diff --git a/libs/ACSVM/include/CAPI/Scope.cpp b/libs/ACSVM/include/CAPI/Scope.cpp
index e67a98dc6..f903704bd 100644
--- a/libs/ACSVM/include/CAPI/Scope.cpp
+++ b/libs/ACSVM/include/CAPI/Scope.cpp
@@ -300,6 +300,15 @@ bool ACSVM_MapScope_ScriptStop(ACSVM_MapScope *scope,
       ->scriptStop(name, {id.global, id.hub, id.map});
 }
 
+//
+// ACSVM_MapScope_GetString
+//
+ACSVM_String *ACSVM_MapScope_GetString(ACSVM_MapScope *scope, ACSVM::Word idx)
+{
+   return reinterpret_cast<ACSVM_String *>(
+      reinterpret_cast<ACSVM::MapScope *>(scope)->getString(idx));
+}
+
 //
 // ACSVM_MapScope_SetActive
 //
diff --git a/libs/ACSVM/include/CAPI/Scope.h b/libs/ACSVM/include/CAPI/Scope.h
index a7e857ae0..683f0388f 100644
--- a/libs/ACSVM/include/CAPI/Scope.h
+++ b/libs/ACSVM/include/CAPI/Scope.h
@@ -98,6 +98,8 @@ ACSVM_Word ACSVM_MapScope_ScriptStartTypeForced(ACSVM_MapScope *scope,
 bool ACSVM_MapScope_ScriptStop(ACSVM_MapScope *scope,
    ACSVM_ScriptName name, ACSVM_ScopeID id);
 
+ACSVM_String *ACSVM_MapScope_GetString(ACSVM_MapScope *scope, ACSVM_Word idx);
+
 void ACSVM_MapScope_SetActive(ACSVM_MapScope *scope, bool active);
 
 ACSVM_Array *ACSVM_ModuleScope_GetModArr (ACSVM_ModuleScope       *scope, ACSVM_Word idx);
diff --git a/libs/ACSVM/lib/libacsvm-capi.dll.a b/libs/ACSVM/lib/libacsvm-capi.dll.a
index 83f1e671e..00609ebda 100644
Binary files a/libs/ACSVM/lib/libacsvm-capi.dll.a and b/libs/ACSVM/lib/libacsvm-capi.dll.a differ
diff --git a/src/k_acs-func.c b/src/k_acs-func.c
index 094fb4d17..4fc18d581 100644
--- a/src/k_acs-func.c
+++ b/src/k_acs-func.c
@@ -23,6 +23,10 @@
 #include "m_random.h"
 #include "g_game.h"
 #include "d_player.h"
+#include "r_defs.h"
+#include "r_state.h"
+#include "p_polyobj.h"
+#include "taglist.h"
 
 /*--------------------------------------------------
 	bool ACS_CF_Random(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
@@ -31,10 +35,15 @@
 --------------------------------------------------*/
 bool ACS_CF_Random(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
 {
+	INT32 low = 0;
+	INT32 high = 0;
+
 	(void)argC;
 
-	CONS_Printf("RANDOM %d thru %d\n", argV[0], argV[1]);
-	ACSVM_Thread_DataStk_Push(thread, P_RandomRange(PR_ACS, argV[0], argV[1]));
+	low = (INT32)argV[0];
+	high = (INT32)argV[1];
+
+	ACSVM_Thread_DataStk_Push(thread, P_RandomRange(PR_ACS, low, high));
 	return false;
 }
 
@@ -78,6 +87,68 @@ bool ACS_CF_PolyWait(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word ar
 	return true; // Execution interrupted
 }
 
