Modern IC replacements for retro computers by Jani Laatikainen


J-CIA64 Available

Product
FPGA replacement for MOS 6526 & 8521 CIAs.

Complete logic and all features of the original IC's implemented.

Some tested hardware: WifiModem, Ultimate-II+, SD2IEC, Pi1541, TapeCart, 1531-mouse, all original C64 mainboards, SX-64, EVO64, Commodore 128, 1570 & 1571 drives.

More info.

J-CPU64 Available

Product
Replaces MOS 6510 or 8500 CPU / processor in Commodore 64 / SX-64

Complete logic and all features of the original IC implemented, including illegal opcodes.

More info.

J-VIC Not actively developed

Product
Replacement for C64 / SX-64 VIC-II video chip
(6569, 8565, 6567, 8562)

About 90% complete, not currently actively developed, but project is not abandoned.

More info.

J-CPU264 Available

Product
FPGA replacement for MOS 7501 & 8501 CPUs in Commodore 264-series computers.

Complete logic and features implemented, including illegal opcodes.

Tested on C16, C116 and Plus/4

Lots of demanding demos and games tested, no known compatibility problems.

Some tested hardware: pi1541, Ultimate II+, TCBM2SD, real 1551 Drive, 1531 Datassette.

J-CPU02 In development

Product
6502 & SALLY CPU replacement

Works as a replacement for 6502 CPU and Atari Sally CPU (sometimes referred as 6502C)

Some already tested systems and devices include: VIC-20, Atari 600XL, Atari 800XL, Atari XE GS, Atari 130XE, Micro-Professor II, Salora Manager, 1541 Disk Drive

J-CIA500 In development

Product
Replacement for 8520 CIA (DIP40-version) used Commodore Amiga 500, 1000, 2000, 3000, CDTV and Commodore 1581 disk drive.

Work in progress...

J-CPU128 In development

Product
8502 CPU replacement for Commodore 128.

Complete logic and features implemented, including illegal opcodes.

Already tested with a lot of software and harware. Works in C64 & C128 -mode.

J-CPU07 In development

Product
Replacement for 6507 (CO10745) CPU used in Atari devices.

Complete logic and features implemented, including illegal opcodes.

Works as a CPU replacement for Atari 2600 & 2600jr (not "one chip" -version), Coleco Gemini, Atari 810 and 1050 disk drives and 850 Serial & Parallel interface.

So far tested on several different version Atari 2600 consoles and over 100 original cartridges. No compatibility issues found.

J-CPU04 Planned

Replacement for 6504 CPU used for example in Commodore 2040, 3040 and 4040 disk drives.

J-CPU09 Planned

Replacement for 6509 CPU used in CBM II -series computers.

J-PLA In production

Product
C64 PLA replacement.

New version of well known replacement with same compatibility as before.

Replaces the following original C64/SX-64 PLAs: 82S100, 93459PC, 7700, 8700, 906114-01, 251064-01.

Compatible (and tested) with 251102(SX-64), 326298, KU-14194HB, 250407, 250425 and 250466 -mainboards. NTSC and PAL -versions.
250469 uses different kind of PLA, this replacement is not compatible with 250469.

J-SRAM Ready (not currently available)

Product
C64 RAM replacement for 250466 and 250469.




Finland 2020-2025 Jani Laatikainen