diff --git a/as/k-as.py b/as/k-as.py
index 59d728a..1b86c4e 100755
--- a/as/k-as.py
+++ b/as/k-as.py
@@ -369,52 +369,6 @@ def parse_preproc(line):
 
 #-------------------------------------------------------------------------------
 
-pconds = {
-    'c':    0b00001,
-    'o':    0b00010,
-    'z':    0b00011,
-    'e':    0b00011,
-    's':    0b00100,
-
-    'pe':   0b00101,
-    'po':   0b10101,
-
-    'b':    0b00001,
-    'be':   0b00110,
-    'l':    0b00111,
-    'le':   0b01000,
-
-    'a':    0b10110,    # nbe
-    'ae':   0b10001,    # nb
-    'g':    0b11000,    # nle
-    'ge':   0b10111,    # nl
-
-    'axz':  0b01001,
-    'bxz':  0b01010,
-    'cxz':  0b01011,
-    'dxz':  0b01100,
-
-    'axnz':  0b11001,
-    'bxnz':  0b11010,
-    'cxnz':  0b11011,
-    'dxnz':  0b11100,
-}
-
-def get_cond_mask(cond, line):
-    mask = 0
-
-    if cond[0] == 'n':
-        cond = cond[1:]
-        mask = 0b10000
-    
-    if cond not in pconds:
-        print("Invalid condition suffix: {}".format(line))
-        leave(1)
-
-    return (mask | pconds[cond])
-    
-#-------------------------------------------------------------------------------
-
 fmts = {
     "r":        0b00000000,
     "m_r":      0b00100000,
@@ -456,40 +410,11 @@ def parse_instr(line):
         params = None
 
     size = 1
-
-    # Byte 2 (rep|lock|0|cond)
-    b2 = 0
-
-    if len(instr) > 2 and '.' in instr:
-        instr, suf = instr.split('.', 1)
-        
-        if len(instr) == 0:
-            print("Missing instruction name before suffixes: {}".format(line))
-
-        if len(suf) > 2 and suf[:3] == "rep":
-            if len(suf) > 3:
-                suf = suf[3:]
-
-                if len(suf) > 0 and suf[0] == '.':
-                    suf = suf[1:]
-            else:
-                suf = ''
-
-            b2 |= 1<<7  # REP
-
-        if len(suf) > 0:
-            b2 |= get_cond_mask(suf, line)
-
     instr_name = instr
     instr_args = ''
 
     if params == None or len(params) == 0:
-        if b2 == 0:
-            instrs.write("{}_0".format(instr_name))
-
-        else:
-            size += 1
-            instrs.write("%%suff {}_0 %%imm8 {}".format(instr_name, b2))
+        instrs.write("{}_0".format(instr_name))
 
         return size
 
@@ -721,19 +646,13 @@ def parse_instr(line):
 
         instr_args += word
 
-    if b2 == 0:
-        instrs.write("{} {}".format(instr_name, instr_args))
-
-    else:
-        size += 1
-        instrs.write("%%suff {} %%imm8 {} {}".format(instr_name, b2, instr_args))
+    instrs.write("{}{}".format(instr_name, instr_args))
 
     return size
 
 #-------------------------------------------------------------------------------
 
 special_syms = {
-    "%%suff",
     "%%imm8",
     "%%imm16",
     "%%imm32",
@@ -749,7 +668,6 @@ def gentext():
         data_start += (8 - data_start % 8)
 
     instrs.seek(0)
-    suff_mask = 0
 
     for _, line in enumerate(instrs):
         tok = line.strip().split()
@@ -769,9 +687,8 @@ def gentext():
                 continue
 
             if word in pinstrs:
-                idx = pinstrs.index(word) | suff_mask
+                idx = pinstrs.index(word)
                 b_text.write(idx.to_bytes(1, byteorder='little', signed=False))
-                suff_mask = 0
                 continue
 
             if word in plabels_text:
@@ -785,9 +702,7 @@ def gentext():
                 continue
 
             if word in special_syms:
-                if word == "%%suff":
-                    suff_mask = 1<<7
-                elif word == "%%imm8":
+                if word == "%%imm8":
                     lastimm = 1
                 elif word == "%%imm16":
                     lastimm = 2
diff --git a/as/regs.lst b/as/regs.lst
index 74376a0..b47bcdc 100644
--- a/as/regs.lst
+++ b/as/regs.lst
@@ -1,18 +1,10 @@
-$rzx $zero
-$cr0
-$cr1
-$cr2
-$rfx
-$rip
-$rbp
-$rsp
-
 $rax $r0
 $rbx $r1
 $rcx $r2
 $rdx $r3
 $rsi $r4
 $rdi $r5
+
 $ax0 $r6
 $ax1 $r7
 $ax2 $r8
@@ -29,6 +21,19 @@ $nx5 $r17
 $nx6 $r18
 $nx7 $r19
 $nx8 $r20
+
 $grp $r21
 $trp $r22
-$srp $r22
+$srp $r23
+
+$tmp $r24
+$rad $r25
+
+$cr0 $r26
+$cr1 $r27
+
+$rip $r28
+$rbp $r29
+$rsp $r30
+
+$zero $r31
diff --git a/ka/crt/crt.k b/ka/crt/crt.k
index 8813b0c..a6dd85b 100644
--- a/ka/crt/crt.k
+++ b/ka/crt/crt.k
@@ -5,47 +5,49 @@
 ; Limits
 ;
 
-CHAR_MIN    := 0x0000000000000080
-SHRT_MIN    := 0x0000000000008000
-INT_MIN     := 0x0000000080000000
+CHAR_MIN    := 0x80
+SHRT_MIN    := 0x8000
+INT_MIN     := 0x80000000
 LONG_MIN    := 0x8000000000000000
 
 XCHAR_MIN   := 0xFFFFFFFFFFFFFF80
 XSHRT_MIN   := 0xFFFFFFFFFFFF8000
 XINT_MIN    := 0xFFFFFFFF80000000
 
-CHAR_MAX    := 0x000000000000007F
-SHRT_MAX    := 0x0000000000007FFF
-INT_MAX     := 0x000000007FFFFFFF
+CHAR_MAX    := 0x7F
+SHRT_MAX    := 0x7FFF
+INT_MAX     := 0x7FFFFFFF
 LONG_MAX    := 0x7FFFFFFFFFFFFFFF
 
-BYTE_MAX    := 0x00000000000000FF
-WORD_MAX    := 0x000000000000FFFF
-LWORD_MAX   := 0x00000000FFFFFFFF
+BYTE_MAX    := 0xFF
+WORD_MAX    := 0xFFFF
+LWORD_MAX   := 0xFFFFFFFF
 QWORD_MAX   := 0xFFFFFFFFFFFFFFFF
 
-FILE_MAXSZ  := 0x0000000000008000
-STRLEN_MAX  := 0x000000007AFFFFFF
-FNAME_MAX   := 0x0000000000000080
+FNAME_MAX   := 0x80
+FILE_MAXSZ  := 0x8000
+STRLEN_MAX  := 0x7AFFFFFF
 
 ;
 ; Magic numbers
 ;
 
-PRN_CLEAR   := 0x000000008BF00001
-PRN_FLUSH   := 0x000000008BF00002
+PRN_CLEAR   := 0x8BF00001
+PRN_FLUSH   := 0x8BF00002
 
 ;
 ; CRT librairies
 ;
 
 include "crt/sys.k"
-include "crt/err/errno.k"
-include "crt/fmt/format.k"
-include "crt/str/string.k"
-include "crt/mem/memory.k"
-include "crt/lib/time.k"
+include "crt/str.k"
+include "crt/mem.k"
+include "crt/time.k"
 
+include "crt/fmt/ltostr.k"
+include "crt/fmt/strtol.k"
+include "crt/fmt/doprnt.k"
+include "crt/fmt/printf.k"
 abort:
     crash
 
diff --git a/ka/crt/err/errno.k b/ka/crt/err/errno.k
deleted file mode 100644
index ee3a284..0000000
--- a/ka/crt/err/errno.k
+++ /dev/null
@@ -1,7 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-EINVAL := 1
-errno = 0
-
-EOK := 0
diff --git a/ka/crt/fmt/doprnt.k b/ka/crt/fmt/doprnt.k
index f01353e..46cc890 100644
--- a/ka/crt/fmt/doprnt.k
+++ b/ka/crt/fmt/doprnt.k
@@ -15,14 +15,14 @@ doprnt:
     mov r12, ax2        ; fmt
     mov r14, ax3        ; va_list
     mov r15, ax1        ; n
-    mov r16, zero       ; return value
     mov r17, ax0        ; putc
+    nul r16             ; return value
 
