Another build up for one of Exxos's ST boards, this one replaces the TOS ROMs with a small board with TOS in a much faster chip - info here: http://www.exxoshost.co.uk/atari/last/tos/index.htm
I bought this to replace the 6 Chip TOS that I removed from one of my FMs so that it could replace the TOS1.0 in an STM that I got last week, leaving the FM without an OS. So I now have an STM with 1.4 and an STFM with 1.2/1.4 switchable
0: The kit, needs soldering together.
1: Soldering the tiny SMT resistor - I'm using an aircooled VW con rod here to keep the resistor from moving while I solder it
3: Socket soldered from the underside - on mine I didn't notice that the board wasn't totally flat when I propped it in place, so the socket isn't flush with the board, still works, just looks untidy :/
4: Using a spare Dallas real time clock chip to space out the pins
5: Keeps them in line nicely.
6: Second set
7: All done, ready to fit.
8: As this FM had six chips, the 1M/254K solder pads need changing. This pic shows them in 'six chip mode'. They needed desoldering and resoldering on the 1M side. There are three (on this board anyway) the two you can see, and one near the top ROM socket.
9: fitted - you can just see the newly soldered pads as well.
10: Boots OK to 1.02
11: And swapping the jumper on the board flips it over to 1.4.
12: Shielding needed some surgery to add clearance - I didn't fancy desoldering all six ROM sockets today, maybe another time
And thats it, easy to build and fit, and speeds up the ROMs which is needed if you're going to also fit the 68K booster kits that Exxos also sells.