Ted Fried's MCL64 Is a Teensy 4.1-Powered Drop-In Upgrade for Your Commodore 64
Designed to replace the MOS Technology 6510 chip, the MCL64 can run in cycle-accurate or high-performance modes.
Vintage computing enthusiast Ted Fried has released a neat replacement for the MOS Technology 6510 processor at the heart of the Commodore 64 family of computers — taking advantage of the performance available in a Teensy 4.1 microcontroller board to offer a big speed boost to those who find teh original a little slow.
"The MCL64 is a MOS 6510 port of my MCL65+ project which is a 6502 emulator written in C running on a Teensy 4.1 which can be used as a drop-in replacement for the Commodore 64 CPU," Fried explains. "Like the MCL65+ the MCL64 6510 emulation can either be cycle accurate or it can run significantly faster than the original processor."
Released as a follow-up to the 6502, the MOS Technology 6510 processor is based known as the driving force behind the Commodore 64 family of eight-bit home computers. Running between 0.985MHz and 1.023MHz, depending on region, the processor is somewhat outdated by modern standards — which is where the MCL64's accelerated mode comes into play.
"When running in the accelerated mode it is actually faster than the practically unobtainable SuperCPU cartridge," Fried explains, referring to a processor upgrade launched by Creative Micro Designs in 1997 using the Western Design Center 64C816, "which is not surprising considering the MCL64 can locate all memory and ROM ranges inside of the Teensy and run them at 800MHz."
This isn't Fried's first drop-in accelerator for vintage hardware, by any means: Late last month we wrote about the MCL86jr, an FPGA-based accelerator board designed to replace the processor in an IBM PCjr. Like the MCL64, the board offers two operation modes: Cycle-accurate, for maximum compatibility, and a less-accurate high-speed mode running at between four and six times the performance of the original processor.
More information is available on the Microcore Labs blog, with PCB design files for the carrier board and source code available on GitHub under an unspecified open source license.