 .main_loop:
     ; find '%' or null-terminator
     mov rcx, STRLEN_MAX
     mov r13, r12
-    scasb.rep.nz r13, '%'
+    scasb r13, '%'
 
     ; everything below r13 is a regular character; print it
 .print_regular:
@@ -62,7 +62,7 @@ doprnt:
     bzr r13, .nullstring
 
 .print_string:
-    mov ax0, b[r13]
+    movzx ax0, b[r13]
     bzr ax0, .main_loop
 
     inc r13, 1
@@ -107,7 +107,7 @@ doprnt:
     inc r14, 8
 
 .print_itoa_buf:
-    mov ax0, b[r13]
+    movzx ax0, b[r13]
 
     bzr ax0, .pib_end_loop
     inc r13, 1
@@ -144,8 +144,9 @@ doprnt:
 .epilogue:
     mov rax, r16
 
-    pop r17, r16, r15
-    pop r14, r13, r12
+    pop r17, r16
+    pop r15, r14
+    pop r13, r12
 
     leave
     ret
@@ -170,7 +171,7 @@ doprnt:
     jraxz .r
 
     ; yes, so artificially set n=0
-    mov r15, zero
+    nul r15
 
 .r:
     ret
diff --git a/ka/crt/fmt/format.k b/ka/crt/fmt/format.k
deleted file mode 100644
index a79e79e..0000000
--- a/ka/crt/fmt/format.k
+++ /dev/null
@@ -1,8 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-include "crt/fmt/ltostr.k"
-include "crt/fmt/strtol.k"
-include "crt/fmt/doprnt.k"
-include "crt/fmt/printf.k"
-
diff --git a/ka/crt/fmt/ltostr.k b/ka/crt/fmt/ltostr.k
index 304cd8c..dc6e3a2 100644
--- a/ka/crt/fmt/ltostr.k
+++ b/ka/crt/fmt/ltostr.k
@@ -12,7 +12,7 @@ itoa:
 ; void utoa(char *buf, int num, int base)
 ;
 utoa:
-    mov ax3, zero
+    nul ax3
     jmp ltostr
 
 ;
@@ -20,7 +20,7 @@ utoa:
 ;
 ltostr:
     mov rax, ax0
-    mov rcx, zero
+    nul rcx
 
     ; make sure base is in [2, 32]
     bltu ax2, 2, .bad
@@ -37,7 +37,7 @@ ltostr:
     shr rcx, ax1, 63        ; extract ax1 sign
     jrcxz .conv
 
-    sub ax1, zero, ax1      ; NEG if negative
+    neg ax1     ; NEG if negative
 
     ; main loop
 .conv:
@@ -68,7 +68,7 @@ ltostr:
     inc ax0, 1
 
 .cxz:
-    mov b[ax0], zero
+    nul b[ax0]
 
     call strrev2, rax
     ret
@@ -77,7 +77,6 @@ ltostr:
 ; exceptional cases
 ;
 .bad:
-    mov q[errno], EINVAL
     mov b[ax0], 0
     ret
 
diff --git a/ka/crt/fmt/printf.k b/ka/crt/fmt/printf.k
index 02a8fbd..657449b 100644
--- a/ka/crt/fmt/printf.k
+++ b/ka/crt/fmt/printf.k
@@ -6,7 +6,7 @@
 ;
 putc:
     prn ax0
-    mov rax, zero
+    nul rax
     ret
 
 ;
diff --git a/ka/crt/fmt/strtol.k b/ka/crt/fmt/strtol.k
index 9494a4d..be06c57 100644
--- a/ka/crt/fmt/strtol.k
+++ b/ka/crt/fmt/strtol.k
@@ -18,7 +18,7 @@ strtol:
 ; rdx = pointer to first invalid byte
 ;
 strtoul:
-    mov ax2, zero
+    nul ax2
     jmp strtoq
 
 ;
@@ -27,8 +27,7 @@ strtoul:
 ; guesses base when 'base'=0
 ;
 strtoq:
-    mov rax, zero
-    mov rsi, zero
+    nul rax, rsi
     mov rdx, ax0
 
     ; make sure base is in [2, 32]
@@ -158,12 +157,11 @@ strtoq:
     bzr rsi, .r
 
     ; yes
-    sub rax, zero, rax
+    neg rax
 
 .r:
     ret
 
 .bad:
-    mov q[errno], EINVAL
     ret
 
diff --git a/ka/crt/mem/memory.k b/ka/crt/mem.k
similarity index 95%
rename from ka/crt/mem/memory.k
rename to ka/crt/mem.k
index 6004199..196efc6 100644
--- a/ka/crt/mem/memory.k
+++ b/ka/crt/mem.k
@@ -24,7 +24,7 @@ memzero:
     jrcxz .r
 
