diff --git a/firmware/HDD/hddrvr.a65 b/firmware/HDD/hddrvr.a65
index 07613a67..13c205eb 100644
--- a/firmware/HDD/hddrvr.a65
+++ b/firmware/HDD/hddrvr.a65
@@ -284,10 +284,10 @@ GetSlotInX
 ;	A = result of hd_execute
 ; Read or write command
 ;	X = Slot# << 4
-;   Y = command
+;	Y = command
 ; Status command
-;   X = low byte of disk size
-;   Y = high byte of disk size
+;	X = low byte of disk size
+;	Y = high byte of disk size
 cmdproc
  php
 
diff --git a/source/Harddisk.cpp b/source/Harddisk.cpp
index 1add0014..5cbb7fce 100644
--- a/source/Harddisk.cpp
+++ b/source/Harddisk.cpp
@@ -711,8 +711,8 @@ BYTE __stdcall HarddiskInterfaceCard::IOWrite(WORD pc, WORD addr, BYTE bWrite, B
 	case 0x0:	// r/o: status
 	case 0x1:	// r/o: execute
 	case 0x8:	// r/o: legacy next-data port
-	case 0x9:   // r/o: low byte of image size
-	case 0xa:   // r/o: high byte of image size
+	case 0x9:	// r/o: low byte of image size
+	case 0xa:	// r/o: high byte of image size
 		// Writing to these 5 read-only registers is a no-op.
 		// NB. Don't change m_status_next, as UpdateLightStatus() has a huge performance cost!
 		// Firmware has a busy-wait loop doing "rol hd_status,x"