Shared Projects by Tobrew

Expansion card that adds an MC68882 FPU to your Macintosh Classic II. The board has two layers to keep the PCB cost down. It offers a switchable clock source between the system clock (16 MHz, synchronous operation) and a crystal oscillator on the board (20,32, or 40 MHz, asynchronous operation depending on your crystal and FPU chip. If you just want a stock 16MHz FPU, leave off the oscillator and use a MC68882FN16A chip). If you want to overclock, use a faster FPU chip such as a MC68882FN40A, and the appropriate oscillator. It has been shown that the FPU can be overclocked up to 40MHz, but based on experience, keeping it around 25-33MHz maintains better CPU performance.

I added a pad for an optional 1206 LED and a spot for a 200ohm resistor.

Project by Marcin Dymczyk, Modifications by me

This is intended to slot in vertically into a 1/2AA battery holder seen on many Macintosh computers for the PRAM battery. It will allow the use of the less expensive, easier to find and less leaky CR2032 coin batteries. Uses BAT-HLD-001-THM battery holder from Mouser.

Turn a Maclock (a simple alarm clock inside a shockingly accurate miniature Macintosh shell) into a working Mac using a Raspberry Pi Zero. Buttons, brightness, sound, and battery all work.

The board is tested and works.

BlueSCSI provides a convenient way to use MicroSD cards as hard drives in your Vintage Macintosh or workstation.

This DB25 variant plugs right into the external port of your vintage computer such as Macintosh plus, SE, Classic, Classic II, and Color Classic.

Commodore 64 PLA replacement board using 2 Lattice GAL20V8B-25 ICs. Original Open Source Design by Daniel Mantione

Direct replacement for the 906114-01 PLA chip

Designed to be plugged into a socket, not to be soldered directly to the PCB. Works on all C64 motherboards. Works with Super Zaxxon, Epyx fast load, custom and alternative KERNALS

The GAL20V8B-25 ICs can be programmed with TL866 programmer.

The required fusemaps and more information are available here: https://www.freepascal.org/~daniel/c64pla/

Parts: GAL20V8B-25LP x 2
Male round pin header 14 pin x 2
IC socket 24 pin x 2