```mermaid
flowchart LR 
ISR81hEntry --> b[cmp ah,81h ?]
b -->|ah!=81h| c[/ISRRETURN/]
b -->|ah=81h| b1[cmp statuscount,01h ?]
b1 -->|=01h| c
b1-->|!=01h| d{cmp al=03h ?}
d -->|al!=03h| e[call 181e]
d -->|al=03h| f[18da]
f --> g
```