Commodore 65

Commodore 65

Type	Home computer
Discontinued	1991 (project cancelled)
Units shipped	Estimated fewer than 200 prototypes
Operating system	Commodore BASIC 10.0
CPU	CSG CSG 4510 R3
Memory	128 KB (expandable to 8 MB)
Storage	Internal 3½″ DSDD floppy (880 KB)
Display	320×200×256; 640×200×16; 640×400×16; 1280×200×4; 1280×400×4; palette of 4096 colors
Graphics	VIC‑III (CSG 4567 R5)
Sound	Dual CSG 8580 SID chips, stereo output
Predecessor	Commodore 64
Website	N/A

The Commodore 65 (C65, aka C64DX) was a prototype 8-bit personal computer developed by Commodore Business Machines in 1990–1991. Intended as a successor to the immensely popular Commodore 64, it sought to combine enhanced graphics, sound, and disk functionality with full backward compatibility.:contentReference[oaicite:1]{index=1}

History

The project began in 1989–1990 under the leadership of Fred Bowen, Bill Gardei, Paul Lassa, Victor Andrade, and others, aiming to revive the C64 line with modernized capabilities before the company shifted focus to the Amiga. In late 1990 the C65 entered full development, but Commodore chairman Irving Gould cancelled the project in 1991 amid internal conflict and financial pressure.:contentReference[oaicite:2]{index=2}

After Commodore's liquidation in 1994, a small number of prototype units—estimated at fewer than 200—were sold to collectors.:contentReference[oaicite:3]{index=3} These rare machines have auctioned for tens of thousands of dollars, with documented sales exceeding €20,000.:contentReference[oaicite:4]{index=4}

Technical specifications

• **CPU**: CSG 4510 R3 (65CE02-based) running at 3.54 MHz
• **Memory**: 128 KB onboard RAM; expansion to ~8 MB possible via bottom flap (similar to Amiga expansion):contentReference[oaicite:5]{index=5}
• **Graphics**: CSG 4567 VIC‑III chip offering:

 * 320×200 with 256 colors  
 * 640×200 or 640×400 with 16 colors  
 * 1280×200 or 1280×400 with 4 colors  
 * Hardware blitter, DMA, and genlock support:contentReference[oaicite:6]{index=6}  

• **Sound**: Dual CSG 8580 SID chips for stereo audio:contentReference[oaicite:7]{index=7}
• **Storage**: Built-in 3½″ DSDD floppy drive (880 KB) compatible with Commodore 1581 formatting:contentReference[oaicite:8]{index=8}
• **OS/BASIC**: Commodore BASIC 10.0 with full disk and graphics support

Ports and expansion

• Two DE‑9 joystick ports
• 50‑pin expansion connector and Amiga-style RAM flap
• IEC serial port for external Commodore drives
• RGB (DE‑9F), composite video, RF, stereo audio outputs
• User port (parallel), DMA expansion, and built‑in floppy interface:contentReference[oaicite:9]{index=9}

Legacy

The Commodore 65 remained a fascinating “what-could-have-been,” gaining legendary status among retro-computing enthusiasts. With fewer than 200 known working examples, it's one of the rarest Commodore prototypes.:contentReference[oaicite:10]{index=10}

MEGA65

In 2015, the non‑profit Museum of Electronic Games & Art announced the MEGA65 project: an open-source, FPGA-based re‑creation of the C65 and its intended enhancements.:contentReference[oaicite:11]{index=11}

Key modern features include:

• HDMI video output and modern composite video support
• microSD storage, Ethernet networking, USB (keyboard/mouse), and real‑time clock
• FPGA‑implemented "45GS02" CPU core capable of up to 40.5 MHz
• Optional “attic” RAM expansion up to 8 MB and accelerated DMA controller
• Mechanical keyboard in authentic Commodore layout, functioning built-in floppy drive, and injection‑molded retro chassis:contentReference[oaicite:12]{index=12}

Initial developer kits (R3) shipped to early backers in late 2020, followed by production-ready machines in 2021. Early batches quickly sold out; as of 2024, the MEGA65 is available continuously.:contentReference[oaicite:13]{index=13}

Further reading

• Kaiser, Cameron. “Secret Weapons of Commodore: The Commodore 65.” floodgap.com, accessed 2024.:contentReference[oaicite:14]{index=14}
• Bagnall, Brian. *On the Edge: The Spectacular Rise and Fall of Commodore*. Variant Press, 2005. ISBN 0‑9738649‑0‑7
• Zimmers, Bo. “Commodore 65 Computer.” zimmers.net, accessed 2024.:contentReference[oaicite:15]{index=15}
• “The MEGA65: A Modernization…” Slashdot, 2021.:contentReference[oaicite:16]{index=16}

External links

• Secret Weapons of Commodore – C65 overview
• Official MEGA65 site
• 8‑Bit Nirvana – Commodore 65
• Hi65 emulator