X ROM Card by Audio Computers 
from SOLIDISK Technology Limited in Essex England.

Multi function card/module for a sinclair ZX81 (or timex sinclair TS1000) that will:

* Run a program from an EPROM - instructions describe how to initiate the program run from EPROM
* Burn a program to an EPROM - Instructions say up to 8K EPROM and describe how to burn an EPROM
* Attach a printer to the ZX81/TS1000 - This is a centronics interface.  Instructions mention an Epson MX.
 
It has a 9V battery connector to which the user would hook 3 9V batteries in series to provide the 25V (27V in that case) needed to burn an EPROM.