diff --git a/cpm/cpm.go b/cpm/cpm.go
index 1ba94a0..5fa461f 100644
--- a/cpm/cpm.go
+++ b/cpm/cpm.go
@@ -351,6 +351,11 @@ func New(logger *slog.Logger, prn string, condriver string, ccp string) (*CPM, e
 		Handler: SysCallDriveReset,
 		Fake:    true,
 	}
+	sys[45] = CPMHandler{
+		Desc:    "F_ERRMODE",
+		Handler: SysCallErrorMode,
+		Fake:    true,
+	}
 	sys[105] = CPMHandler{
 		Desc:    "T_GET",
 		Handler: SysCallTime,
diff --git a/cpm/cpm_bdos.go b/cpm/cpm_bdos.go
index e3ad8ab..4d4bb15 100644
--- a/cpm/cpm_bdos.go
+++ b/cpm/cpm_bdos.go
@@ -1519,6 +1519,12 @@ func SysCallDriveReset(cpm *CPM) error {
 	return nil
 }
 
+// SysCallErrorMode implements a NOP version of F_ERRMODE.
+func SysCallErrorMode(cpm *CPM) error {
+	return nil
+}
+
+// SysCallTime implements a NOP version of T_GET.
 func SysCallTime(cpm *CPM) error {
 	return nil
 }