Port Number: 08h
Function: Link Assist Enable
This port controls whether the hardware link assist is enabled.
- Bit 1: 1 if link assist will generate an interrupt when a byte is received.(Link assist must be enabled)
- Bit 7: 1 if the link assist is disabled.
- Bit 1: Set to generate an interrupt when link assist receives a byte.(Link assist must be enabled)
- Bit 7: 1 to disable the link assist.
This port only exists on the 83+ SE and the 84+.
Programs which directly control the link port should disable the hardware assist.
Link Assist hardware can generate an interrupt when a byte is recieved. To enable this write 01 to port 08. When a byte recieved and an interrupt is generated bit 0 of port 9 is set. Like all interrupts this one needs to be acknowledged, do this by reading the byte from port 0A.
Credits and Contributions
- Michael Vincent: Original documentation of the link assist