A couple of general questions first:
Are you using BlackIce I or BlackIce II?
Are you building your own .bin file, or the one included in github?
Icebootatm.raw should already contain a valid .bin file for BlackIce I, so sending it again is superfluous. i.e. just powering up the board should now be sufficient to load the FPGA design.
The fact that you are getting a screen full of random characters suggests the FPGA design has loaded correctly, but for some reason the 6502 has not started normally. This likely means the issue is either:
- the ROMs have (for some reason) not transferred correctly from the ARM to the external RAM
- there is a problem with the external RAM
Have you managed to use the external RAM before with any other designs? I've had a issue with the RAM not working on one board, that turned out to be a poor soldering joint on one of the FPGA pins. So this is possible.
Could you post a screen shot of the random characters?