postmaster@CUVMB.CC.COLUMBIA.EDU (02/08/90)
Regarding the previous response about modifying an existing clock, I tried this on several of the digital clocks that I own. Those clock module chips that I could find in a databook did not support 24 hr./60 Hz. The others had clock modules that were not in the databooks. According to the manufacturer (Texas Instruments, in this case), these were custom chips. Good luck. Dave (N4DSZ)