--- a/src/devices/machine/z80scc.cpp
+++ b/src/devices/machine/z80scc.cpp
@@ -1045,7 +1045,7 @@
 
 	m_uart->m_wr0_ptrbits = 0;
 
-	m_rx_fifo_sz = (m_uart->m_variant & z80scc_device::SET_ESCC) ? 8 : 3;
+	m_rx_fifo_sz = 512;   // RetroNet patch: see z80scc.h - emulation-side depth for polled receivers
 
 	m_tx_fifo_sz = (m_uart->m_variant & z80scc_device::SET_ESCC) ? 4 : 1;
 
--- a/src/devices/machine/z80scc.h
+++ b/src/devices/machine/z80scc.h
@@ -256,8 +256,10 @@
 	unsigned int m_delayed_tx_brg_change;
 
 	// receiver state
-	uint8_t m_rx_data_fifo[8];    // receive data FIFO
-	uint8_t m_rx_error_fifo[8];   // receive error FIFO
+	// RetroNet patch: widened from 8 so a POLLED receiver (no RX interrupt) survives its deaf
+	// windows under emulation; real silicon depth is 3/8 and real clients need interrupt RX.
+	uint8_t m_rx_data_fifo[512];    // receive data FIFO
+	uint8_t m_rx_error_fifo[512];   // receive error FIFO
 	uint8_t m_rx_error;       // current receive error
 	//int m_rx_fifo         // receive FIFO pointer
 	int m_rx_fifo_rp;       // receive FIFO read pointer