This RTC ("real time clock") module can be used on a plain A1200, the ACA1220/ACA1232 accelerators (any speed grade), and on the A512/A604n memory expansions. It is software compatible with the setclock command (up to OS1.3) and with the workbench preferences of OS2.0 and higher: You can store the current time and date in the module and thus ensure that file generation/access dates are always correct on your harddrive.
The package contains the RTC module and an instruction sheet. The CR1220 battery is not included.
Pictures may vary: Starting 2018, the colour of the board is black.