Questions tagged [programming]
For questions about programming languages and constructs. For questions about specific languages please check for language-specific tags first, and use those instead.
2
votes
3answers
176 views
What was the DOS FAT12 720k floppy raw disk format structure?
I am looking for detailed info on the low-level floppy disk structure of an MSDOS-compatible 720k Double Sided Double Density disk. Stuff like GAP/SYNC patterns, ID and CRC Field structure, standard ...
3
votes
1answer
158 views
How was dataflow analysis performed before SSA?
If we look at something like LLVM or the GNU Compiler Collection, Dalvik and many others, their intermediate representation (IR) uses SSA (Static Single Assignment form), as part of their Data-Flow ...
30
votes
6answers
10k views
Which was the first programming language that had data types?
Machine language (and Assembly language) don't have the concept of data types, so if you want to add an int and a float variables in Assembly, you have to use the appropriate Assembly instruction that ...
1
vote
1answer
197 views
What don't I understand about this LR35902 code?
The question you are now reading is about a comment on this question, about overflow bugs in some Pokemon game. A comment on that question says:
It was Game Freak's first project. They just were ...
1
vote
5answers
368 views
Are there any old and nowadays active Operating Systems which has only BASIC Programming Language?
Some old Operating Systems I hear have only BASIC Programming Language. Are there any active and old operating systems which includes only BASIC Programming Language?
3
votes
2answers
314 views
EGA style 16 color dithering
I am trying to write a program in C# that will re-create the type of dithering used in many of the old sierra and Lucas arts games. I have looked up many different dithering algorithms and none seem ...
1
vote
1answer
162 views
How to read disk files using CBM specific functions in cc65 with proper error checking
TL:DR
What is the reason my kernel_read() function ignoring file errors?
I'm trying to understand how to work with files in cc54 using CBM specific functions. My target is Commodore 64 with 1541 ...
6
votes
3answers
575 views
First language designed to support embedding?
Some languages like Python, Lua, and Tcl are designed with the intention that you can easily embed the interpreter into some other native program. For example, many VFX applications like Nuke, Maya, ...
4
votes
1answer
430 views
Where can I find macrofun.hlp?
In the days before Visual Basic for Applications, the macro language for Microsoft Excel was called XLL. The syntax was similar to that of ordinary Excel formulas, except for two things:
Macros were ...
15
votes
2answers
2k views
First language with C-like memory management
This is a nerd question but I can’t find anything in google. So, in which programming language did the classical memory management system first be implemented?
I mean the division into value types (...
2
votes
1answer
217 views
Was there ever a home PC which ran JOVIAL?
We are having a frank exchange of views here in the office.
We were discussing the heydays of home PCs, back in the early 80s, when there were a plethora to choose from, most running some form of ...
17
votes
2answers
613 views
What's a good way to implement this “splashing water” effect on the C64?
This pillow fighting game set in Venice
depicts the two opponents fighting on a wobbly gondola on a canal. It was apparently known as "Pillow Fight" in English and as "Kissenschlacht" in German, and ...
15
votes
2answers
1k views
6502 branch offset calculation
This question expands on How does the 6502 implement its branch instructions?
I'm working on a cycle accurate VHDL implementation on an FPGA. I have much of the program logic already written, but I ...
4
votes
0answers
127 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 ...
10
votes
4answers
2k views
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?";...
3
votes
4answers
513 views
Was there ever a compiler type that was just large enough to contain a memory segment?
From this answer,
Hark back to the days of segmented 16-bit architectures for example: an array might be limited to a single segment (so a 16-bit size_t would do) BUT you could have multiple ...
13
votes
8answers
1k views
Uses for the halt instruction?
What was the halt instruction in early CPUs such as the Z80 and 8080 used for?
Here's a description of the Z80 instruction:
The HALT instruction suspends CPU operation until a interrupt or reset ...