 .l:
-    mov b[ax0], zero
+    nul b[ax0]
     inc ax0, 1
     loop .l
 
diff --git a/ka/crt/str.k b/ka/crt/str.k
new file mode 100644
index 0000000..0b72b2b
--- /dev/null
+++ b/ka/crt/str.k
@@ -0,0 +1,222 @@
+; The OS/K Team licenses this file to you under the MIT license.
+; See the LICENSE file in the project root for more information.
+
+;
+; int strnlen(char *, int)
+;
+strnlen:
+    mov rcx, ax1
+    scasb ax0, zero
+
+    sub rax, ax1, rcx
+    ret
+
+;
+; int strlen(char *)
+;
+strlen:
+    mov rcx, STRLEN_MAX
+    mov rdx, rcx
+    scasb ax0, zero
+
+    sub rax, rdx, rcx
+    ret
+
+;
+; void strcpy(char *, const char *)
+;
+strcpy:
+.l:
+    mov rcx, b[ax1]
+    mov b[ax0], rcx
+
+    jrcxz .r
+
+    inc ax0, 1
+    inc ax1, 1
+
+    jmp .l
+
+.r:
+    ret
+
+;
+; void strncpy(char *, const char *, int)
+;
+strncpy:
+    mov rcx, ax2
+    jrcxz .r
+
+.l:
+    mov b[ax0], b[ax1]
+
+    inc ax0, 1
+    inc ax1, 1
+
+    loop .l
+
+.r:
+    ret
+
+;
+; void strnzcpy(char *, const char *, int)
+;
+strnzcpy:
+    mov rcx, ax2
+    jrcxz .r
+
+.l:
+    mov rax, b[ax1]
+    mov b[ax0], rax
+
+    jraxz .r
+
+    inc ax0, 1
+    inc ax1, 1
+
+    loop .l
+
+.z:
+    nul b[ax0]
+
+.r:
+    ret
+
+;
+; int strcmp(const char *str1, const char *str2)
+;
+; Returns:
+;    0 if the contents of both strings are equal
+;   >0 if the first character that does not match has a greater value in str1 than in str2
+;   <0 if the first character that does not match has a lower value in str1 than in str2
+;
+strcmp:
+    nul rsi
+.l:
+    movzx rax, b[ax0+rsi]
+    movzx rdx, b[ax1+rsi]
+
+    bne rax, rdx, .r
+
+    ; both zero?
+    add rcx, rax, rdx
+    jrcxz .r
+
+    inc rsi, 1
+    jmp .l
+
+.r:
+    dec rax, rdx
+    ret
+
+;
+; int strncmp(const char *str1, const char *str2, int maxn)
+;
+strncmp:
+    mov rcx, ax2
+    jrcxz .r
+
+.l:
+    movzx rax, b[ax0]
+    movzx rdx, b[ax1]
+
+    bne rax, rdx, .r
+
+    inc ax0, 1
+    inc ax1, 1
+    loop .l
+
+.r:
+    dec rax, rdx
+    ret
+
+;
+; char *strchrnul(const char *str, int ch)
+;
+strchrnul:
+    mov rcx, STRLEN_MAX
+    scasb ax0, ax1
+
+    mov rax, ax0
+    ret
+
+;
+; char *strchr(const char *str, int ch)
+;
+strchr:
+    mov rcx, STRLEN_MAX
+    scasb ax0, ax1
+
+    bnz b[ax0], .r
+    nul rax
+    ret
+
+.r:
+    mov rax, ax0
+    ret
+
+;
+; void strrev(char *buf, const char *str)
+;
+; buf and src must NOT overlap
+;
+strrev:
+    bzr b[ax1], .z
+
+    ; save str's location
+    mov rsi, ax1
+
+    ; go to str's end, just before
+    ; the null terminator
+    mov rcx, STRLEN_MAX
+    scasb ax1, zero
+    dec ax1, 1
+
+.l:
+    ; copy, going backward though str
+    ; and forward through buf
+    mov b[ax0], b[ax1]
+
+    beq ax1, rsi, .r
+
+    inc ax0, 1
+    dec ax1, 1
+    jmp .l
+
+.r:
+    nul b[ax0+1]
+    ret
+
+.z:
+    nul b[ax0]
+    ret
+
+;
+; void strrev2(char *str)
+;
+; Inverses str
+;
+strrev2:
+    bzr b[ax0], .r
+
+    mov ax1, ax0
+
+    ; go to str's end, just before
+    ; the null terminator
+    mov rcx, STRLEN_MAX
+    scasb ax1, zero
+    dec ax1, 1
+
+    ; increase ax0 while decreasing ax1, performing exchanges
+.l:
+    blteu ax1, ax0, .r
+
+    xchg b[ax0], b[ax1]
+
+    inc ax0, 1
+    dec ax1, 1
+    jmp .l
+
+.r:
+    ret
+
diff --git a/ka/crt/str/strchr.k b/ka/crt/str/strchr.k
deleted file mode 100644
index e3d3967..0000000
--- a/ka/crt/str/strchr.k
+++ /dev/null
@@ -1,27 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-;
-; char *strchrnul(const char *str, int ch)
-;
-strchrnul:
-    mov rcx, STRLEN_MAX
-    scasb.rep.nz ax0, ax1
-
-    mov rax, ax0
-    ret
-
-;
-; char *strchr(const char *str, int ch)
-;
-strchr:
-    mov rcx, STRLEN_MAX
-    scasb.rep.nz ax0, ax1
-
-    bnz b[ax0], .r
-    mov rax, zero
-    ret
-
-.r:
-    mov rax, ax0
-    ret
diff --git a/ka/crt/str/strcmp.k b/ka/crt/str/strcmp.k
deleted file mode 100644
index 57f87a4..0000000
--- a/ka/crt/str/strcmp.k
+++ /dev/null
@@ -1,51 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-;
-; int strcmp(const char *str1, const char *str2)
-;
-; Returns:
-;    0 if the contents of both strings are equal
-;   >0 if the first character that does not match has a greater value in str1 than in str2
-;   <0 if the first character that does not match has a lower value in str1 than in str2
-;
-strcmp:
-    mov rsi, zero
-.l:
-    movzx rax, b[ax0+rsi]
-    movzx rdx, b[ax1+rsi]
-
-    bne rax, rdx, .r
-
-    ; both zero?
-    add rcx, rax, rdx
-    jrcxz .r
-
-    inc rsi, 1
-    jmp .l
-
-.r:
-    dec rax, rdx
-    ret
-
-;
-; int strncmp(const char *str1, const char *str2, int maxn)
-;
-strncmp:
-    mov rcx, ax2
-    jrcxz .r
-
-.l:
-    movzx rax, b[ax0]
-    movzx rdx, b[ax1]
-
-    bne rax, rdx, .r
-
-    inc ax0, 1
-    inc ax1, 1
-    loop .l
-
-.r:
-    dec rax, rdx
-    ret
-
diff --git a/ka/crt/str/strcpy.k b/ka/crt/str/strcpy.k
deleted file mode 100644
index 10e395c..0000000
--- a/ka/crt/str/strcpy.k
+++ /dev/null
@@ -1,63 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-;
-; void strcpy(char *, const char *)
-;
-strcpy:
-.l:
-    mov rcx, b[ax1]
-    mov b[ax0], rcx
-
-    jrcxz .r
-
-    inc ax0, 1
-    inc ax1, 1
-
-    jmp .l
-
-.r:
-    ret
-
-;
-; void strncpy(char *, const char *, int)
-;
-strncpy:
-    mov rcx, ax2
-    jrcxz .r
-
-.l:
-    mov b[ax0], b[ax1]
-
-    inc ax0, 1
-    inc ax1, 1
-
-    loop .l
-
-.r:
-    ret
-
-;
-; void strnzcpy(char *, const char *, int)
-;
-strnzcpy:
-    mov rcx, ax2
-    jrcxz .r
-
-.l:
-    mov rax, b[ax1]
-    mov b[ax0], rax
-
-    jraxz .r
-
-    inc ax0, 1
-    inc ax1, 1
-
-    loop .l
-
-.z:
-    mov b[ax0], zero
-
-.r:
-    ret
-
diff --git a/ka/crt/str/string.k b/ka/crt/str/string.k
deleted file mode 100644
index ee9d229..0000000
--- a/ka/crt/str/string.k
+++ /dev/null
@@ -1,9 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-include "crt/str/strlen.k"
-include "crt/str/strrev.k"
-include "crt/str/strcpy.k"
-include "crt/str/strcmp.k"
-include "crt/str/strchr.k"
-
diff --git a/ka/crt/str/strlen.k b/ka/crt/str/strlen.k
deleted file mode 100644
index 355a4b4..0000000
--- a/ka/crt/str/strlen.k
+++ /dev/null
@@ -1,24 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-;
-; int strnlen(char *, int)
-;
-strnlen:
-    mov rcx, ax1
-    scasb.rep.nz ax0, zero
-
-    sub rax, ax1, rcx
-    ret
-
-;
-; int strlen(char *)
-;
-strlen:
-    mov rcx, STRLEN_MAX
-    mov rdx, rcx
-    scasb.rep.nz ax0, zero
-
-    sub rax, rdx, rcx
-    ret
-
diff --git a/ka/crt/str/strrev.k b/ka/crt/str/strrev.k
deleted file mode 100644
index cbc97f1..0000000
--- a/ka/crt/str/strrev.k
+++ /dev/null
@@ -1,72 +0,0 @@
-; The OS/K Team licenses this file to you under the MIT license.
-; See the LICENSE file in the project root for more information.
-
-;
-; void strrev(char *buf, const char *str)
-;
-; buf and src must NOT overlap
-;
-strrev:
-    bzr b[ax1], .z
-
-    ; save str's location
-    mov rsi, ax1
-
-    ; go to str's end, just before
-    ; the null terminator
-    mov rcx, STRLEN_MAX
-    scasb.rep.nz ax1, zero
-    dec ax1, 1
-
-.l:
-    ; copy, going backward though str
-    ; and forward through buf
-    mov b[ax0], b[ax1]
-
-    beq ax1, rsi, .r
-
-    inc ax0, 1
-    dec ax1, 1
-    jmp .l
-
-.r:
-    mov b[ax0+1], zero
-    ret
-
-.z:
-    mov b[ax0], zero
-    ret
-
-;
-; void strrev2(char *str)
-;
-; Inverses str
-;
-strrev2:
-    bzr b[ax0], .r
-
-    mov ax1, ax0
-
-    ; go to str's end, just before
-    ; the null terminator
-    mov rcx, STRLEN_MAX
-    scasb.rep.nz ax1, zero
-    dec ax1, 1
-
-    ; increase ax0 while decreasing ax1, performing exchanges
-.l:
-    blteu ax1, ax0, .r
-
-    xchg b[ax0], b[ax1]
-
-    inc ax0, 1
-    dec ax1, 1
-    jmp .l
-
-.r:
-    ret
-
-
-
-
-
diff --git a/ka/crt/lib/time.k b/ka/crt/time.k
similarity index 78%
rename from ka/crt/lib/time.k
rename to ka/crt/time.k
index da6d0e2..bfc006b 100644
--- a/ka/crt/lib/time.k
+++ b/ka/crt/time.k
@@ -45,32 +45,33 @@ DaysInYear:
 ; TIME *GetTimeUTC(void)
 ;
 GetTimeUTC:
-    ytime ax0, ax1, ax2
-    mov rdx, .buf
+    ytime
+
+    mov rdi, .buf
 
     ; seconds
-    rem rcx, ax0, 60
-    mov b[rdx], rcx
+    rem rsi, rax, 60
+    mov b[rdi], rsi
 
     ; minutes
-    div rcx, ax0, 60
-    rem rcx, 60
-    mov b[rdx+1], rcx
+    div rsi, rax, 60
+    rem rsi, 60
+    mov b[rdi+1], rsi
 
     ; hours
-    div rcx, ax0, 3600
-    rem rcx, 24
-    mov b[rdx+2], rcx
+    div rsi, rax, 3600
+    rem rsi, 24
+    mov b[rdi+2], rsi
 
     ; month days
-    div rcx, ax0, 3600*24
-    mov b[rdx+3], rcx
+    div rsi, rax, 3600*24
+    mov b[rdi+3], rsi
 
