Questions tagged [commodore-64]
For questions about the different versions and products of the Commodore 64
270
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Obtaining a CPU execution trace on a Commodore 64 [closed]
I need to collect the execution trace of all instructions executed by the 6502 on a C64. I tried C64 Debugger, but I couldn't find any option for this. Is it possible to obtain with C64 Debugger? Are ...
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1
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How should I set CCGMS on my Commodore 64 to login to a Linux machine?
I have a Strikelink WiFi modem for the C64 (see here and here) and I can connect to a BBS without issues using CCGMS 2017 v4 and the following settings:
Baud = 9600
Modem Type = UP9600 / EZ232
For ...
- 243
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1
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126
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How to send and receive messages between modern computer and Commodore 64 via WiFi? [closed]
I want to be able to connect from my Commodore 64 to a Linux Raspberry Pi.
The ideal solution would be something like ssh that allows me to use the linux machine using the c64 as a terminal but the ...
- 243
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6
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Does lossy audio compression damage datasette data?
I grew up with the C64 and had software on cassette tapes. These days, you can find "backups" of this software all over the internet, even in mp3 format (by recording the audio signal with a ...
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Are SID Players practically almost full-fledged C64 Emulators?
There are many stand-alone audio players (and plugins for general audio players) out there for many systems that play the music of the Commodore 64 that is famous for its SID chip.
I believe many of ...
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234
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How does the VIC-II/CPU memory access work on the C64?
As a programmer I knew that on the C64 the CPU got the bus in the high phase of PHI2 and the VIC-II got it in the low phase and also stole extra high phases when required.
However, it wasn't until ...
- 263
17
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1
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Was any commercial end-user software written in PROMAL?
PROMAL is a procedural programming language from the 1980s. Its designer, Systems Management Associates, released compilers for the Commodore 64, Apple II, and IBM PC. The language and development ...
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Did Commodore ever produce gray colored Commodore 64?
The Commodore 64 was produced for a 12 years from 1982 to 1994. It had several iterations of case color, keyboard color & keyboard labels, badge etc.
Commodore was famous for using whatever parts ...
- 2,484
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230
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Commodore / Apple II GEOS Document Cross-Platform Compatibility
As I have never used Graphic Environment Operating System (GEOS) on an Apple II (only I on a Commodore 64), I have always wondered were the documents created (from programs such as GeoWrite and ...
2
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Does C64 /DMA assertion immediately disconnect the CPU from the address bus?
I have heard several claims (in the comments on this question and
answers) that asserting the D̅M̅A̅ signal on the Commodore C64
cartridge port will immediately take the CPU off the bus by deasserting ...
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192
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Timer B Interrupt occurs only once
I was following this tutorial on Commodore 64 timer interrupts and tried to replicate it (except all I was planning on doing was changing the border color.) I noticed that my interrupt only occurs ...
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0
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226
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Identify this old C64 soccer game with "speaker"
In "modern" games (Fifa 98, Fifa 2000, PES, etc) you can hear the speaker talking about the match.
This was near impossible in the C64 era, but I remember a soccer game that had a speaker ...
- 543
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0
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Identify C64 Game About Firemen
I'm searching for an old game for the C64, it was about a group of firemen. I last played it in the 1989, 32 years ago, so I do not remember it very well.
I remember only that the firemen don't want ...
- 543
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3
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How did the Commodore 64 show a picture while reading cassette?
I was watching this video just now https://www.youtube.com/watch?v=I0YmJluYb6Q&ab_channel=NostalgiaNerd on things that early home computers displayed on the screen while reading cassettes, and ...
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8
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632
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Would a multi button controller have been possible on the C64?
One thing I felt letdown the C64 for many games was the lack of multiple buttons on the joystick, meaning you had to keep the keyboard nearby, (or by your foot!) So you could press space-bar or ...
- 1,004
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Why was Carrier Command for the ZX Spectrum superior to the C64 version?
The ZX Spectrum version of Carrier Command has 3D rendering, while the Commodore 64 version, despite a greater amount of RAM, was inferior in comparison. You open the in-game map and there's Google ...
- 421
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3
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How can I store a machine language program to disk on a C64?
I know I can use LOAD "PROGRAM",8,1 to load a program in a certain spot in memory, using the first two bytes of the file on disk.
Now let's say I have used the .MON command on the Final ...
- 809
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3
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1k
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6502 ORA not updating the accumulator
Unless I'm reading the manual incorrectly, the following should produce $11 when D404 = $10 (I'm turning on the gate for voice1 which has been previously set to triangle wave %00010000/$10)
00153 ...
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2
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What is the Commodore 64C "France version" and why does it need a beefy resistor?