18
votes
6answers
3k views
What caused the downfall of Pascal? [closed]
From 1985 to 1990 Borland's Turbo Pascal was at least as popular as C for DOS systems. Turbo Pascal was especially popular because of it's ground breaking BGI graphics interface while C was stalled in ...
14
votes
1answer
675 views
Fortran variable type defaults - origin
In older versions of Fortran, e.g. 77, variables did not need to be declared. If the name starts with I, J, K, L, M, or N then it would be assumed to be an INTEGER. Otherwise, it would be assumed to ...
0
votes
1answer
420 views
Is it possible to make VICE load .prg files faster?
When I load a C64 .prg with the Hoxs64 emulator, my .prg loads pretty much instantly.
But when I load the same .prg file with VICE (x64 app.prg) it takes quite a while (depends on memory map, but ...
2
votes
1answer
174 views
Is it possible to use the BRK instruction when ROM is banked out?
I used to use the BRK instruction when debugging on the C64.
However, when I bank out ROM with...
lda #$35 // Bank out kernal and basic
sta $01 // $e000-$ffff
...the BRK instruction (...
12
votes
3answers
2k views
What's a good way to implement this “fade” effect on C64
See the beginning of https://www.youtube.com/watch?v=hmfLBAtGAKk. Here's a screenshot:
It basically clears characters pixel by pixel both horizontally and vertically.
Use sprites for the pixel by ...
1
vote
2answers
412 views
Reading both keyboard and joystick with non-KERNAL code on C64
I'm implementing non-KERNAL joystick and keyboard controls for my Commodore 64 game.
I used to use the KERNAL SCNKEY routine earlier to read keyboard and it worked well with my joystick port 2 code. ...
28
votes
5answers
7k views
Why was nil defined as a reserved word in Pascal?
In Pascal, nil (the pointer value to "nothing") is a reserved word. Why wasn't it simply a predefined identifier as true and false are, for example?
This is stated in PASCAL User Manual and Report p....
34
votes
4answers
11k views
Who is credited for the creation of Assembly Language?
The C Programming Language was originally developed by Dennis Ritchie who also co-designed the Unix operating system with which development of the language was closely intertwined.
Is there a ...
25
votes
7answers
11k views
How can you run a program that is bigger than RAM?
Suppose you have a program that is 218 words long. However you are using a 16 bit machine and have 216 words of RAM. (The RAM is directly addressed by the CPU). On the other hand, you have unlimited '...
6
votes
2answers
339 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 ...
12
votes
3answers
2k views
Native C compiler for Sinclair ZX Spectrum
I am looking for a native C compiler for the Spectrum 128. I would like one which:
Has good support for the latest C standard at the time.
Is not limited to compiling ridiculously short source code.
...
5
votes
2answers
3k views
Best path to learn C64 assembly [closed]
The amount of tutorials, youtube videos, scanned books on C64 programming is overwhelming.
What materials would you recommend -- and, importantly, in what order! -- to build a path to programming my ...
2
votes
1answer
394 views
How was the first working version of Google written?
Which language and/or server software did Google use for its initial version?
28
votes
4answers
7k views
Why (historically) include the number of arguments (argc) as a parameter of main?
A comment on this answer to a StackOverflow question made me curious. According the C99 standard, section 5.1.2.2.1:
The function called at program startup is named main. The implementation ...
6
votes
2answers
413 views
Unsigned addition on the 6502
I am currently playing around with pointer and indirect addressing on the C64 and I encountered a problem with the ADC opcode.
I am trying to increment a number repeatedly and when it overflows (goes ...
13
votes
3answers
737 views
What is going on in the overscan area of Sega Genesis games?
What is going on in the overscan area of Sega Genesis games?
I noticed that different games display different things in the overscan area.
I understand this was never intended to be seen.
However,...
15
votes
3answers
3k views
Do you need to allocate memory before you use it in MS-DOS?
In modern operating systems (for example: Windows), you can't access a memory location before you allocate that memory location to your program (or else a segmentation fault will occur).
I am ...
