diff --git a/src/devices/bus/electron/m2105.cpp b/src/devices/bus/electron/m2105.cpp
index 81c68a80e4d..b61d2fc7104 100644
--- a/src/devices/bus/electron/m2105.cpp
+++ b/src/devices/bus/electron/m2105.cpp
@@ -153,16 +153,16 @@ uint8_t electron_m2105_device::expbus_r(address_space &space, offs_t offset, uin
 		switch (m_romsel)
 		{
 		case 0:
-			data = memregion("exp_rom")->base()[0x8000 + (offset & 0x3fff)];
+			data = m_exp_rom->base()[0x8000 + (offset & 0x3fff)];
 			break;
 		case 2:
-			data = memregion("exp_rom")->base()[0xc000 + (offset & 0x3fff)];
+			data = m_exp_rom->base()[0xc000 + (offset & 0x3fff)];
 			break;
 		case 12:
-			data = memregion("exp_rom")->base()[0x0000 + (offset & 0x3fff)];
+			data = m_exp_rom->base()[0x0000 + (offset & 0x3fff)];
 			break;
 		case 13:
-			data = memregion("exp_rom")->base()[0x4000 + (offset & 0x3fff)];
+			data = m_exp_rom->base()[0x4000 + (offset & 0x3fff)];
 			break;
 		}
 	}
diff --git a/src/devices/bus/electron/plus3.cpp b/src/devices/bus/electron/plus3.cpp
index 413bbc8ec6c..0a2be79a69e 100644
--- a/src/devices/bus/electron/plus3.cpp
+++ b/src/devices/bus/electron/plus3.cpp
@@ -66,7 +66,7 @@ ROM_END
 
 MACHINE_CONFIG_START(electron_plus3_device::device_add_mconfig)
 	/* fdc */
-	MCFG_WD1770_ADD("fdc", XTAL(16'000'000) / 2)
+	MCFG_WD1770_ADD("fdc", 16.0_MHz_XTAL / 2)
 	MCFG_FLOPPY_DRIVE_ADD_FIXED("fdc:0", electron_floppies, "35dd", floppy_formats)
 	MCFG_FLOPPY_DRIVE_SOUND(true)
 	MCFG_FLOPPY_DRIVE_ADD("fdc:1", electron_floppies, nullptr, floppy_formats)
@@ -120,7 +120,7 @@ uint8_t electron_plus3_device::expbus_r(address_space &space, offs_t offset, uin
 	{
 		if (m_romsel == 4)
 		{
-			data = memregion("exp_rom")->base()[offset & 0x3fff];
+			data = m_exp_rom->base()[offset & 0x3fff];
 		}
 	}
 	else if (offset == 0xfcc0)
diff --git a/src/devices/bus/electron/pwrjoy.cpp b/src/devices/bus/electron/pwrjoy.cpp
index 42919f378ec..2791f700372 100644
--- a/src/devices/bus/electron/pwrjoy.cpp
+++ b/src/devices/bus/electron/pwrjoy.cpp
@@ -84,7 +84,7 @@ uint8_t electron_pwrjoy_device::expbus_r(address_space &space, offs_t offset, ui
 	{
 		if (m_romsel == 15)
 		{
-			data = memregion("exp_rom")->base()[offset & 0x1fff];
+			data = m_exp_rom->base()[offset & 0x1fff];
 		}
 	}
 	else if (offset == 0xfcc0)