements. Kind of a fun way to think about things back then. I much prefer -1 and 0 and the bit ops, frankly. Internally, I remembered this kind of thing as "really fucking true" as in every bit better signal, or it's false!
        int_19h 6y ago
        The problem with using bit ops as logical is that they don't short circuit. Although it was unfortunately common even in languages that had proper Booleans at the time - e.g. standard Pascal didn't have it, and Turbo Pascal required a compiler directive/switch to enable it, which few even knew of. So it feels worse in retrospect than it actually was back then. On the other hand, one thing that BASIC still has to this day (in VBA) that no other language I can think of does, is bitwise equivalence (EQV) and implication (IMP) operators. Furthermore, since VBA has a Boolean data type, these operators are also available for Booleans; implication comes in handy sometimes.
- int_19h 6y ago
  This was legal in BASIC from the very first versions of the language: IF a=1 THEN 200 and when they added ON..GOTO, they basically made these two mirrored syntactically. So you could do: IF a=1 GOTO 200 ON a THEN 100,200,300 (I suspect it was simply treated as identical token?)

Theodores 6y ago

In my opinion this was not good. Basic was considered harmful and was possibly the first computer thing to be considered harmful. Line numbers, REM statements, the GOTO statement and much else had to be unlearned by anyone moving on to a professional set of programming tools. At the time we felt enabled rather than held back. But many Microsoft products were like that. The OS on a BBC micro was far ahead of DOS. Then the whole concept of the personal computer took hold even though we had already seen networking. Then the browser wars. Now we learn that Linux is to be in Windows good and proper. So we are getting there in the end.

int_19h 6y ago
At the time when BASIC only had line numbers and GOTO, it was comparable to many other popular languages out there. By 80s, when structured programming became the norm, BASIC became more structured as well, with loops and subprograms.