diff --git a/src/mame/sinclair/sprinter.cpp b/src/mame/sinclair/sprinter.cpp
index da8cc7b893b53..c44d3ed47dfce 100644
--- a/src/mame/sinclair/sprinter.cpp
+++ b/src/mame/sinclair/sprinter.cpp
@@ -578,7 +578,7 @@ u8 sprinter_state::dcp_r(offs_t offset)
 		do_mem_wait(4);
 	}
 
-	const u16 dcp_offset = (BIT(m_cnf, 3, 2) << 12) | (0 << 11) | (m_dos << 10) | (1 << 9) | (BIT(offset, 14, 2) << 7) | (BIT(offset, 13) << 4) | (BIT(offset, 7) << 3) | (offset & 0x67);
+	const u16 dcp_offset = (BIT(m_cnf, 3, 2) << 12) | (BIT(m_pn, 5) << 11) | (m_dos << 10) | (1 << 9) | (BIT(offset, 14, 2) << 7) | (BIT(offset, 13) << 4) | (BIT(offset, 7) << 3) | (offset & 0x67);
 	const u8 dcpp = m_dcp_location[dcp_offset];
 	u8 data = 0xff;
 	switch (dcpp)
@@ -700,7 +700,7 @@ void sprinter_state::dcp_w(offs_t offset, u8 data)
 	}
 	do_mem_wait(4);
 
-	const u16 dcp_offset = (BIT(m_cnf, 3, 2) << 12) | (0 << 11) | (m_dos << 10) | (0 << 9) | (BIT(offset, 14, 2) << 7) | (BIT(offset, 13) << 4) | (BIT(offset, 7) << 3) | (offset & 0x67);
+	const u16 dcp_offset = (BIT(m_cnf, 3, 2) << 12) | (BIT(m_pn, 5) << 11) | (m_dos << 10) | (0 << 9) | (BIT(offset, 14, 2) << 7) | (BIT(offset, 13) << 4) | (BIT(offset, 7) << 3) | (offset & 0x67);
 	const u8 dcpp = m_dcp_location[dcp_offset];
 	if ((dcpp >= 0xc0) && (dcpp < 0xf0))
 		m_ram_pages[dcpp - 0xc0] = data;
@@ -826,14 +826,15 @@ void sprinter_state::dcp_w(offs_t offset, u8 data)
 	case 0xc0: // 1FFD
 	case 0xc8:
 		m_sc = data;
-		if (BIT(m_cnf, 6)) m_sc = 0;      // CNF_SC_RESET
+		if (BIT(m_cnf, 6)) m_sc = 0; // CNF_SC_CLEAN
 		update_memory();
 		break;
 	case 0xc1: // 7FFD
 	case 0xc9:
 		m_pn = data;
-		if (BIT(m_cnf, 5)) m_pn &= 0xc0;  // CNF_PN[5..0]_RESET
-		if (BIT(~m_cnf, 7)) m_pn &= 0x1f; // CNF_PN[7..6]_RESET
+		if (BIT(~m_cnf, 7)) m_pn &= 0x3f; // CNF_PN[7..6]_CLEAN
+		if (BIT(~m_cnf, 7) && BIT(m_cnf, 5)) m_pn &= 0xdf; // CNF_PN[5]_CLEAN
+		if (BIT(m_cnf, 5)) m_pn &= 0xe0;  // CNF_PN[4..0]_CLEAN
 		update_memory();
 		break;
 	case 0xc2:
@@ -871,9 +872,10 @@ void sprinter_state::dcp_w(offs_t offset, u8 data)
 		if (BIT(data, 2))
 		{
 			m_cnf = data;
-			if (BIT(m_cnf, 5)) m_pn &= 0xc0;  // CNF_PN[5..0]_RESET
-			if (BIT(m_cnf, 6)) m_sc = 0;      // CNF_SC_RESET
-			if (BIT(~m_cnf, 7)) m_pn &= 0x1f; // CNF_PN[7..6]_RESET
+			if (BIT(m_cnf, 6)) m_sc = 0;      // CNF_SC_CLEAN
+			if (BIT(~m_cnf, 7)) m_pn &= 0x3f; // CNF_PN[7..6]_CLEAN
+			if (BIT(~m_cnf, 7) && BIT(m_cnf, 5)) m_pn &= 0xdf; // CNF_PN[5]_CLEAN
+			if (BIT(m_cnf, 5)) m_pn &= 0xe0;  // CNF_PN[4..0]_CLEAN
 		}
 
 		update_memory();