# Modified DOSBox-X serial passthrough (RIO latency options)

Drop these over `src/hardware/serialport/` in the DOSBox-X source tree
(v2026.06.02). They add two `directserial` options for the VWE RIO cockpit
board's few-millisecond ACK deadline (see ../../RIO-NOTES.md):

- `rxpollus:<us>` (50-1000) - host-port receive poll tick in microseconds
  (stock = 1000). Discovers inbound bytes sooner.
- `rxburst:<n>` (1-64) - deliver host-buffered received bytes n times faster
  than emulated wire speed (they already paid wire time on the real cable).

Usage: `serial1=directserial realport:COM1 rxpollus:100 rxburst:16`