4
votes
2answers
609 views
How hard would it be to port Amiga OS4 to x86 or ARM?
This question was raised on Facebook a few hours ago. Some say it's possible, others say impossible. What do you experts say?
6
votes
1answer
372 views
What is the title of this Macintosh programming book?
Back when Mac OS was called "System" and preemptive multitasking was a distant fantasy, I had a small collection of Macintosh programming books.
For the life of me, though, I can't remember what one ...
7
votes
1answer
217 views
Was there an interactive macro/scripting language named PAGEN?
In a BESM-6 disk image I can see bits and pieces of something that looks like a strange interactive scripting language:
[start of disk block]
<LET=P11=%X01
<IEQ=P11=%377
<LET=P11=1
<END
&...
3
votes
1answer
171 views
Simulate Repeat/Until in BASIC, and on a single line?
Is there a way to simulate a Repeat/Until loop in a BASIC language without it, and without using a GOTO statement?
For BASIC languages with command separators, can this be done on a single line ...
10
votes
2answers
782 views
Pattern matching, which language first had it
Which programming language was the first to use pattern match?
The oldest ones I know are:
Prolog 1972
ML 1973
Are there languages older that have pattern matching?
Edit:
By pattern matching I ...
28
votes
5answers
5k views
How was the C language ported to architectures with non-power-of-2 word sizes?
By the time the C language started to gain popularity outside of the PDP-11 circles (mid-1970s), mainframes with "weird" word sizes, and no capability to address individual bytes efficiently were ...
19
votes
5answers
2k views
Early Forth for personal computers
What were the earliest Forth programming language implementations for 8-bit personal computers? Was it FIG Forth? Or a predecessor? Or some other development?
Why did Forth lose its relative ...
5
votes
3answers
548 views
When were the analogs of the C operators “break” and “continue” introduced in Pascal?
When published in 1970, the Pascal language did not have a way to implement the functionality equivalent to the (future) C language operators "break" and "continue". Their convenience having been ...
13
votes
1answer
1k views
What was the first C compiler for the Mac?
When did a C compiler first become commercially available for the Apple Macintosh? And what was its name?
The only programming languages that I recall were available for the Mac at launch (January ...
11
votes
2answers
781 views
What is the origin of different styles of assembly language mnemonics?
As exemplified in answers to this question (I hope that closed questions that are linked to, don't get purged), the instruction mnemonics in early assembly languages had a 1-to-1 correspondence to the ...
12
votes
6answers
1k views
Do any mainframe emulators exist with a functional FORTRAN compiler?
Similar to this question, but generalized to any mainframe computer from before the microprocessor era, does there exist an emulator and OS for a vintage mainframe computer that will run the output ...
30
votes
3answers
10k views
Where does this esoteric Pascal operator come from?
In the documentation for an implementation of Pascal for a Soviet computer, I've encountered a very weird language extension. I'll try to translate it:
Branching operator (branch)
Syntax
&...
12
votes
2answers
438 views
What's the meaning of __saveds in Amiga C code?
What's the meaning of __saveds in Amiga C code?
It's applied to function prototypes, and is required for functions that are to be called by assembler code, if I understand correctly.
9
votes
3answers
2k views
What “Write your own RPG/Adventure game” books were available for 8-bit computers? [closed]
During the 70s and 80s there were a number of books about how to write your own games for 8-bit computers, usually in BASIC. Three examples of these books are How to Create Adventure Games by ...
20
votes
7answers
1k views
What implementations of BASIC had a robust flood fill operator?
When I learned BASIC on Elektronika BK, I got fascinated with the flood fill (PAINT) operator: how does it know to get to all nooks and crannies of the shape to fill? I've devised an algorithm, tried ...
14
votes
2answers
1k views
What is the “standard” way to implement KERNAL hooks on the C64?
The C64 kernel (or KERNAL as it’s known in the C64 community) routines work via a jump vector table stored in page $03xx. A common programming paradigm to create something like a "device driver" would ...