     ; month
-    mov b[rdx+4], ax1
+    mov b[rdi+4], rbx
 
     ; years
-    mov w[rdx+6], ax2
+    mov w[rdi+6], rcx
 
     ;
     ; ydays (TODO)
diff --git a/ka/doskrnl.k b/ka/doskrnl.k
index 8a3b711..a20e61a 100644
--- a/ka/doskrnl.k
+++ b/ka/doskrnl.k
@@ -26,7 +26,7 @@ start:
     mov rsp, DOSKRNL_STACK
     mov rbp, zero
 
-    ; dump
+    ;dump
 
     call main
 
diff --git a/ka/mkstats.py b/ka/mkstats.py
index 45f79af..520b19b 100755
--- a/ka/mkstats.py
+++ b/ka/mkstats.py
@@ -15,15 +15,13 @@ def mkstat(fp):
         if len(tok) == 0:
             continue
 
-        i = tok[0].split('.')[0]
-
-        if len(i) == 0 or i in ';#@/':
+        if len(tok[0]) == 0 or tok[0] in ';#@/':
             continue
 
-        if i in instrs:
-            instrs[i] += 1
+        if tok[0] in instrs:
+            instrs[tok[0]] += 1
         else:
-            instrs[i] = 1
+            instrs[tok[0]] = 1
 
 for root, _, files in os.walk('.'):
     for f in files:
diff --git a/ka/sys/dumprf.k b/ka/sys/dumprf.k
index 9c9c120..57040c7 100644
--- a/ka/sys/dumprf.k
+++ b/ka/sys/dumprf.k
@@ -9,18 +9,12 @@ dumprf:
     mov r12, ax0
     mov r13, rsp
 
-    call RFS.LoadReg, r12, $cr2
-    push rax
-
     call RFS.LoadReg, r12, $cr1
     push rax
 
     call RFS.LoadReg, r12, $cr0
     push rax
 
-    call RFS.LoadReg, r12, $rfx
-    push rax
-
     call RFS.LoadReg, r12, $rip
     push rax
 
@@ -33,7 +27,7 @@ dumprf:
     call RFS.LoadReg, r12, $trp
     push rax
 
-    push 0 # fixme
+    push zero # fixme
 
     call RFS.LoadReg, r12, $rbp
     push rax
@@ -120,7 +114,7 @@ dumprf:
     leave
     ret
 
-.dmp1 = "Environ #1:\nfrm=0d%d rip=0x%x rfx=0x%x\ncr0=0x%x cr1=0x%x cr2=0x%x\n\n"
+.dmp1 = "Environ #1:\nfrm=0d%d rip=0x%x\ncr0=0x%x cr1=0x%x\n\n"
 .dmp2 = "Environ #2:\nrsp=0x%x rbp=0x%x ind=0d%d\ngrp=0x%x trp=0x%x srp=0x%x\n\n"
 .dmp3 = "Argument:\nax0=0x%x ax1=0x%x ax2=0x%x\nax3=0x%x ax4=0x%x ax5=0x%x\n\n"
 .dmp4 = "Volatile:\nrax=0x%x rbx=0x%x rcx=0x%x\nrdx=0x%x rsi=0x%x rdi=0x%x\n\n"
diff --git a/ka/sys/intr/common.k b/ka/sys/intr/common.k
index 8a62597..8c6d147 100644
--- a/ka/sys/intr/common.k
+++ b/ka/sys/intr/common.k
@@ -11,7 +11,7 @@ ScreenOfDeath:
 
     push ax1
     call printf, .scr1
-    pop zero
+    pop
 
     bnz r14, .not_con
     push .scr2_con
diff --git a/ka/sys/intr/excepts.k b/ka/sys/intr/excepts.k
index 6ca83c5..444a84d 100644
--- a/ka/sys/intr/excepts.k
+++ b/ka/sys/intr/excepts.k
@@ -18,7 +18,7 @@ DefaultExceptionHandler:
 
 .err_ukn = "Unknown exception number\0\0\0\0\0\0\0"
 .err_udf = "Undefined behaviour exception\0\0"
-.err_ill = "Ill-formed exception exception\0"
+.err_ill = "Illformed instruction exception"
 .err_acc = "Invalid memory access exception"
 .err_sys = "Supervisor-only exception used\0"
 .err_dbf = "Double fault exception~~~~~~~~\0"
diff --git a/ka/sys/intr/trap0.k b/ka/sys/intr/trap0.k
index a03ff79..dfee844 100644
--- a/ka/sys/intr/trap0.k
+++ b/ka/sys/intr/trap0.k
@@ -2,14 +2,14 @@
 ; See the LICENSE file in the project root for more information.
 
 TrapHandlers.prolog:
-    mov rbp, zero
+    nul rbp
 
-    ; rax = caller's cr2
-    call RFS.LoadReg, r14, $cr2
+    ; rax = caller's cr1
+    call RFS.LoadReg, r14, $cr1
 
     ; we don't preserve the r12 we got
     mov r12, rax
-    mov rdx, zero
+    nul rdx
 
     jmp rcx
 
@@ -105,12 +105,8 @@ DefaultTrapHandler:
     mov ax2, rcx
     call RFS.StoreReg, zero, $cr1
 
-    ; Data offset
-    mov ax2, rcx
-    call RFS.StoreReg, zero, $cr2
-
     ; Return frame
-    mov r14, zero
+    nul r14
 
     jmp .fini
 
diff --git a/ka/usr/cmd/dir.k b/ka/usr/cmd/dir.k
index affb0ef..d40787a 100644
--- a/ka/usr/cmd/dir.k
+++ b/ka/usr/cmd/dir.k
@@ -10,9 +10,9 @@ builtins.dir:
     push r12, r13
     push r14, r15
 
-    mov r12, zero       # no. of files found
-    mov r13, zero       # no. of directories found
-    mov r14, zero       # total amount of bytes found
+    nul r12     # no. of files found
+    nul r13     # no. of directories found
+    nul r14     # total amount of bytes found
 
     call print, .dirmsg
 
@@ -46,7 +46,7 @@ builtins.dir:
     mov rcx, FNAME_MAX
     mov rsi, .buf
     mov rdi, rsi
-    scasb.rep.nz rsi, '.'
+    scasb rsi, '.'
 
     ; print file name
     sub ax1, rsi, rdi
diff --git a/ka/usr/cmd/main.k b/ka/usr/cmd/main.k
index e670ab5..4c5fb87 100644
--- a/ka/usr/cmd/main.k
+++ b/ka/usr/cmd/main.k
@@ -21,14 +21,16 @@ main:
 .print_prompt:
     call print, prompt
 
-    ; empty argbuf
+    ; empty stuff
     call memzero, argbuf, argbuf.size
-    call nprint, argbuf, argbuf.size
+    call memzero, argv0, argbuf.size
+    nul q[argv1pos]
+
+    # call nprint, argv0, argbuf.size
 
     ; iterator through argbuf
-    mov rcx, zero
+    nul rcx
 
-    mov q[argv1pos], zero
 
 .input_loop:
     pause
@@ -51,7 +53,7 @@ main:
     ; yes, delete it
     dec rcx, 1
     add rdx, rcx, argbuf
-    mov b[rdx], zero
+    nul b[rdx]
 
     ; update screen
     bzr b[stdin_echoing], .input_loop
@@ -86,7 +88,7 @@ main:
     ; find first whitespace or null-terminator
     mov rcx, argbuf.size
     mov rdx, argbuf
-    scasb.rep.nz rdx, ' '
+    scasb rdx, ' '
 
     ; argv1 exists? if so, save its position
     mov rsi, rdx
@@ -108,9 +110,6 @@ main:
     ; fallthrough
 
 .do_extract:
-    ; empty argv0
-    call memzero, argv0, argbuf.size
-
     ; how much do we copy?
     sub rcx, rdx, argbuf
     jrcxz .detect_builtin
diff --git a/vm/dv/cpudev.c b/vm/dv/cpudev.c
index 67eb1e3..2c2887d 100644
--- a/vm/dv/cpudev.c
+++ b/vm/dv/cpudev.c
@@ -250,6 +250,8 @@ long cpudev_idtdone(dev_t *dev)
     if (idt_handling[R(AX0)] == 0)
         _except(E_UDF, "cpudev: idtdone, not handling E/I #%u", R(AX0));
 
+    //trace("IDT.DONE %lu\n", R(AX0));
+
     idt_handling[R(AX0)]--;
 
     return 0;
diff --git a/vm/in/ALU b/vm/in/ALU
index 5a5f83a..57b819d 100644
--- a/vm/in/ALU
+++ b/vm/in/ALU
@@ -5,113 +5,83 @@
 # Logical instructions                                                      #
 #---------------------------------------------------------------------------#
 
