Sure... It's on this page.
The 2048 ROM is essentially exactly the same as the Spectrum except it sends an extra command to initialize the newer video properly. I left the other extra 8k Timex ROM in mine, but it's not used by the 2048 ROM. I loaded many Spectrum games and they all played fine.
It's strange - everything I found online said you have to mod the board to use EPROM, but I didn't... Mine just worked with straight swap. The documents all mention bridging pin 1 to 28, but that doesn't even make sense- pin 1 is programming voltage and isn't needed in normal use. You can use a 27256 and burn the original 16k TS2068 ROM along with the TC2048 ROM if you wanted, pull pin 27 up and put a 0v/5v switch on it to toggle. I didn't bother, because there is next to no programs available for the regular TS2068.
The only problem I have with mine is it didn't come with a power supply. I've tried a few wall-warts, and they work, but all cause various video interference issues. Perhaps the original one was better or filtered more than the junk ones in my "box of wires".
Edited by R.Cade, Tue Mar 17, 2015 6:48 AM.