diff --git a/README.md b/README.md
index 72e3810..f824517 100644
--- a/README.md
+++ b/README.md
@@ -18,9 +18,9 @@ Firmware images can be built via the Makefile in the firmware subdirectory.  The
 
 ![usci](usci.png?raw=true "usci")
 
-## Jumper block
+## EPROM bank select switches (J4)
 
-* 1-2 and 3-4: controller test firmware (0x0000)
-* 1-2: 16-sector firmware (0x0100)
-* 3-4: 13-sector firmware (0x0200)
-* empty: firmware "put jumpers here" splash screen (0x0300)
+* 1:off 2:off - controller test firmware (0x0000)
+* 1:off 2: on - 16-sector firmware (0x0100)
+* 1: on 2:off - 13-sector firmware (0x0200)
+* 1: on 2: on - firmware "put jumpers here" splash screen (0x0300)