-#
-# Bitwise OR operation
-#
-#       $dest = $src1 OR $src2
-#
+# Bitwise NOT
+not 1
+
+# Bitwise OR
 or 2
 or 3
 
-#
-# Bitwise AND operation
-#
-#       $dest = $src1 AND $src2
-#
+# Bitwise AND
 and 2
 and 3
 
-#
-# Bitwise XOR operation
-# 
-#       $dest = $src1 XOR $src2
-#
+# Bitwise XOR
 xor 2
 xor 3
 
-#
-# Logical left/right shift (SHL/SHR)
-#
-#       $dest = $src1 << $src2      (SHL)
-#       $dest = $src1 >> $src2      (SHR)
-#
+# Logical left/right shift
 shl 2
 shl 3
 shr 2
 shr 3
 
-#
-# Arithmetical right shift (SAR)
-#
-#       $dest = $src1 >>> $src2     (SAR)
-#
+# Arithmetical right shift
 sar 2
 sar 3
 
 #---------------------------------------------------------------------------#
 # Arithmetic instructions                                                   #
 #---------------------------------------------------------------------------#
-#
-# Arithmetical ADD operation
-#
-#       $dest1 = $src1 + $src2
-#
+
+# Negation
+neg 1
+
+# Negation but traps on $src == -2^N
+negv 1
+
+# Addition
 add 2
 add 3
 
-#
-# Arithmetical SUB operation
-#
-#       $dest = $src1 - $src2
-#
+# Addition but traps on overflow
+addv 2
+addv 3
+
+# Substraction
 sub 2
 sub 3
 
-#
-# Arithmetical MUL operation
-#
-#       $dest = LO($src1 * $src2)
-#
+# Substraction but traps on underflow
+subv 2
+subv 3
+
+# Multiplication
+# $dest = LO($src1 * $src2)
 mul 2
 mul 3
 
-# Arithmetical unsigned MUL operation
-#
-#       $dest1 = HI($dest2 * $src)
-#       $dest2 = LO($dest2 * $src)
+# Multiplication (unsigned)
+# $dest1 = HI($dest2 * $src)
+# $dest2 = LO($dest2 * $src)
 #
 mulhi 3
 
-# Arithmetical signed MUL operation
-#
-#       $dest1 = HI($dest2 ** $src)
-#       $dest2 = LO($dest2 ** $src)
+# Multiplication (signed)
+# $dest1 = HI($dest2 * $src)
+# $dest2 = LO($dest2 * $src)
 #
 imulhi 3
 
-#
-# Arithmetical unsigned DIV operation
-#
-#       $dest = $src1 DIV $src2
-#
-# Preserves all flags
-#
+# Division (unsigned)
 div 2
 div 3
 
-#
-# Arithmetical signed DIV operation
-#
-#       $dest = $src1 IDIV $src2
-#
+# Division (signed)
 idiv 2
 idiv 3
 
-#
-# Arithmetical modulo operation (REM)
-#
-#       $dest = $src1 MOD $src2
-#
+# Modulo/remainder
 rem 2
 rem 3
 
diff --git a/vm/in/MEM b/vm/in/MEM
index 0569436..5e36dea 100644
--- a/vm/in/MEM
+++ b/vm/in/MEM
@@ -57,14 +57,17 @@ push 3
 #       $1 = *RSP
 #       RSP = RSP + 8
 #
+pop 0
 pop 1
 pop 2
-pop 3
 
 #---------------------------------------------------------------------------#
 # Movement instructions                                                     #
 #---------------------------------------------------------------------------#
 
+nul 1
+nul 2
+
 #
 # Load Effective Address (LEA) instruction
 #
@@ -78,27 +81,22 @@ pop 3
 lea 2
 
 #
-# Move data (MOV) instruction
+# Move data (MOV/MOVU) instructions
 #
-#       $1 = SignExtend($2)
+#       $1 = SignExtend($2)     (MOV)
+#       $1 = ZeroExtend($2)     (MOVU)
 #
 mov 2
-
-#
-# Load from memory with zero-extension (MOVSX/MOVZX) instruction
-#
-#       $1 = ZeroExtend($2)
-#
 movzx 2
 
 #
-# Move with sign-extension (MOVSXx) instruction
+# Move with sign-extension (MOVx) instruction
 #
 #       $1 = SignExtend($2 & (2^(8 * sizeof(x)) - 1)
 #
-movsxb 2
-movsxw 2
-movsxd 2
+movb 2
+movw 2
+movd 2
 
 #
 # Exchange (XCHG) instruction
diff --git a/vm/in/MISC b/vm/in/MISC
index 45efa51..c6bd9c9 100644
--- a/vm/in/MISC
+++ b/vm/in/MISC
@@ -45,7 +45,7 @@ utime 1
 # $2 = current month
 # $3 = current year
 #
-ytime 3
+ytime 0
 
 #
 # Clear all GPR registers except RBP/RSP
diff --git a/vm/in/STRING b/vm/in/STRING
index 8ac4f5d..535f35e 100644
--- a/vm/in/STRING
+++ b/vm/in/STRING
@@ -8,24 +8,18 @@
 #
 # Scan string for a particular value (SCASx)
 #
-#       CMP([%1], $2)
+#   WHILE RCX > 0 DO
+#       RCX = RCX - 1
 #
-#       IF ([%1] == 0) THEN
-#           ZF = 1
-#       ELIF (ZF == 0) THEN
-#           IF (DF == 0) THEN
-#               %1 = %1 + sizeof(x)
-#           ELSE
-#               %1 = %1 - sizeof(x)
-#           FI
+#       IF ([%1] == 0) OR ([%1] == $2) THEN
+#           BREAK
+#       ELSE
+#           %1 = %1 + sizeof(x)
 #       FI
+#   DONE
 #
-# Sets CF, OF and SF according to the result of the comparison
-# Sets ZF according to whether [%1] and $2 are equal, OR if [%1] is null
 #
-# Notes:
-# - Does not move past the value when found
-# - 'SCASB.REP.NZ reg ch' is a short 'strchnul()'
+# Note: Does not move past the value when found
 #
 scasb 2
 scasw 2
diff --git a/vm/in/alu.c b/vm/in/alu.c
index 4e7ae99..fb3f037 100644
--- a/vm/in/alu.c
+++ b/vm/in/alu.c
@@ -8,71 +8,103 @@
 
 //----------------------------------------------------------------------------//
 
-IMPL_START(or, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val | p2->val; return 1; }
-IMPL_START(and, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val & p2->val; return 1; }
-IMPL_START(xor, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val ^ p2->val; return 1; }
+IMPL_START(not, 1) { SRCP(p1); *r1 = ~p1->val; return 1; }
 
+IMPL_START(or, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val | p2->val; return 1; }
 IMPL_START(or, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val | p3->val; return 1; }
+
+IMPL_START(and, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val & p2->val; return 1; }
 IMPL_START(and, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val & p3->val; return 1; }
+
+IMPL_START(xor, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val ^ p2->val; return 1; }
 IMPL_START(xor, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val ^ p3->val; return 1; }
 
 //----------------------------------------------------------------------------//
 
 IMPL_START(shl, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val << p2->val; return 1; }
-IMPL_START(shr, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val >> p2->val; return 1; }
-IMPL_START(sar, 2) { SRCP(p1); SRCP(p2); *r1 = (ulong)((long)p1->val >> (long)p2->val); return 1; }
-
 IMPL_START(shl, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val << p3->val; return 1; }
+
+IMPL_START(shr, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val >> p2->val; return 1; }
 IMPL_START(shr, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val >> p3->val; return 1; }
-IMPL_START(sar, 3) { SRCP(p2); SRCP(p3); *r1 = (ulong)((long)p2->val >> (long)p3->val); return 1; }
+
+IMPL_START(sar, 2) {
+    SRCP(p1); SRCP(p2);
+    *r1 = (ulong)((long)p1->val >> (long)p2->val);
+    return 1;
+}
+IMPL_START(sar, 3) {
+    SRCP(p2); SRCP(p3);
+    *r1 = (ulong)((long)p2->val >> (long)p3->val);
+    return 1;
+}
 
