Fixed bug in PDDemulate:

PDDemulate use to create a string of file-[1-16].dat files which individually couldn't be read by dumppattern.py (the header string is in file-01.dat and tail in file-16.dat, not very helpful). I assume since we're using a 950i (32bit) not a 930 (16bit) it isn't picking up the full 32 files correctly so doesn't cat them together at the end like it should.

I've rewritten the writeSector function to simply removed the 1-16 iteration and made all output send to file-01.dat which can be read by dumppattern.py

Fixed bug in insertpattern:

Wasn't reading the full 32bit correctly.

Provided a blank pattern created by a 950i:

img-blank contains an empty 60x150 pattern for memory slot 901. You can use this to convert a single 1bit bmp img for inserting into memory slot 901 without having to create your own blank first.