Questions tagged [commodore-64]

For questions about the different versions and products of the Commodore 64

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2
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1answer
267 views

What is the file that VICE refers to as dos1541?

VICE needs a file called dos1541 if you want hardware emulation of the 1541 disk drive. What does that file contain, exactly? The 1541 seems to have two ROMs: a DOS and a KERNAL. But if I take the ...
9
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4answers
565 views

Delay loop in BASIC

Yesterday I was looking for a way to implement a delay loop on the C64. I came across this page: https://www.c64-wiki.com/wiki/TIME At the bottom of the page there is a code fragment that waits for a ...
2
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0answers
83 views

Running Codenet on a Commodore 64 Emulator

I finally managed to get basic networking stuff working on VICE, thanks to another thread on Retrocomputing. I'm now wondering how to setup a Codenet server emulation. I was able to identify four ...
1
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0answers
40 views

How to Perform RR-Net MK3 Detection on VICE Commodore 64 Emulator?

RR-Net documentation describes a detection algorithm for the MK3 model. The algorithm is supposed to reveal the last four hex digits of the MAC address. According to documentation the MAC address 28:...
2
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1answer
126 views

Modern heat sinks for Commodore C64/C128

The VIC-II and SID chips in the C64/128 are prone to over-heating and are rather expensive to replace nowadays. Some other ICs in these machines may have the same issue. An unmodified machine includes ...
8
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3answers
987 views

How to transfer files to C64 emulator quickly

I just discovered the fun of writing small programs (Basic/asm) for an emulated C64 for me. Unfortunately, I cannot get used to the emulated C64 keybord, and would like to write the programs on the ...
6
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1answer
144 views

Chaining IRQ's with BASIC & Kernal routines turned off

Having disabled BASIC and Kernal routines I set up an IRQ to run the following code when the raster line reaches 200: .irq1 inc 53280 // change border colour // lda #$ff // clear the ...
7
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2answers
712 views

Does the Commodore 64 power switch have a history of failing?

My original (1983?) Commodore 64 (brown breadbox with grey function keys) has trouble powering on. Specifically, when I flip the power switch the power LED will glow dimly and the machine fails to ...
4
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3answers
220 views

Running WarpCopy64 on an emulator

I'm interested in IP networking capabilities of the Commodore 64. I learned there is a tool called WarpCopy64 that can be used to run a simple file server on the Commodore. The server can be accessed ...
6
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2answers
902 views

Does anybody remember a database cartridge for the Commodore 64?

Decades ago I bought a database cartridge for my C64. IIRC it was a no-name brand being sold as close-out or from a bargain bin. It may have been the slowest program I ever bought. It wasn't too ...
35
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7answers
12k views

Why did Commodore 64 cartridge games disappear?

The Commodore 64 has a cartridge slot, but by the mid-eighties, cartridge games disappeared; everything was on tape or disk. Why? One answer that suggests itself is that by that time, a larger ...
6
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3answers
326 views

Is it still possible to access a BBS via dial up internet on the C64 (or other retro computers)

I was wondering if it is still possible to access any online BBS using dial up and an 80's era computer. I'm aware that some dial up internet providers still exist (eg Nippy Internet in the UK), but ...
17
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0answers
753 views

Oxford C compiler for Commodore 64

I kept one floppy from my Commodore 128 (which I used mostly in C64 mode), labelled ‘Oxford C compiler’. It is a 5.25″ floppy. Don't ask me why I kept just this one; probably because I thought I ...
3
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2answers
317 views

What high nibble values can you get when you read the 4 bit color memory on a C64/C128?

The C64 and the C128 have a memory for storing the color values of a character. The size of this memory is 1k x 4bit (2k x 4bit for the C128 which can do a double buffering), thus reading the value at ...
3
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3answers
544 views

What are quick ways to load downloaded tape images onto an unmodified 8-bit computer?

There are repositories of tape software available online, for example CPC Power for Amstrad CPC machines. What is the fastest and simplest way to load such games onto an unmodified computer, with the ...
11
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1answer
1k views

Identifying this 6502 Assembler

I found some 6502 assembler code for a Commodore 64 program that uses meta commands like #include "foobar", define the address to be assembled to via *=$1234 and define labels without a colon. ...
20
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3answers
5k views

How to detect a real Commodore 64, THEC64, or VICE emulator in software?

