E64

General Description

E64 is a computer system that runs on macOS and linux. It's mainly inspired by the Commodore 64, Amiga 500 and Atari ST.

• Motorola 68EC020 cpu connected to 16mb BLITTER shared video ram.
• BLITTER/VIDEO chip with a resolution of 640x400 pixels, a palette of 4096 colors (12bit) running at 60Hz, alpha blending capabilities and 16mb video ram. After screen refresh, it can raise IRQ's.
• Sound:
  • Four SID chips (MOS 6581). Each individual SID chip runs at 985248Hz for the same pitch as the chips in the original C64 pal version. Emulation is achieved with the excellent reSID library by Dag Lem. Registers are remapped to enable big endian systems.
  • Four Analog Sound Devices capable of pure sinusoidal sound next to all common other sound waves.
  • Stereo mixing capabilities for all components.
• Eight independent and programmable timers connected to IRQ.

Screenshots

Below the startup screen with command m c80 cff that inspects a piece of SID io memory.

The second screenshot shows debug mode after pressing F9. The system is frozen and can be run step by step.

Usage

Command line arguments

• -cr makes executable look for a custom rom in settings directory

Keyboard Shortcuts

• ALT+Q quits application
• ALT+W start/stop wav file output to settings directory
• ALT+R resets the system
• ALT+B switches between nearest pixel and bilinear filtering mode
• ALT+S changes intensity of embedded scanlines
• ALT+F switches between fullscreen and window
• F1 Executes 1 instruction (debug mode)
• F2 Executes 8 instructions (debug mode)
• F3 Executes 64 instructions (debug mode)
• F4 Toggles between full disassembly and hex (debug mode)
• F9 switches between normal and debug mode
• F10 switches stats on/off

Debug Mode

Technical Specifications

BLITTER

SID Chips

For the big endian mapping, see picture below. It is adapted from the original Commodore datasheet.

TIMERS

Memory Map

• 0x000000-0x000007 ISP and reset vector ROM mirror (8 bytes)
• 0x000008-0x0003ff system RAM vectors (1016 bytes)
• 0x000400-0x0007ff kernel RAM (1kb)
• 0x000800-0x000fff IO area (2kb)
• 0x001000-0x00ffff kernel RAM + supervisor stack (60kb)
• 0x010000-0x01ffff blit descriptors (64kb)
• 0x020000-0x03ffff kernel ROM (128kb)
• 0x040000-0x04ffff c64 characters (2x32kb)
• 0x050000-0x05ffff amiga characters (64kb)
• 0x060000-0x0fffff heap RAM (640kb)
• 0x100000-0x1fffff user RAM + user stack (1mb)
• 0x200000-0x3fffff blitter tile RAM (2mb)
• 0x400000-0x5fffff blitter foreground color RAM (2mb)
• 0x600000-0x7fffff blitter background color RAM (2mb)
• 0x800000-0xffffff blitter pixel RAM (8mb)

Compiling

macOS

• Install Xcode
• Install the SDL2 framework development library to /Library/Frameworks
• Open the Xcode project in the ./E64 folder and build the application

Ubuntu Linux / Debian

Run the following commands in a terminal to make a debug build:

$ sudo apt install build-essential cmake git libsdl2-dev
$ git clone https://github.com/elmerucr/E64
$ cd E64 && mkdir Debug && cd Debug
$ cmake -DCMAKE_BUILD_TYPE=Debug ..
$ make

Finally, to run the application from the build directory:

$ ./E64

Websites and Projects of Interest

• CCS64 - A Commodore 64 Emulator by Per Håkan Sundell.
• Commander X16 - The Commander X16 is a modern 8-bit computer currently in active development. It is the brainchild of David "the 8 Bit Guy" Murray.
• Commander X16 emulator - Software version of Commander X16.
• Hatari - Hatari is an Atari ST/STE/TT/Falcon emulator.
• lib65ce02 - CSG65CE02 emulator written in C.
• MC6809 - MC6809 cpu emulator written in C++.
• Mega65 - The 21st century realization of the C65 heritage.
• Moira - Motorola 68000 cpu emulator written in C++ by Dirk W. Hoffmann.
• reSID - ReSID is a Commodore 6581 or 8580 Sound Interface Device emulator by Dag Lem.
• SDL Simple DirectMedia Layer - A cross-platform development library by Sam Lantinga designed to provide low level access to audio, keyboard, mouse, joystick, and graphics hardware.
• stb - single-file public domain (or MIT licensed) libraries for C/C++
• vAmiga - An Amiga 500, 1000, or 2000 on your Apple Macintosh by Dirk W. Hoffmann.
• VICE - The Versatile Commodore Emulator.
• VirtualC64 - A Commodore 64 on your Apple Macintosh by Dirk W. Hoffmann.
• visual6502 - Visual Transistor-level Simulation of the 6502 CPU and other chips.

MIT License

Copyright (c) 2023 elmerucr

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.