Tag: i2c

Adds an inexpensive battery-backed real-time clock to a Commodore 64 through the user or cassette port.

The current project page provides version 1.0 software and exact wiring for three C64 connection choices. Gregory Nacu's i2c6502 source independently documents the C64 user-port PB2/PB3 implementation and DS3231 example under the MIT license. A generic RTC module, connector or pass-through board, wire, and battery are separate. Many inexpensive modules include a charging circuit intended for a rechargeable cell; follow the project's component-removal instructions before substituting a CR2032 or CR1225 primary cell. The Timo Voutilainen package does not state a hardware fabrication or software license.

Adds a software-controlled FM receiver to a Commodore 64 or 128 through the user port, with an optional real-time clock and station storage.

Protovision showed eight units in stock with a one- to two-week shipping estimate on 2026-07-29. The optional DS3231 module and its CR2032 or LIR2032 battery are not included. The seller says the supplied software is incompatible with SD2IEC and similar devices and strongly recommends an original disk drive.

Adds a software-driven I2C master interface to RC2014 and RCBus systems.

The project supplies a schematic, Gerbers, PCB design files, and links for kits and bare PCBs; an assembled version is not offered. On PCB v1.0.0, the example I2C read and write address labels are reversed: read starts at 0xA1 and write starts at 0xA0.

Experimental C64 replacement motherboard with three SID sockets, optional internal storage and sound modules, ROM switching, and extensive test points.

On 2026-07-30, UNI64 listed the bare v4 PCB at EUR 32.50 as a three-week preorder and the READY+ board at EUR 345 with a five-week order lead time. READY+ includes standard logic, the 8701, and 64 KB RAM but excludes all named Commodore-specific chips and the required 12 VDC 2 A supply with a 2.1 mm inner-diameter barrel plug. Optional Pi1541, MIDI, FM OPL2, and SSD hardware is not included. The bare page labels its feature list as Version 3 even though the product and files are v4; the linked v4 info PDF remained unreadable after the required retry under WF-071, so confirm version-specific assembly details from the supplied documentation.