+/*--------------------------------------------------
+	bool ACS_CF_ChangeFloor(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
+
+		Changes a floor texture.
+--------------------------------------------------*/
+bool ACS_CF_ChangeFloor(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
+{
+	ACSVM_MapScope *map = NULL;
+	ACSVM_String *str = NULL;
+	const char *texName = NULL;
+
+	INT32 secnum = -1;
+	INT32 tag = 0;
+
+	(void)argC;
+
+	tag = argV[0];
+
+	map = ACSVM_Thread_GetScopeMap(thread);
+	str = ACSVM_MapScope_GetString(map, argV[1]);
+	texName = ACSVM_String_GetStr(str);
+
+	TAG_ITER_SECTORS(tag, secnum)
+	{
+		sector_t *sec = &sectors[secnum];
+		sec->floorpic = P_AddLevelFlatRuntime(texName);
+	}
+
+	return false;
+}
+
+/*--------------------------------------------------
+	bool ACS_CF_ChangeCeiling(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
+
+		Changes a ceiling texture.
+--------------------------------------------------*/
+bool ACS_CF_ChangeCeiling(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
+{
+	ACSVM_MapScope *map = NULL;
+	ACSVM_String *str = NULL;
+	const char *texName = NULL;
+
+	INT32 secnum = -1;
+	INT32 tag = 0;
+
+	(void)argC;
+
+	tag = argV[0];
+
+	map = ACSVM_Thread_GetScopeMap(thread);
+	str = ACSVM_MapScope_GetString(map, argV[1]);
+	texName = ACSVM_String_GetStr(str);
+
+	TAG_ITER_SECTORS(tag, secnum)
+	{
+		sector_t *sec = &sectors[secnum];
+		sec->ceilingpic = P_AddLevelFlatRuntime(texName);
+	}
+
+	return false;
+}
+
 /*--------------------------------------------------
 	bool ACS_CF_EndPrint(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC)
 
diff --git a/src/k_acs.c b/src/k_acs.c
index fd4e18601..def8a5db6 100644
--- a/src/k_acs.c
+++ b/src/k_acs.c
@@ -151,7 +151,7 @@ static void ACS_EnvThreadKilled(ACSVM_Environment const *env, ACSVM_Thread *thre
 /*--------------------------------------------------
 	static void ACS_AddCodeDataCallFunc(
 		ACSVM_Environment *env, ACSVM_Word code,
-		char const *args, ACSVM_Word stack, ACSVM_Word func)
+		char const *args, ACSVM_Word argc, ACSVM_CallFunc func)
 
 		Shortcut function to simplify adding
 		CallFuncs. These are for code data ones;
@@ -172,13 +172,13 @@ static void ACS_EnvThreadKilled(ACSVM_Environment const *env, ACSVM_Thread *thre
 --------------------------------------------------*/
 static inline void ACS_AddCodeDataCallFunc(ACSVM_Environment *env, ACSVM_Word code, char const *args, ACSVM_Word argc, ACSVM_CallFunc func)
 {
+	ACSVM_Word funcId = ACSVM_Environment_AddCallFunc(env, func);
+	ACSVM_Code tCode = (argc != 0 ? ACSVM_Code_CallFunc : ACSVM_Code_CallFunc_Lit);
+
 	ACSVM_Environment_AddCodeDataACS0(
-		env,
-		code,
-		args,
-		((argc > 0) ? ACSVM_Code_CallFunc_Lit : ACSVM_Code_CallFunc),
-		argc,
-		ACSVM_Environment_AddCallFunc(env, func)
+		env, code,
+		args, tCode, argc,
+		funcId
 	);
 }
 
@@ -216,6 +216,10 @@ static void ACS_EnvConstruct(ACSVM_Environment *env)
 	ACS_AddCodeDataCallFunc(env,   62, "W",       0, ACS_CF_TagWait);
 	ACS_AddCodeDataCallFunc(env,   63, "",        1, ACS_CF_PolyWait);
 	ACS_AddCodeDataCallFunc(env,   64, "W",       0, ACS_CF_PolyWait);
+	ACS_AddCodeDataCallFunc(env,   65, "",        2, ACS_CF_ChangeFloor);
+	ACS_AddCodeDataCallFunc(env,   66, "WWS",     0, ACS_CF_ChangeFloor);
+	ACS_AddCodeDataCallFunc(env,   67, "",        2, ACS_CF_ChangeCeiling);
+	ACS_AddCodeDataCallFunc(env,   68, "WWS",     0, ACS_CF_ChangeCeiling);
 	// 69 to 79: Implemented by ACSVM
 
 	// 81 to 82: Implemented by ACSVM
diff --git a/src/k_acs.h b/src/k_acs.h
index ecd829ba9..cf9ad0555 100644
--- a/src/k_acs.h
+++ b/src/k_acs.h
@@ -129,6 +129,8 @@ void ACS_Tick(void);
 bool ACS_CF_Random(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
 bool ACS_CF_TagWait(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
 bool ACS_CF_PolyWait(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
+bool ACS_CF_ChangeFloor(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
+bool ACS_CF_ChangeCeiling(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
 bool ACS_CF_EndPrint(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
 bool ACS_CF_PlayerCount(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);
 bool ACS_CF_GameType(ACSVM_Thread *thread, ACSVM_Word const *argV, ACSVM_Word argC);