Modern replacements for the DS1216 SmartWatch variants.
Status: Version 1.0 built, tested and working. Version 1.1 (minor changes) untested.
A replacement for the DS1216-E. This SmartWatch is for use on a BIOS or exapansion ROM socket. It is typically placed in between an existing BIOS ROM and its socket.
This clock is compatible with Y2K and current dates when used with this software availalbe here: https://www.dropbox.com/s/kctqpwzjxgymfz9/smwy2k.zip?dl=0 or here: ftp://ftp.oldskool.org/pub/tvdog/tandy1000/utilities/smwy2k.zip
Status: Untested.
A replacement for the ATD-20 clock. This is used in ATD exansion boards for the Tandy 1000 computers such as the T512CLK-A1. It is believed that the ATD-20 is, or is compatible with, the DS1216-B/C SmartWatch. However, the ATD-20 does not allow, nor require, a BIOS rom to be fitted to the top of the module.
A DS1216-C has been tested in a T512CLK-A1 and works fine. If purchasing an original DS1216-C today, it may be necessary to retrofit a battery replacement. Google "DS1216 battery replacement".
Software for the ATD-20 (or DS1216-C) located in a T512CLK-A1 is available from here: http://www.minuszerodegrees.net/rtc/rtc.htm . It seems to work correctly with current dates.