 //----------------------------------------------------------------------------//
 
+IMPL_START(neg, 1) { SRCP(p1); *r1 = ~p1->val + 1; return 1; }
+IMPL_START(negv, 1) {
+    SRCP(p1);
+
+    if (p1->val == (1ul<<63))
+        _except(E_OVF, "Ineffective NEG operation (NEGV)");
+
+    *r1 = ~p1->val + 1;
+
+    return 1;
+}
+
 IMPL_START(add, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val + p2->val; return 1; }
 IMPL_START(add, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val + p3->val; return 1; }
-IMPL_START(addf, 3) { SRCP(p2); SRCP(p3); COMPARE_ADD(p2->val, p3->val); *r1 = p2->val + p3->val; return 1; }
+
+IMPL_START(addv, 2) {
+    SRCP(p1); SRCP(p2);
+
+    ulong rs = p1->val + p2->val;
+
+    if (((p1->val ^ rs) & (p2->val ^ rs)) >> 63)
+        _except(E_OVF, "Signed addition overflow (ADDV#2)"); 
+
+    *r1 = rs;
+    return 1;
+}
+
+IMPL_START(addv, 3) {
+    SRCP(p2); SRCP(p3);
+
+    ulong rs = p2->val + p3->val;
+
+    if (((p2->val ^ rs) & (p3->val ^ rs)) >> 63)
+        _except(E_OVF, "Signed addition overflow (ADDV#3)"); 
+
+    *r1 = rs;
+    return 1;
+}
+
+//----------------------------------------------------------------------------//
 
 IMPL_START(sub, 2) { SRCP(p1); SRCP(p2); *r1 = p1->val - p2->val; return 1; }
 IMPL_START(sub, 3) { SRCP(p2); SRCP(p3); *r1 = p2->val - p3->val; return 1; }
-IMPL_START(subf, 3) { SRCP(p2); SRCP(p3); COMPARE_SUB(p2->val, p3->val); *r1 = p2->val - p3->val; return 1; }
 
-IMPL_START(adcx, 2) {
+IMPL_START(subv, 2) {
     SRCP(p1); SRCP(p2);
 
-    p2->val += !!(R(RFX)&CF);
-    COMPARE_ADD(p1->val, p2->val);
-    *r1 = p1->val + p2->val;
+    ulong rs = p1->val - p2->val;
 
+    if (((p1->val ^ rs) & (p1->val ^ p2->val)) >> 63)
+        _except(E_OVF, "Signed substraction underflow (SUBV#2)");
+
+    *r1 = rs;
     return 1;
 }
 
-IMPL_START(adcx, 3) {
-    SRCP(p2); SRCP(p3);
-
-    p3->val += !!(R(RFX)&CF);
-    COMPARE_ADD(p2->val, p3->val);
-    *r1 = p2->val + p3->val;
-
-    return 1;
-}
-
-IMPL_START(sbbx, 2) {
+IMPL_START(subv, 3) {
     SRCP(p1); SRCP(p2);
 
-    p2->val += !!(R(RFX)&CF); 
-    COMPARE_SUB(p1->val, p2->val);
-    *r1 = p1->val - p2->val;
+    ulong rs = p2->val - p3->val;
 
-    return 1;
-}
-
-IMPL_START(sbbx, 3) {
-    SRCP(p2); SRCP(p3);
-
-    p3->val += !!(R(RFX)&CF); 
-    COMPARE_SUB(p2->val, p3->val);
-    *r1 = p2->val - p3->val;
+    if (((p2->val ^ rs) & (p2->val ^ p3->val)) >> 63)
+        _except(E_OVF, "Signed substraction underflow (SUBV#3)");
 
+    *r1 = rs;
     return 1;
 }
 
diff --git a/vm/in/arch_i.py b/vm/in/arch_i.py
index fa6f668..0c31480 100644
--- a/vm/in/arch_i.py
+++ b/vm/in/arch_i.py
@@ -54,7 +54,7 @@ def parse_2(fp):
                     .format(deprecated, tok[0], n, tok[0], n))
         hd.write("#else\n")
         hd.write("#define I_{}_{} {}\n".format(tok[0].upper(), n, count))
-        hd.write("extern bool i_{}_{}(acc_t *, acc_t *, acc_t *, ulong *, ulong *, ulong *);\n"
+        hd.write("extern bool i_{}_{}(acc_t *, acc_t *, acc_t *, ulong *, ulong *);\n"
                     .format(tok[0], n))
         hd.write("#endif\n\n")
 
diff --git a/vm/in/instrs.h b/vm/in/instrs.h
index c1c925f..13ed995 100644
--- a/vm/in/instrs.h
+++ b/vm/in/instrs.h
@@ -7,7 +7,7 @@
 
 #define IMPL_START(name, n)                                                 \
 uint i_##name##_##n(acc_t *p1, acc_t *p2, acc_t *p3,                        \
-                          ulong *r1, ulong *r2, ulong *r3)                  \
+                          ulong *r1, ulong *r2)                             \
 
 #define XSRCP(v, p, x)                                                      \
     if (ACC_FMT_IS_MEM(p->type))                                            \
@@ -20,52 +20,6 @@ uint i_##name##_##n(acc_t *p1, acc_t *p2, acc_t *p3,                        \
 
 //----------------------------------------------------------------------------//
 
-#define INTO() \
-    if (R(RFX) & OF) _except(E_OVF, "Overflow");
-
-#define PARITY(v) __builtin_parity(v)
-
-#define SET_ZF(v)                                                           \
-    R(RFX) = ((v) == 0 ? (R(RFX)|ZF) : (R(RFX)&~ZF))
-
-#define SET_SF(v)                                                           \
-    R(RFX) = ((long)(v) < 0 ? (R(RFX)|SF) : (R(RFX)&~SF))
-
-#define SET_PF(v)                                                           \
-    R(RFX) = (PARITY(v) == 1 ? (R(RFX)|PF) : (R(RFX)&~PF))
-
-#define SET_ZSF(v)                                                          \
-    SET_ZF(v);                                                              \
-    SET_SF(v)
-
-//----------------------------------------------------------------------------//
-
-#define COMPARE_ADD(v1, v2)                                                 \
-    ulong _u1 = (ulong)v1, _u2 = (ulong)v2, _u3 = (_u1 + _u2);              \
-                                                                            \
-    if (_u1 + _u2 < _u2) R(RFX) |= CF;                                      \
-    else R(RFX) &= ~CF;                                                     \
-                                                                            \
-    if (((_u1 ^ _u3) & (_u2 ^ _u3)) >> 63)                                  \
-        R(RFX) |= OF;                                                       \
-    else R(RFX) &= ~OF;                                                     \
-                                                                            \
-    SET_ZSF(_u3);
-
-#define COMPARE_SUB(v1, v2)                                                 \
-    ulong _u1 = (ulong)v1, _u2 = (ulong)v2, _u3 = (_u1 - _u2);              \
-                                                                            \
-    if (_u1 < _u2) R(RFX) |= CF;                                            \
-    else R(RFX) &= ~CF;                                                     \
-                                                                            \
-    if (((_u1 ^ _u3) & (_u1 ^ _u2)) >> 63)                                  \
-        R(RFX) |= OF;                                                       \
-    else R(RFX) &= ~OF;                                                     \
-                                                                            \
-    SET_ZSF(_u3);
-
-//----------------------------------------------------------------------------//
-
 #define CHK_SUPERV()                                                        \
     do {                                                                    \
         if ((R(CR0) & UF) > 0) {                                            \
diff --git a/vm/in/jmp.c b/vm/in/jmp.c
index 0d1ba15..c14b608 100644
--- a/vm/in/jmp.c
+++ b/vm/in/jmp.c
@@ -13,6 +13,8 @@ IMPL_START(jrcxz, 1) { if (!R(RCX)) R(RIP) = p1->val; return 0; }
 IMPL_START(jraxnz, 1) { if (R(RAX)) R(RIP) = p1->val; return 0; }
 IMPL_START(jrcxnz, 1) { if (R(RCX)) R(RIP) = p1->val; return 0; }
 
+//----------------------------------------------------------------------------//
+
 IMPL_START(loop, 1) {
     if (R(RCX) > 0) {
         R(RCX)--;
@@ -21,6 +23,17 @@ IMPL_START(loop, 1) {
     return 0;
 }
 
