Yaay . Got the BBC B running on my Blackice as well.
I did not have a VGA converter, so as a first step I simply tried to upload the code using dfu-util. That worked fine: but set all the switches to OFF (DOWN), don't forget the jumper. And on a Macbook, use this to program it:
dfu-util -d 0483:df11 -s 0x08000000 -D icebootbeeb.raw --alt 0 -t 1024
As I had no VGA converter, I tested it by long-pressing S4 to see if the blue led would come on. Well, that worked, so I figured that the programming went right. And then I went on to hack a VGA converter. It just uses resistors.
Well, surprise, I got output on my monitor! My monitor is an old laptop LCD screen with a V.59 converter board. And that works great for old game computers and anything with sloppy video signals. Picture works, but it's just slightly unstable. I'll post a schematic a little later.
So next was to hack a PS/2 adapter. And that was a bit more troublesome. The only keyboard that I have is an old 'Mind' clicktey-click keyboard from beginning if the 90's. And it just wouldn't work at 3v3. After long thinking, I read the above comment about the Data and Clock lines being driven open-collector to ground. So I figured that I can simply tie the keyboards VCC to 5V, and keep the rest as it is. Per line a 120ohm resistor in series, and a 2k7 resistor pullup to 3v3. Works great, keys are being recognised fine, and nothing is being fried.
So that's it. Now I have to understand how this BBC B computer works. I never had one myself.
I'll post some pics as soon as I know how.