Some programs notice if they are run on a real Commodore 64 or an emulator. For example, this demo from 2007 stops on VICE emulator 3.2 with the message "No VIC inside". How is this done? I ...
4
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1answer
337 views

Bank switching and memory perspectives (C64)

I've been reading up on bank switching on Wiki and in particular here which contains the below nice image and have a few questions: Am I right in thinking that LOAD loads into RAM (dark grey in the ...
4
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1answer
200 views

Basic / Assembler startup code (C64)

I'm just creating my own .prg file using NCurses Hexeditor in Ubuntu which I load using load"file.prg",8 in Vice. I followed the information in this link explaining how to create a .prg file....
0
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3answers
193 views

c64 copy chars to sprite issue

How to do correct copying char to sprite ? Lets say 1st char is at $2000 second is at $2008 and copying to sprite at $2480. And with this we can copy 1 char to top left position of 1st sprite. But ...
32
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12answers
10k views

Did computer games for Commodore 64 really take “25 minutes” to load “if everything went alright”?

In the Swedish-language song "Nostalgi" by Markoolio from 2003, some of the lyrics go: My first computer had 64 kB you surfed on the water, and that's that The computer games were loaded ...
11
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1answer
2k views

Why was the 1541 so slow?

The Commodore 1541 floppy disk drive, sold for use with the 64, was notoriously slow for historical and technical reasons: Marketing insisted on compatibility with the 1540, the floppy drive sold ...
18
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6answers
1k views

Is there software that will run across multiple Commodore 8-bit machines without modification?

I noticed in some of the answers in this question that the Commodore 8-bit line apparently used a jump table at $03xx for entry into the kernel ("kernal" for the pedantic) routines. Figuring that the ...
1
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0answers
60 views

Run ca65 assembler with intermediate step of resolving macros

I would like to convert an assembler program in ca65 with macros into assembler code with resolved macros in order to carry out manual or automatic optimizations with the resulting code. Then, the ...
21
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2answers
1k 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&...
20
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2answers
2k views

How to check the C64 graphics mode used by Maniac Mansion

I have been investigating the MS-DOS port of the C64's Maniac Mansion game. The original MS-DOS port used the C64-specific character map to draw the various backgrounds in the game. I noticed that ...
6
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3answers
495 views

How do I get the size of a file on disk on the Commodore 64?

As the title, really. I'm reading a SEQ file into memory, and need to know how big it is ahead of time. I know that I can get the size in blocks by parsing the directory, although it's ugly, but the ...
11
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4answers
2k views

Is it possible to just construct a simple cable serial↔︎serial and send data from PC to C64?

I recently saw a video made by the famous "The 8 Bit Guy" about PE6502 computer. At 19:41, he successfully sent a text file from his Windows 95 laptop to the PE6502 using only a standard ...
14
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3answers
2k 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 ...
7
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1answer
257 views

Is there a possibility for a user-defined IRQ hardware vector on a Commodore 128 in C128 mode?

When an IRQ occurs, the 6502 microprocessor and its derivatives in the C64 and C128 push the status register to the stack and then load the contents of a two-byte vector at memory address $FFFE/$FFFF ...
5
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1answer
166 views

Menu in Octapolis

I have been retrogaming with Octapolis on an emulated Commodore 64. Starting up the game presents a menu offering a choice between one or two players, and between music and sound effects. But I don't ...
7
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3answers
924 views

Can the Commodore 64 display 26 rows of text?

