diff --git a/source/fcrd.asm b/source/fcrd.asm
index b81d012..059674c 100644
--- a/source/fcrd.asm
+++ b/source/fcrd.asm
@@ -400,12 +400,12 @@ ISR00hselfCheck:
 ;--------------------
 ISR01h:
     CMP     AL,01
-    JNZ     Fn192D
+    JNZ     ISR02h_ReleaseRD
     NOP
     NOP
-    MOV     CX,010Ah    ;Allocated 10A KB ExtMem
+    MOV     CX,010Ah    ;Allocated 266 KB ExtMem
     CALL    CheckandAllocatedExtMem
-    CMP     BX, 00h
+    CMP     BX, 00h     ;if no error, go to 18fd
     JNZ     Fn18FD
     NOP
     NOP
@@ -463,6 +463,18 @@ Fn1925:
 ;0876:1928: B402              MOV     AH,02
 ;0876:192A: EB52              JMP     197E
 ;0876:192C: 90                NOP
+;---------------
+;Fn192D
+ISR02h_ReleaseRD:
+    CMP     AL,02
+    JNZ     ISR04h
+    NOP
+    NOP
+    CALL    GUEST_Free_ExtMEM
+    POP     ES
+    PUSH    WORD PTR CS:[originES]
+    POP     ES
+    JMP     ISR_Return_197F
 ;0876:192D: 3C02              CMP     AL,02
 ;0876:192F: 750F              JNZ     1940
 ;0876:1931: 90                NOP
@@ -472,7 +484,24 @@ Fn1925:
 ;0876:1937: 2EFF360301        PUSH    WORD PTR CS:[0103]
 ;0876:193C: 07                POP     ES
 ;0876:193D: EB40              JMP     197F
+;--------------
+    NOP     ;
 ;0876:193F: 90                NOP
+;--------------
+;1940
+ISR04h:
+    NOP
+    CMP     AL,04
+    JNZ     ISR12h
+    NOP
+    NOP
+    POP     ES
+    MOV     BX,CS
+    MOV     ES,BX
+    MOV     BX,0620
+    MOV     AX,0120
+    JMP     ISR_Return_197F
+    NOP
 ;0876:1940: 3C04              CMP     AL,04
 ;0876:1942: 7510              JNZ     1954
 ;0876:1944: 90                NOP
@@ -484,6 +513,16 @@ Fn1925:
 ;0876:194E: B82001            MOV     AX,0120
 ;0876:1951: EB2C              JMP     197F
 ;0876:1953: 90                NOP
+;----------
+;1954
+ISR12h:
+    CMP     AL,12
+    JNZ     ISR10h
+    NOP
+    NOP
+    MOV     EAX,CS:[0119]
+    JMP     ISR_Return
+    NOP
 ;0876:1954: 3C12              CMP     AL,12
 ;0876:1956: 750A              JNZ     1962
 ;0876:1958: 90                NOP
@@ -491,6 +530,18 @@ Fn1925:
 ;0876:195A: 662EA11901        MOV     EAX,CS:[0119]
 ;0876:195F: EB1D              JMP     197E
 ;0876:1961: 90                NOP
+;----------------
+;1962
+ISR10h:
+    CMP     AL,10h
+    JNZ     ISR11h
+    NOP
+    NOP
+    PUSH    CX
+    CALL    16D8
+    POP     CX
+    JMP     ISR_Return
+    NOP
 ;0876:1962: 3C10              CMP     AL,10
 ;0876:1964: 750A              JNZ     1970
 ;0876:1966: 90                NOP
@@ -500,6 +551,18 @@ Fn1925:
 ;0876:196C: 59                POP     CX
 ;0876:196D: EB0F              JMP     197E
 ;0876:196F: 90                NOP
+;-------------------------------
+;1970
+ISR11h:
+    CMP     AL,11h
+    JNZ     ISR_Return
+    NOP
+    NOP
+    PUSH    BX
+    CALL    1707
+    POP     BX
+    JMP     ISR_Return
+    NOP
 ;0876:1970: 3C11              CMP     AL,11
 ;0876:1972: 750A              JNZ     197E
 ;0876:1974: 90                NOP
@@ -512,6 +575,7 @@ Fn1925:
 ;-----------------------------------------
 ISR_Return:
     POP     ES
+ISR_Return_197F:
     POP     DS
     IRET
 ;0876:197E: 07                POP     ES
@@ -555,7 +619,7 @@ Fn1993:
     PUSH    WORD PTR CS:[16D6]
     PUSH    WORD PTR CS:[16D4]
     PUSH    WORD PTR CS:[0105]
-    CALL    1A5C
+    CALL    Fn1A5C
     ADD     SP,+0E
     POP     AX
     ADD     CS:[16D4],AX
@@ -718,6 +782,7 @@ RETURN_1A5B:
     RET
 ;0876:1A5B: C3                RET
 ;------------------
+Fn1A5C:
 ;0876:1A5C: 55                PUSH    BP
 ;0876:1A5D: 8BEC              MOV     BP,SP
 ;0876:1A5F: 56                PUSH    SI