EVENTS macro - is type 1, gets LOCAL lock.
Calls module IEAVEVT0, entry point IGC125.
| 0 | Flag bits | ||
| 1... | .... | WAIT=YES. | |
| .1.. | .... | WAIT=NO. | |
| ..1. | .... | ECB= address. | |
| ...1 | .... | Byte 1 contains a format number | |
| .... | 1111 | Reserved. | |
| 1 | A one indicates format 1 input data. | ||
| 2-3 | Reserved. | ||