diff --git a/src/nvr_ps2.c b/src/nvr_ps2.c
index cb0cf554c..b51aab515 100644
--- a/src/nvr_ps2.c
+++ b/src/nvr_ps2.c
@@ -68,6 +68,7 @@ static void *ps2_nvr_init(device_t *info)
         switch (romset)
         {
                 case ROM_IBMPS2_M80:  f = nvr_fopen(L"ibmps2_m80_sec.nvr", L"rb"); break;
+                case ROM_IBMPS2_M80_486:  f = nvr_fopen(L"ibmps2_m80-486_sec.nvr", L"rb"); break;
         }
         if (f)
         {
@@ -88,6 +89,7 @@ void ps2_nvr_close(void *p)
         switch (romset)
         {
                 case ROM_IBMPS2_M80:  f = nvr_fopen(L"ibmps2_m80_sec.nvr", L"wb"); break;
+                case ROM_IBMPS2_M80_486:  f = nvr_fopen(L"ibmps2_m80-486_sec.nvr", L"wb"); break;
         }
         if (f)
         {
diff --git a/src/scsi/scsi_aha154x.c b/src/scsi/scsi_aha154x.c
index 8632b05f7..e569da503 100644
--- a/src/scsi/scsi_aha154x.c
+++ b/src/scsi/scsi_aha154x.c
@@ -503,7 +503,7 @@ aha_mca_write(int port, uint8_t val, void *priv)
 
     /* Get the new assigned I/O base address. */
     dev->Base = (dev->pos_regs[3] & 7) << 8;
-    dev->Base |= ((dev->pos_regs[3] & 0xc0) ? 4 : 0);
+    dev->Base |= ((dev->pos_regs[3] & 0xc0) ? 0x34 : 0x30);
 
     /* Save the new IRQ and DMA channel values. */
     dev->Irq = (dev->pos_regs[4] & 0x07) + 8;
@@ -578,6 +578,10 @@ aha_mca_write(int port, uint8_t val, void *priv)
 		mem_mapping_enable(&dev->bios.mapping);
 		mem_mapping_set_addr(&dev->bios.mapping, dev->rom_addr, ROM_SIZE);
 	}
+
+	/* Say hello. */
+	pclog("AHA-1640: I/O=%04x, IRQ=%d, DMA=%d, BIOS @%05X, HOST ID %i\n",
+		dev->Base, dev->Irq, dev->DmaChannel, dev->rom_addr, dev->HostID);
     }
 }
 
@@ -760,6 +764,7 @@ aha_init(device_t *info)
     dev->int_geom_writable = 0;
     dev->cdrom_boot = 0;
     dev->bit32 = 0;
+    dev->lba_bios = 0;
 
     dev->ven_thread = aha_thread;
     dev->ven_cmd_is_fast = aha_cmd_is_fast;
@@ -838,6 +843,8 @@ aha_init(device_t *info)
 		dev->bios_path = L"roms/scsi/adaptec/aha1640.bin";
 		dev->fw_rev = "BB01";
 
+		dev->lba_bios = 1;
+
 		/* Enable MCA. */
 		dev->pos_regs[0] = 0x1F;	/* MCA board ID */
 		dev->pos_regs[1] = 0x0F;	
diff --git a/src/scsi/scsi_buslogic.c b/src/scsi/scsi_buslogic.c
index bf004b79c..7cca0e60e 100644
--- a/src/scsi/scsi_buslogic.c
+++ b/src/scsi/scsi_buslogic.c
@@ -1337,7 +1337,7 @@ buslogic_mca_write(int port, uint8_t val, void *priv)
     /* Get the new assigned I/O base address. */
     if (dev->pos_regs[3]) {
 	dev->Base = dev->pos_regs[3] << 8;
-	dev->Base |= ((dev->pos_regs[2] & 0x10) ? 4 : 0);
+	dev->Base |= ((dev->pos_regs[2] & 0x10) ? 0x34 : 0x30);
     } else {
 	dev->Base = 0x0000;
     }
@@ -1347,7 +1347,7 @@ buslogic_mca_write(int port, uint8_t val, void *priv)
     dev->DmaChannel = dev->pos_regs[5] & 0x0f;	
 
     /* Extract the BIOS ROM address info. */
-    if (dev->pos_regs[0] & 0xe0)  switch(dev->pos_regs[0] & 0xe0) {
+    if (dev->pos_regs[2] & 0xe0)  switch(dev->pos_regs[2] & 0xe0) {
 		case 0xe0: /* [0]=111x xxxx */
 		bl->bios_addr = 0xDC000;
 		break;
@@ -1433,6 +1433,10 @@ buslogic_mca_write(int port, uint8_t val, void *priv)
 		mem_mapping_enable(&bl->bios.mapping);
 		mem_mapping_set_addr(&bl->bios.mapping, bl->bios_addr, ROM_SIZE);
 	}
+
+	/* Say hello. */
+	pclog("BT-640A: I/O=%04x, IRQ=%d, DMA=%d, BIOS @%05X, HOST ID %i\n",
+		dev->Base, dev->Irq, dev->DmaChannel, bl->bios_addr, dev->HostID);
     }
 }
 
@@ -1490,6 +1494,7 @@ buslogic_init(device_t *info)
     dev->int_geom_writable = 1;
     dev->cdrom_boot = 0;
     dev->bit32 = 0;
+    dev->lba_bios = 0;
 
     bl->chip = info->local;
     bl->PCIBase = 0;
diff --git a/src/scsi/scsi_x54x.c b/src/scsi/scsi_x54x.c
index 72f885573..9e17e3fab 100644
--- a/src/scsi/scsi_x54x.c
+++ b/src/scsi/scsi_x54x.c
@@ -1609,12 +1609,12 @@ x54x_out(uint16_t port, uint8_t val, void *priv)
 
 				case CMD_BIOSCMD: /* execute BIOS */
 					cmd = (BIOSCMD *)dev->CmdBuf;
-					if (!(dev->bus & DEVICE_MCA)) {
+					if (!dev->lba_bios) {
 						/* 1640 uses LBA. */
 						cyl = ((cmd->u.chs.cyl & 0xff) << 8) | ((cmd->u.chs.cyl >> 8) & 0xff);
 						cmd->u.chs.cyl = cyl;
 					}
-					if (dev->bus & DEVICE_MCA) {
+					if (dev->lba_bios) {
 						/* 1640 uses LBA. */
 						x54x_log("BIOS LBA=%06lx (%lu)\n",
 							lba32_blk(cmd),
@@ -1627,7 +1627,7 @@ x54x_out(uint16_t port, uint8_t val, void *priv)
 							cmd->u.chs.head,
 							cmd->u.chs.sec);
 					}
-					dev->DataBuf[0] = x54x_bios_command(dev, dev->max_id, cmd, (dev->bus & DEVICE_MCA)?1:0);
+					dev->DataBuf[0] = x54x_bios_command(dev, dev->max_id, cmd, (dev->lba_bios)?1:0);
 					x54x_log("BIOS Completion/Status Code %x\n", dev->DataBuf[0]);
 					dev->DataReplyLeft = 1;
 					break;
diff --git a/src/scsi/scsi_x54x.h b/src/scsi/scsi_x54x.h
index cdc7b5ebf..33c926082 100644
--- a/src/scsi/scsi_x54x.h
+++ b/src/scsi/scsi_x54x.h
@@ -424,6 +424,7 @@ typedef struct {
     uint8_t	max_id;
     uint8_t	pci_slot;
     uint8_t	bit32;
+    uint8_t	lba_bios;
 
     mem_mapping_t mmio_mapping;