diff --git a/hardware.inc b/hardware.inc
index bcb3cbe..0dddd37 100644
--- a/hardware.inc
+++ b/hardware.inc
@@ -622,10 +622,10 @@ def B_VDMA_LEN_MODE equ 7 ; on write: VRAM DMA mode [wo]
         def VDMA_LEN_MODE_GENERAL equ 0 << B_VDMA_LEN_MODE ; GDMA (general-purpose)
         def VDMA_LEN_MODE_HBLANK  equ 1 << B_VDMA_LEN_MODE ; HDMA (HBlank)
 
-def B_VDMA_LEN_BUSY equ 7 ; on read: is a VRAM DMA active?
+def B_VDMA_LEN_BUSY equ 7 ; on read: is a VRAM DMA active? (0 = yes, 1 = no) [ro]
     def VDMA_LEN_BUSY equ 1 << B_VDMA_LEN_BUSY
-        def VDMA_LEN_NO  equ 0 << B_VDMA_LEN_BUSY
-        def VDMA_LEN_YES equ 1 << B_VDMA_LEN_BUSY
+        def VDMA_LEN_ACTIVE   equ 0 << B_VDMA_LEN_BUSY
+        def VDMA_LEN_INACTIVE equ 1 << B_VDMA_LEN_BUSY
 
 def VDMA_LEN_SIZE equ %0_1111111 ; how many 16-byte blocks (minus 1) to transfer [r/w]
 
diff --git a/hardware_compat.inc b/hardware_compat.inc
index 140b481..f66d72d 100644
--- a/hardware_compat.inc
+++ b/hardware_compat.inc
@@ -255,8 +255,10 @@ def VDMA_LENB_MODE equ B_VDMA_LEN_MODE
         def VDMA_LENF_MODE_HBL equ VDMA_LEN_MODE_HBLANK
 def VDMA_LENB_BUSY equ B_VDMA_LEN_BUSY
     def VDMA_LENF_BUSY equ VDMA_LEN_BUSY
-        def VDMA_LENF_NO  equ VDMA_LEN_NO
-        def VDMA_LENF_YES equ VDMA_LEN_YES
+        def VDMA_LENF_NO  equ VDMA_LEN_ACTIVE
+        def VDMA_LENF_YES equ VDMA_LEN_INACTIVE
+        def VDMA_LEN_NO  equ VDMA_LEN_ACTIVE
+        def VDMA_LEN_YES equ VDMA_LEN_INACTIVE
 def VDMA_LENB_SIZE equ VDMA_LEN_SIZE
 
 def RPF_READ   equ RP_READ