TransEra 641-RTC

Revision as of 01:55, 24 March 2021 by Luebben (talk | contribs) (added a furter explanation)

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

Command set

Command Description
CALL "TIMESET", T Sets the actual time. T must be a floating point number containing the count of seconds + fraction 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 the 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
CALL "CLOCK",T$ Same as "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 and 641 with identical command set. The command set differs from the command set of the unit shown on this page. So a second revision of the 641 should exist.


Pictures

Schematic

Firmware (uploaded BIN files)

Part number Location
TransEra-641-RTC-1984.bin (?)