diff --git a/README.md b/README.md
index 1637b74..c6511df 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ This is a clone of the Micro-SCI / Franklin floppy drive controller.
 
 v0.1 is a direct clone, reverse-engineered from a Micro-SCI board.  It was cross-checked with a Franklin-branded board, as well as the (belatedly discovered) official Franklin schematic (included in doc/service_and_schematics.pdf)
 
+Since it is a faithful clone, it requires a 2708 EPROM (or a different EPROM with a 2708 adaptor).  A board slightly revised to use a 2716/2732 is available on the 2716 git branch.
+
 Firmware images can be built via the Makefile in the firmware subdirectory.  The build framework requires cc65.
 
 ![usci](usci.png?raw=true "usci")