Micro-PET

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  2021-08-08 Micro-PET R2 released
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  2020-12-25 Micro-PET R1 released

Building a small Commodore PET clone, with advanced features has been long on my TODO list. So, when the Mini-PET came out this gave me the kick to finally start working on it. I used a CPLD as "glue"-logic and video display controller. In R1 I started out with a simple PET clone with PAL video output, and worked my way to higher frequency and more features, like VGA video output and the boot-from-SPI. This then resulted in the R2 board that is available now.

The main development is happening on github (see link left in the menu).

Features

• Commodore 3032 / 4032 / 8032 / 8296 with options menu to select at boot
• Boot-menu to select different PET versions to run
• 40 col character display
• 80 col character display
• 8296 memory map emulation
• IEEE488 interface (card edge)
• Tape connector (card edge)
• PET graphics keyboard, or alternatively a C64 keyboard
• Improved system design:
• 512k video RAM, 512k fast RAM accessible using banks on the W65816 CPU
• boot from an SPI Flash ROM
• up to 12.5 MHz mode (via configuration register)
• VGA b/w video output
• Write protection for the PET ROMs once copied to RAM
• lower 32k RAM mappable from all of the 512k fast RAM
• Improved Video output:
• Hires graphics mode (using a configuration register)
• modifyable character set
• 40/80 column display switchable
• 25/50 rows display switch
• multiple video pages mappable to $8000 video mem address

• The Micro-PET at github

Some pictures of the Micro-PET

The Micro-PET in a crystal C64-II case, built from all-new, still available parts in 2021.

The Micro-PET PCB, with visible 65816, VIA, PIAs, and the large SMD CPLD. Two memory chips with 512kB each, one for main operation, one for the video output; Ethernet and USB connections alongside the traditional IEEE488 and Tape card edge connectors.

The Micro-PET is a rather simple 65816 machine, with the CPLD being the glue for address decoding and video generation