phloppy_0

phloppy_0 is a Commodore Amiga floppy drive emulator. It emulates four drives (DF0:, DF1:, DF2:, DF3:) and is controlled through WiFi by an Android or a PC application.

DF0: - DF3: interoperation

The device is connected between the Amiga motherboard and the internal floppy drive (DF0:). When a floppy image is inserted in the virtual DF0: the physical drive input signals SEL0 and MTR0 are inactive. When there is no floppy image in the virtual DF0: the SEL0 and MTR0 signals are passed from the Amiga motherboard through the emulator to the physical drive.

When there are DF1: - DF3: physical drives connected to the Amiga, inserting a floppy image in any of the virtual DF1: - DF3: will result in malfunction of the drive.

Supported floppy image formats

Two floppy image formats are supported:

• ADF (Amiga Disk File), 880 kB
• raw MFM - 12668 bytes per track, 160 tracks per disk

Hardware

Main hardware components:

• STM32F446 - Cortex-M4 microcontroller; core of the emulator
• SDRAM, 8 MB; used for keeping floppy image contents
• ESP12-E - ESP8266 based WiFi module; provides WiFi hotspot to allow connection of a controlling application
• XC9272XL CPLD & two 8-channel open-drain buffers - interface between the microcontroller and the Amiga motherboard

On-board connectors:

• micro USB - for flashing the microcontroller
• SWD - for flashing/debugging the microcontroller
• JTAG - for flashing the CPLD
• UART (3.3 V) - for flashing the ESP8266
• power input - from the Amiga motherboard
• power output - to the physical floppy drive
• SEL2, SEL3 - input for the appropriate floppy selection signals
• male 34-pin pinheader - for connecting through a ribbon cable with the Amiga motherboard; for A600 the cable should be around 155 mm long
• female 34-pin pinheader - for connecting directly to the physical floppy drive

LEDs:

• green - indicates SDRAM active
• yellow - indicates read operation in progress
• red - indicates communication with the controlling application in progress
• blue - indicates write buffer is not empty (turn on the controlling application to write the buffer to the persistent memory)

In idle mode the device consumes around 170 mA. When the SDRAM is in active mode the current consumption is around 185 mA.

Software

Software components:

• android/ - Android control application sources
• cpld/ - CPLD design files
• output/ - APK, JED, Gerbers, microcontroller firmware
• pc/ - PC control application sources
• uc/ - microcontroller firmware sources
• wifi/ - ESP8266 source files

The Android application requires SDK level 15 and works at least on Android 4.0.3 and 8.0.0.

The WiFi hotspot parameters are stored in the STM32 microcontroller and read by ESP8266 during initialization. The parameters can be changed in source code or after compilation in the microcontroller firmware image file.

License

The project is licensed under GPL-3.0 license. See LICENSE for more information. Parts of the project are covered by other licenses (see appropriate files for details):

• ESP8266 SPI driver by David Ogilvy (MetalPhreak)
• CMSIS header files by ARM LIMITED
• STM32 header files by STMicroelectronics