AppleIISd/README.md

AppleIISd

SD card based ProFile replacement for enhanced Apple IIe computers

The AppleIISd is an SD card based replaced for the ProFile harddrive. In contrast to other SD card based cards this card does not replace a Disk II drive. Data is saved directly onto the SD card, it is not via images on a FAT system, like on other cards. The SD card is read- / writable with CiderPress.

A Xilinx CPLD is used as a SPI controller and translates, together with the ROM driver, SD card data to/from the Apple IIe. The VHDL source is based on SPI65/B by André Fachat.

The assembler sources are written in Merlin-8.

Features

• up to 128MB storage space (4x 65535 blocks), currently 32MB
• ProDOS driver in ROM
• Auto boot
• Access LED

Requirements

The AppleIISd requires and has been tested on an enhanced IIe computer. The ROM code uses some 65c02 opcodes. ProDOS versions 1.1 to 2.4.1 seem to work.

TODOs

• Much more testing
• Support more than one partition
• Implement card detect and write protect sensing
• Use 7MHz clock as SPI clock
• SRAM option (may never work, though)
• Find a use for the IRQ pin
• Support other EPROMS than 2716 and 2732