After wasting far too long faffing (and failing) with the windows flasher, I tried stm32flash on debian. Worked first time.
Install build-essentials and git with apt-get. The get the stm32flash code from here:
Run 'make' to build the code, then run:
# ./stm32flash -w ~edd/CortexAmigaFloppyEmulator/Firmware/CortexAmigaFloppyEmulator_1.04a.hex /dev/ttyUSB0
stm32flash - http://stm32flash.googlecode.com/
Using Parser : Intel HEX
Serial Config: 57600 8E1
Version : 0x22
Option 1 : 0x00
Option 2 : 0x00
Device ID : 0x0418 (Connectivity line)
- RAM : 64KiB (4096b reserved by bootloader)
- Flash : 256KiB (sector size: 2x2048)
- Option RAM : 16b
- System RAM : 18KiB
Wrote address 0x0800f49c (100.00%) Done.
Resetting device... done.
This was using this device: http://www.ebay.co.uk/itm/1910915205...84.m1439.l2649
which has the same pinout as: https://www.adafruit.com/products/954
red power, black ground, white RX into USB port, and green TX out of the USB port.
[ 735.619220] usb 5-1: Product: USB-Serial Controller
[ 735.619226] usb 5-1: Manufacturer: Prolific Technology Inc.
[ 735.621300] pl2303 5-1:1.0: pl2303 converter detected
[ 735.633356] usb 5-1: pl2303 converter now attached to ttyUSB0
Setup pictured here: http://imgur.com/a/1spsK