+IMPL_START(loop, 2) {
+    SRCP(p1);
+    if (p1->val > 0) {
+        *r1 = p1->val-1;
+        R(RIP) = p2->val;
+    }
+    return 0;
+}
+
+//----------------------------------------------------------------------------//
+
 IMPL_START(bzr, 2) { SRCP(p1); if (p1->val == 0) R(RIP) = p2->val; return 0; }
 IMPL_START(bnz, 2) { SRCP(p1); if (p1->val != 0) R(RIP) = p2->val; return 0; }
 IMPL_START(bltz, 2) { SRCP(p1); if ((long)p1->val < 0) R(RIP) = p2->val; return 0; }
@@ -34,24 +47,5 @@ IMPL_START(bltu, 3) { SRCP(p1); if (p1->val < p2->val) R(RIP) = p3->val; return
 IMPL_START(blte, 3) { SRCP(p1); if ((long)p1->val <= (long)p2->val) R(RIP) = p3->val; return 0; }
 IMPL_START(blteu, 3) { SRCP(p1); if (p1->val <= p2->val) R(RIP) = p3->val; return 0; }
 
-IMPL_START(bch, 3)
-{
-    SRCP(p1);
-    SRCP(p2);
+//----------------------------------------------------------------------------//
 
-    COMPARE_SUB(p1->val, p2->val);
-
-    if (eval_cond(ctx->cond))
-        R(RIP) = p3->val;
-
-    return 0;
-}
-
-IMPL_START(cmp, 2)
-{
-    SRCP(p1);
-
-    COMPARE_SUB(p1->val, p2->val);
-
-    return 0;
-}
diff --git a/vm/in/mem.c b/vm/in/mem.c
index fd96393..9646238 100644
--- a/vm/in/mem.c
+++ b/vm/in/mem.c
@@ -6,12 +6,16 @@
 //----------------------------------------------------------------------------//
 
 IMPL_START(lea, 2) { *r1 = p2->addr; return 1; }
+
 IMPL_START(mov, 2) { XSRCP(*r1, p2, sx); return 1; }
 IMPL_START(movzx, 2) { XSRCP(*r1, p2, zx); return 1; }
 
-IMPL_START(movsxb, 2) { SRCP(p2); *r1 = (ulong)(long)(char)p2->val; return 1; }
-IMPL_START(movsxw, 2) { SRCP(p2); *r1 = (ulong)(long)(short)p2->val; return 1; }
-IMPL_START(movsxd, 2) { SRCP(p2); *r1 = (ulong)(long)(int)p2->val; return 1; }
+IMPL_START(movb, 2) { SRCP(p2); *r1 = (ulong)(long)(char)p2->val; return 1; }
+IMPL_START(movw, 2) { SRCP(p2); *r1 = (ulong)(long)(short)p2->val; return 1; }
+IMPL_START(movd, 2) { SRCP(p2); *r1 = (ulong)(long)(int)p2->val; return 1; }
+
+IMPL_START(nul, 1) { *r1 = 0; return 1; }
+IMPL_START(nul, 2) { *r1 = 0; *r2 = 0; return 2; }
 
 IMPL_START(xchg, 2)
 {
@@ -64,6 +68,12 @@ IMPL_START(push, 3)
 
 //----------------------------------------------------------------------------//
 
+IMPL_START(pop, 0)
+{
+    R(RSP) += 8;
+    return 0;
+}
+
 IMPL_START(pop, 1)
 {
     *r1 = readmemzx(R(RSP), 8);
@@ -81,16 +91,6 @@ IMPL_START(pop, 2)
     return 2;
 }
 
-IMPL_START(pop, 3)
-{
-    *r1 = readmemzx(R(RSP) + 0, 8);
-    *r2 = readmemzx(R(RSP) + 8, 8);
-    *r3 = readmemzx(R(RSP) + 16, 8);
-    R(RSP) += 24;
-    
-    return 3;
-}
-
 //----------------------------------------------------------------------------//
 
 IMPL_START(call, 1)
@@ -144,6 +144,14 @@ IMPL_START(ret, 0)
     return 0;
 }
 
+IMPL_START(ret, 1)
+{
+    R(RIP) = readmemzx(R(RSP), 8);
+    R(RSP) += 8 + (p1->val * 8);
+
+    return 0;
+}
+
 //----------------------------------------------------------------------------//
 
 IMPL_START(enter, 0)
diff --git a/vm/in/misc.c b/vm/in/misc.c
index e28faf8..021361f 100644
--- a/vm/in/misc.c
+++ b/vm/in/misc.c
@@ -9,7 +9,6 @@
 
 //----------------------------------------------------------------------------//
 
-IMPL_START(into, 0) { INTO(); return 0; }
 IMPL_START(pause, 0) { usleep(5000); return 0; }
 IMPL_START(udf, 0) { _except(E_UDF, "UDF instruction"); }
 
@@ -35,7 +34,7 @@ IMPL_START(dump, 0)
         trace("0x%lX:\t...\n", ctx->cur_pc);
 
     else if (!ctx->dumpsw)
-        dump_instr(ctx->cur_in, p1, p2, p3, 0, 0);
+        dump_instr(ctx->cur_in, p1, p2, p3);
 
     ctx->dumpsw = !ctx->dumpsw;
 #endif
@@ -44,19 +43,19 @@ IMPL_START(dump, 0)
 
 //----------------------------------------------------------------------------//
 
-IMPL_START(ytime, 3)
+IMPL_START(ytime, 0)
 {
     time_t t = time(NULL);
     struct tm *tm = localtime(&t);
 
-    *r1 = tm->tm_sec + tm->tm_min * 60
-                    + tm->tm_hour * 60 * 60
-                    + tm->tm_mday * 60 * 60 * 24;
+    R(RAX) = tm->tm_sec + tm->tm_min * 60
+           + tm->tm_hour * 60 * 60
+           + tm->tm_mday * 60 * 60 * 24;
 
-    *r2 = tm->tm_mon;
-    *r3 = tm->tm_year + 1900;
+    R(RBX) = tm->tm_mon;
+    R(RCX) = tm->tm_year + 1900;
 
-    return 3;
+    return 0;
 }
 
 IMPL_START(utime, 1)
@@ -72,7 +71,6 @@ IMPL_START(utime, 1)
 
 IMPL_START(cls, 0)
 {
-    R(RFX) = 0;
     for (int i = RAX; i <= R20; i++) R(i) = 0;
 
     return 0;
@@ -148,6 +146,8 @@ IMPL_START(prn, 1)
             break;
 
         default:
+            trace("PRN bad magic: %lx\n", v);
+            die(1);
             _except(E_ILL, "Bad PRN magic");
         }
     }
@@ -158,28 +158,6 @@ IMPL_START(prn, 1)
     return 0;
 }
 
-IMPL_START(prns, 1)
-{
-    if (p1->type != A_REG)
-        _except(E_ILL, "PRNS given a non-REG operand");
-
-    uchar ch = readmemzx(R(p1->reg), 1);
-
-    COMPARE_SUB(ch, 0);
-
-    if ((R(RFX) & ZF) == 0)
-    {
-        console_putc(ch);
-
-        if (R(RFX) & DF)
-            R(p1->reg)--;
-        else
-            R(p1->reg)++;
-    }
-
-    return 0;
-}
-
 IMPL_START(scan, 1)
 {
     *r1 = console_scankeybuf();
diff --git a/vm/in/string.c b/vm/in/string.c
index 878f19c..6ab7338 100644
--- a/vm/in/string.c
+++ b/vm/in/string.c
@@ -11,36 +11,21 @@
 
 //----------------------------------------------------------------------------//
 
-static void stos_impl(acc_t *p1, acc_t *p2, uint len)
-{
-    if (p1->type != A_REG)
-        _except(E_ILL, "STOSX given a non-REG operand");
-
-    writemem(p2->val, R(p1->reg), len);
-    STR_MOVE(p1->reg, len);
-}
-
-IMPL_START(stosb, 2) { stos_impl(p1, p2, 1); return 0; }
-IMPL_START(stosw, 2) { stos_impl(p1, p2, 2); return 0; }
-IMPL_START(stosd, 2) { stos_impl(p1, p2, 4); return 0; }
-IMPL_START(stosq, 2) { stos_impl(p1, p2, 8); return 0; }
-
-//----------------------------------------------------------------------------//
-
 static void scas_impl(acc_t *p1, acc_t *p2, uint len)
 {
     if (p1->type != A_REG)
         _except(E_ILL, "SCASX given a non-REG operand");
 
-    ulong x = readmemsx(R(p1->reg), len);
-    COMPARE_SUB(x, p2->val);
+    while (R(RCX) > 0)
+    {
+        ulong x = readmemzx(R(p1->reg), len);
 
-    if (x == 0) {
-        R(RFX) |= ZF;
-    }
+        if (x == 0 || x == p2->val)
+            break;
 
-    else if (!(R(RFX)&ZF)) {
-        STR_MOVE(p1->reg, len);
+        R(p1->reg) += len;
+
+        R(RCX)--;
     }
 }
 
diff --git a/vm/pc/DECD b/vm/pc/DECD
index a2d0979..6d684fd 100644
--- a/vm/pc/DECD
+++ b/vm/pc/DECD
@@ -3,11 +3,7 @@
 
