TransEra 641-RTC

The TransEra 641 Real Time Clock ROM Pack (641-RTC) is a ROM pack for the 4051 microcomputer.

Command set

Command	Description
CALL "TIMSET", T	Sets the actual time. T must be a floating point number containing the count of seconds + fractions since the 01-01 of the current year. The resolution is 1/128 of a second.
CALL "TIMSET",T$	Sets the actual date & time. T$ must be a string in the format "MM-DD-YY HH:MM:SS". The time must be always given in 24h format.
CALL "TIME",T	Returns the actual time. The result T is a floating point number and contains the count of seconds since 01-01 of the current year. The resolution is 1/128 of a second.
CALL "TIME",T$	Returns the actual date & time. T$ contains a string in the format "WEK MM DD YY HH:MM:SS (AM/PM)". The string is formatted depending on previous calls of 24HOUR or 12HOUR. Examples: MON 07 MAR 21 4:15:20 PM MON 07 MAR 21 16:15:20 Remark: As with all 4050 RTC modules the 641-RTC is not Y2K compatible. So in this example the weekday of march, 7th, 1921 is returned.
CALL "CLOCK",T$	Same as "TIME",T$ and "TIME",T
CALL "PAUSE",T	Pauses the Program for T seconds. The parameter T must be an integer value. The maximum delay is 65535 seconds (~18hours)
CALL "TIMER",T,L	Starts an asynchronous timer with the delay T and jumps to line L when the timer is done. The maximum delay is 65535 seconds (~18hours). The timer is not retriggered automatically.
CALL "12HOUR"	Sets the format of the returned time strings to 12-hour format. This is the default time format after a power-cycle.
CALL "24HOUR"	Sets the format of the returned time strings to 24-hour format.

Curiosity

The external power supply only "protects" and updates the count of seconds within the current year. The year information is stored somewhere in the normal RAM of the 4051 and is lost after a power-cycle.

Second Revision

The manual of the TransEra 741-RTC explicitly talks about a 741-RTC and a 641-RTC with identical command set. The command set in the manual differs from the command set of the unit shown on this page. So a second hardware revision of the 641 should exist.