The EM1000 has four LED control lines -- SG, SR, EG, and EY. All lines have the same internal structure and the LEDs should be connected to these lines as shown on the schematic diagram below. Maximum load for each line is 10mA.
Further information on status LEDs can be found in Status LEDs.
Your Tibbo BASIC/C application can control red and green status LEDs, as well as up to four externally connected LED pairs through the pattern (pat.) object, which is documented in the TIDE, TiOS, Tibbo BASIC, and Tibbo C Manual.