While perusing the schematics for the Commodore 64C (titled COMMODORE-64 B/NE) I came across a suspicious section of the power supply: The unregulated "9V" is connected to the completely ...
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260
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How to properly convert an active-low joystick routine to active-high
My last question wasn't specific enough so I'll rephrase it. I've been having trouble with programming game consoles/computers like Commodore 64 that have active-low joysticks, where the bits are all ...
- 1,478
6
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2
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Flash border color during Kernal LOAD routine
I would like to use the Kernal's LOAD routine to load a file into memory, because that seems to be the easiest way to do it. However, that LOAD call is synchronous in the sense that it returns once ...
- 2,533
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Commodore 64 sound seems to freeze at a high pitch if executed too soon after startup
I created this little sound driver for sound effects, it makes a classic "laser beam" sound you would hear in old arcade games. There's just one problem, and it's a bit of a strange one.
I ...
- 1,478
9
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1
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Confusion in the VIC-II registers
I am playing with my old C64 and fiddling with with VIC-II registers. I am using the great Programmer's Reference Guide, but there is something I don't quite get.
According to the register map, addres ...
- 809
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1
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136
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Spontaneous movement and game crashes from active-low joystick routines [closed]
I've noticed this recurring problem when I'm trying to program joysticks or buttons that are active-low (0 = pressed), like on the Commodore 64 or Game Boy Advance. Regardless of the language or ...
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2
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526
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How to wait for vBlank on Commodore 64
I'm not new to 6502 Assembly but I am new to the Commodore 64. I'm used to the NES where you have to write everything yourself, such as the NMI/RESET/IRQ vectors, etc, but from what I understand the ...
- 1,478
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How to repeat a string in C64 BASIC V2?
I would like to achieve the following: I ask for a number from the user, run a loop number times, and in each loop run, output the string like this:
-STR$
--STR$
---STR$
----STR$
-----STR$
I tried to ...
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Is this SpeedDOS chip mounted right in my C64?
I have removed a chip to reseat it, but sadly I forgot how it was placed on my C64 (breadbin).
I assume its text should be in the same direction of all the other chips on the board, but now I don't ...
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How did the C64 lockup bug and its workarounds work?
The Commodore 64 suffered from a strange bug that caused it to lock up when typing in the full-screen BASIC editor. To trigger the bug, position the cursor on the last line of the screen, type enough ...
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1k
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How can I connect my Commodore 64 to an RGB+Sync signal via SCART?
I would like to connect my Commodore 64 to my SCART switcher (Shinybow SB-5525), which is connected to a Sony PVM via RGB+Sync. I bought this cable, only to realize after getting it, it is a composite ...
- 635
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Why is my Commodore 1541-II stuck showing "Searching for $" whilst trying to load the directory?
I have a Commodore 1541-II drive. I bought this drive used (but like new) a year ago and I used it on my Commodore 64 for about 6 months, but I moved and just reconnected it to my Commodore and it no ...
- 635
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What's the deal with Commodore's RESTORE key?
Most early microcomputers provided either a dedicated key (e.g. Apple ][), keyboard combination (e.g. PC clones), or dedicated hardware button (countless examples) to "Reset" the computer. ...
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6
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4
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C128D shorted Composite and Ground
I just did a stupid thing and connected a new cable without inspecting it first. It was from a reputable seller, but has shorted pins 2 and 4.
What is the potential damage it could have caused and ...
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C64 KERNAL Loading into I/O space [duplicate]
On a Commodore 64, if I Load "*",8,1 and the file's address (first two bytes on disk) is $D000, will it load to the RAM under the I/O space?
In other words, does the KERNAL loader properly ...
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New chess engines on retro hardware
Does anyone know of any efforts to write modern chess engines for old hardware? (e.g. C64, A2e?)
I'd love to see how a pared-down Stockfish or Leela that could fit in RAM could do rating wise etc.
...
- 1,090
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Why did the VIC-20 and C64 have only 22 and 40 columns when the earlier PET had 80 column text?
When I was a kid, the "real" computers in movies looked so cool with that 80-column monochrome green text.
My first computer was a VIC-20 and it always felt very "toy-like" to me ...
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1
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Problems Connecting an Arduino Uno to a Commodore 64 Joystick Port
I have made up a DB9 connector with connections to an Arduino. I am using pins 1 to 4 on the connector. On the Arduino I have a small program which writes out a series of digital HIGH signals to the ...
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0
answers
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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 ...
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0
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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:...
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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 ...
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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 ...
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6
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1
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197
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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 ...
user16295
5
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4
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385
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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 ...
- 191
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3
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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 ...
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2
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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 ...
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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 ...
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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 ...
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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 ...
user16295
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2
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1k
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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....
user16295
0
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3
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303
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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 ...
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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 ...
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