ppieczul / macintosh-portable

Macintosh Portable Reverse Engineered Schematics

macintosh-portable

Attention!

The original Macintosh Portable have finally surfaced. They can be found here:

• nicpunt github
• archive.org

Introduction

This is an attempt to reverse-engineer Macintosh Portable motherboard's power distribution and management subsystem.

• The files can be opened and edited using KiCad.
• Check out the PDF releases of the schematics.
• You may take a look at my collection of vintage computers: oldcrap.org

V1M Hybrid Board

Apple Power Manager Chip (PMGR)

This is Mitsubishi M50753 Microcontroller with embedded EPROM.

Apple Sander-Wozniak Integrated Machine (SWIM)

This is a floppy controller chip, full chip spec is here. Pin 0 is in the top row of the chip, considering how the text is printed on it.

Versatile Interface Adapter (VIA)

This is G65SC22PE-2, full chip spec is here.

macintosh-portable's Issues

Resistor values

Did you read these resistor values from a properly working Hybrid? or was it an unknown one?

Because if not, then chances are those resistor values are going to be wrong, and will need cross-checked on a working example that has zero issue. The trouble with these is the Hybrid ICs go bad because the capacitor goo gets into the resistors and change their values, throwing all the setpoints off.