MegaFlash for Apple IIc/IIc+

MegaFlash is an internal storage device for Apple IIc/IIc plus computer.

Feature List

• 128MB/256MB Capacity, divided into 4/8 ProDOS Drives
• 400kB RAM Disk
• ROM Disk for Disaster Recovery
• 256kB Slinky Emulation on stock firmware
• Boot Menu (Similar to ROM4X/5X)
• Control Panel
• Real Time Clock with ProDOS clock driver
• Network Time Sync (NTP Client)
• Upload/Download ProDOS Image file via WIFI and TFTP Server
• Upload/Download ProDOS Image file via XModem and USB serial port
• FPU for Applesoft BASIC
• Bug fixes of System ROM and Applesoft

A brief user guide is available for more information.

Requirement

• Apple IIc computer with Memory Expansion Card connector or
• Apple IIc plus computer

System ROM replacement is required for MegaFlash to function.

Hardware

The hardware is quite simple. All the heavy work is handled by Pi Pico. Apple 65C02 CPU only needs to copy data between RAM and Pico. Schematic is available here.

• Raspberry Pi Pico2 W
• Winbond 25Q01 NOR Flash memory
• GAL16V8 PLD for address decode
• 5V to 3.3V Logic Level Shifter

Project Directories

There are 3 software projects. There is not enough space in Apple ROM to store the Control Panel program. The program is stored in Pico flash memory.

firmware Project Directory of Apple ROM Patches
cpanel Control Panel project
pico Raspberry Pi Pico firmware
common Common header files used by all 3 projects