I seem to remember some demo, or a game, which displayed 26 rows of text (that's one more than the usual text mode resolution of 40x25). My memory of it is very hazy, but at least is corroborated by ...
10
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1answer
270 views

Rationale for almost heatsunk TO-220 packages on C64 motherboard

The TO-220 packaged VR1 regulator and Q1 transistor in the Commodore 64 motherboard (reference designators cited here from the Rev. B breadbin) are mounted in a way that suggests they were supposed to ...
9
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5answers
1k views

A game where you program a robot to fulfill missions

I'm looking for a game. Unfortunately there're only few things I remember: You had a robot. There was no way to steer it manually, so to solve a room, every step to do had to be programmed in advance ...
0
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1answer
104 views

VICE loads files slowly on Fedora 32 Linux [closed]

I lately wanted to try some of the Commodore 64 games I have kept as D64 files on my Fedora Linux system using VICE. I have lately upgraded the system from Fedora 26 to Fedora 32. After I started up ...
9
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2answers
2k views

Why does the VIC-II duplicate its registers? (C64)

After sporadically reading about the C64 and tinkering here and there for over 32 years I finally decided to get to know my C64 memory layout properly. In doing so I have a question about the VIC-II ...
4
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1answer
167 views

From what errors could Commodore's tape loader recover

The Commodore PET/VIC-20/C64 tape routines write out the leader for each file twice, and then write the data twice. While it would seem that this should allow data to be loaded more reliably, ...
6
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1answer
498 views

Putting code into two different memory areas with cc65/ca65

According to cc65 / ca65 documentation, the .org directive does not affect the placement of the code unlike with other 6502 assemblers. The docs suggest defining a memory segment with the intended ...
4
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1answer
177 views

Commodore 64 CC65 - I need help with config set up for using a data segment in Bank 3

I'm developing a game for C64 using CC65 to compile my C code to ASM. To get started quickly, I have been defining the data for my sprites in C arrays and then copying the data in those arrays to the ...
44
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3answers
6k views

How did C64 games handle music during gameplay?

On the C64 there was no threading, so how did games handle treating at the same time music and game code? Music requires exact timings, and the SID had to be instructed to change the note at the right ...
4
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1answer
265 views

Does a defacto format exist for Commodore 64 SID music?

I first learned about tracker / mod music on my Amiga in the early 1990's. I remember fooling around with Protracker, listening to mods with Intuitracker, and coming to the realization that all those ...
0
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2answers
244 views

Behaviour of commas in PRINT at a line-end

Does anyone have actual documentation on how MS/Commodore BASIC handles line wrapping in PRINT statements? I tried this in an online emulator: PRINT 1,2,3,4,5,6,7,8,9,0 In this case it wraps at the ...
10
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2answers
690 views

What pointing devices were available for C64/C128?

Apart from 1351 mouse what other official Commodore C64/C128 pointing devices were available, or notable 3rd party like Mouse Cheese. Joysticks and controllers are out of question. C64-wiki seems to ...
4
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2answers
690 views

Transforming a memory dump into something loadable

As a follow-up to this question, I now have: A memory dump of the unpacked application The start address of the application I can verify that the dump is correct by starting a new instance of Vice, ...
6
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1answer
259 views

Reconstructing uncompressed program from compressed tape image

I have a C64 program in a .t64 file. If I load it into an emulator, what I see is that it loads into a cracktro, which then proceeds to uncompress (taking several seconds at 100% speed) the original ...
6
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1answer
179 views

Could a double-sided Commodore disk be written to be used as a “flippy” on a 1541, without requiring flipping on a 1571?

Although the 1571 is capable of reading and writing both sides of a disk, accesses to the second side using the second head will be performed with the drive spinning in opposite direction from how it ...
10
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1answer
635 views

Is it possible to boot C64/C128 from floppy

When powered on 1541 reads the disk for a brief moment. Is it used to boot system from floppy? Is it possible to create a bootable commodore 64 floppy?
10
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4answers
789 views

Did any devices use the Commodore 64 joystick ports as outputs or two-way communications ports?

Looking at the schematic and explanation of how the C64 joystick ports work, it seems clear that the stick direction and button lines (JOYA0, through JOYA3 for port 1 and JOYB0, through JOYB3 for port ...
3
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2answers
391 views

How were games and programs written for the C64 in assembler in the 80s? [duplicate]

Were developers using monitors like e.g. "Supermon+64", "Merlin 64" or "Monitor$C000" and cartridges like "Final Cartridge", "Action Replay" (both of ...
15
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3answers
2k views

C64/PETSCII block graphic symbol: was there ever a logical reason for their “ASCII” codes?

You know those block graphic symbols that allows you to draw lines, corners, intersections, fine bar charts, etc. they are useful and one can do a lot of stuff, but their code arrangements always ...

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