diff --git a/doc/syscalls.md b/doc/syscalls.md
index 8e3b80b..079d79c 100644
--- a/doc/syscalls.md
+++ b/doc/syscalls.md
@@ -11,9 +11,10 @@ register arguments they take, and what if any values they return.
 The system API is based loosely on, but not compatible with, that of
 CP/M-3 and MSX-DOS 2.
 
-Most calls return a status code in C. This code has one value,  `STATUS_OK`,
-which applies to all such calls; this value indicates that the call was
-successful. Any other value will indicate some specific error.
+Most calls return a status code in C. This code has one value, `STATUS_OK`, 
+(equal to `0x0000`) which applies to all such calls; this value indicates 
+that the call was successful. Any other value will indicate some specific 
+error.
 
 ## `0x00`: Terminate with Error Code