 Instruction encoding:
 
-Byte 1: Instruction number
-Byte 2:
-xx0xxxxx
-|| └───┘
-RL  CND
+Byte: Instruction number
 
 Values for ModRMs:
 000xxxxx    xxxxx = reg
@@ -24,19 +20,3 @@ Values for ModRMs:
 11100100    imm32       (zero extended)
 11101000    imm64       (zero extended)
 
-Values for COND:
-00000       (none)
-00001       .C .B
-00010       .O
-00011       .Z .E
-00100       .S
-00101       .P
-00110       .BE
-00111       .L
-01000       .LE
-01001       .AXZ
-01010       .BXZ
-01011       .CXZ
-01100       .DXZ
-Highest (6th) bit of COND indicates negation
-
diff --git a/vm/pc/arch.h b/vm/pc/arch.h
index 79cd465..7fc294a 100644
--- a/vm/pc/arch.h
+++ b/vm/pc/arch.h
@@ -72,9 +72,6 @@ struct ctx_t
     ulong ninstrs;      // totally
     ulong ni_thisfr;    // this frame
 
-    // Last COND field
-    uint cond;
-
     // Dumpinstr switch
     bool dumpsw;
 };
diff --git a/vm/pc/decode.c b/vm/pc/decode.c
index 0a3272f..bdca68f 100644
--- a/vm/pc/decode.c
+++ b/vm/pc/decode.c
@@ -195,8 +195,8 @@ static void extract_param(instr_t *in, acc_t *p)
 //
 void decode(void)
 {
+    ushort b;
     instr_t *in;
-    ushort b1, b2, rep = 0, lock;
     acc_t p1 = { 0 }, p2 = { 0 }, p3 = { 0 };
 
     //logerr("decodin'\n");
@@ -209,35 +209,20 @@ void decode(void)
         _except(E_ACC, "Executing out of memory");
 
     // Instruction bytes
-    b1 = fetchb();
-
-    // Suffixes?
-    if (b1 & (1 << 7))
-    {
-        b1 &= ~(1 << 7);
-        b2 = fetchb();
-    }
-
-    else
-        b2 = 0;
+    b = fetchb();
 
     // Renge check
-    if (b1 >= NINSTRS)
-        _except(E_ILL, "No such INSTR: 0x%hhX", b1);
+    if (b >= NINSTRS)
+        _except(E_ILL, "No such INSTR: 0x%hhX", b);
 
     // Find instruction
-    in = &ctx->i[b1];
+    in = &ctx->i[b];
     ctx->cur_in = in;
 
-    // Get flags/etc
-    rep = !!(b2 & SUFF_REP);
-    lock = !!(b2 & SUFF_LOCK);
-    ctx->cond = b2 & SUFF_COND;
-
     // Operand 1?
     if (in->nprms == 0)
     {
-        exec_instr(in, NULL, NULL, NULL, lock, rep);
+        exec_instr(in, NULL, NULL, NULL);
         return;
     }
 
@@ -246,7 +231,7 @@ void decode(void)
     // Operand 2?
     if (in->nprms == 1)
     {
-        exec_instr(in, &p1, NULL, NULL, lock, rep);
+        exec_instr(in, &p1, NULL, NULL);
         return;
     }
 
@@ -255,12 +240,12 @@ void decode(void)
     // Operand 1?
     if (in->nprms == 2)
     {
-        exec_instr(in, &p1, &p2, NULL, lock, rep);
+        exec_instr(in, &p1, &p2, NULL);
         return;
     }
 
     extract_param(in, &p3);
 
-    exec_instr(in, &p1, &p2, &p3, lock, rep);
+    exec_instr(in, &p1, &p2, &p3);
 }
 
diff --git a/vm/pc/decode.h b/vm/pc/decode.h
index 517a323..b84ea33 100644
--- a/vm/pc/decode.h
+++ b/vm/pc/decode.h
@@ -1,30 +1,6 @@
 // The OS/K Team licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-enum
-{
-    CD_NONE,
-    CD_C,
-    CD_O,
-    CD_Z,
-    CD_S,
-    CD_P,
-    CD_BE,
-    CD_L,
-    CD_LE,
-    CD_AXZ,
-    CD_BXZ,
-    CD_CXZ,
-    CD_DXZ,
-};
-
-enum
-{
-    SUFF_REP = (1 << 7),
-    SUFF_LOCK = (1 << 6),
-    SUFF_COND = 0b00011111,
-};
-
 enum
 {
     A_NONE      = 0,
@@ -68,22 +44,16 @@ struct instr_t
     char   *name;
     uint    nprms;
     uint  (*func)(acc_t *, acc_t *, acc_t *,
-                  ulong *, ulong *, ulong *);
+                  ulong *, ulong *);
 };
 
-bool eval_cond(uint cond);
-
 void exec_instr(instr_t *in,
                 acc_t *p1,
                 acc_t *p2,
-                acc_t *p3,
-                bool lock,
-                bool rep);
+                acc_t *p3);
 
 void dump_instr(instr_t *in,
                 acc_t *p1,
                 acc_t *p2,
-                acc_t *p3,
-                bool lock,
-                bool rep);
+                acc_t *p3);
 
diff --git a/vm/pc/dump.c b/vm/pc/dump.c
index 6f94e28..00f538f 100644
--- a/vm/pc/dump.c
+++ b/vm/pc/dump.c
@@ -5,53 +5,15 @@
 
 #define ABS(x) ((short)(x) < 0 ? -x : x)
 
-static const char *cond_suffixes[] =
-{
-    "-",
-    "c", "o", "z", "s", "p",
-    "be", "l", "le", "axz",
-    "bxz", "cxz",
-    "?"
-};
-
 static void dump_acc(acc_t *p);
 
 void dump_instr(instr_t *in,
                 acc_t *p1,
                 acc_t *p2,
-                acc_t *p3,
-                bool lock,
-                bool rep)
+                acc_t *p3)
 {
-    uint cond = ctx->cond;
-
     trace("0x%lX:\t", ctx->cur_pc);
-
-    if (lock)
-        trace("lock");
-
-    trace("%s", in->name);
-
-    if (rep)
-        trace(".rep");
-
-    if (cond)
-    {
-        trace(".");
-
-        if (cond & (1 << 4))
-            trace("n");
-
-        assert((cond & ~(1 << 4)) <= sizeof(cond_suffixes)/sizeof(char *));
-
-        trace("%s", cond_suffixes[cond & ~(1 << 4)]);
-    }
-    
-    if (!rep && cond != ((1 << 4) | CD_CXZ))
-        trace("\t\t");
-
-    else
-        trace("\t");
+    trace("%s\t", in->name);
 
     if (p1)
         dump_acc(p1);
diff --git a/vm/pc/except.c b/vm/pc/except.c
index 5b9aafb..56c600a 100644
--- a/vm/pc/except.c
+++ b/vm/pc/except.c
@@ -75,7 +75,7 @@ void _except(int _code, char *fmt, ...)
     {
         if (ctx->dumpsw)
         {
-            trace("\nException %u - ", code);
+            trace("\n(Caught) Exception %u - ", code);
 
             va_start(ap, fmt);
             vprintf(fmt, ap);
diff --git a/vm/pc/exec.c b/vm/pc/exec.c
index 7ff6237..b968d5d 100644
--- a/vm/pc/exec.c
+++ b/vm/pc/exec.c
@@ -3,41 +3,6 @@
 
 #include <pc/arch.h>
 
-#define rfx R(RFX)
-
-bool eval_cond(uint cond)
-{
-    bool neg = cond & (1 << 4);
-    bool ok;
-    
-    cond &= ~(1 << 4);
-    
-    switch (cond)
-    {
-        case CD_NONE: ok = 1;   break;
-
-        case CD_C: ok = rfx&CF; break;
-        case CD_O: ok = rfx&OF; break;
-        case CD_Z: ok = rfx&ZF; break;
-        case CD_S: ok = rfx&SF; break;
-        case CD_P: ok = rfx&PF; break;
-
-        case CD_BE: ok = rfx&CF || rfx&ZF;                      break;
-        case CD_L:  ok = !(rfx&SF) != !(rfx&OF);                break;
-        case CD_LE: ok = rfx&ZF || (!(rfx&SF) != !(rfx&OF));    break;
-
-        case CD_AXZ: ok = !R(RAX); break;
-        case CD_BXZ: ok = !R(RBX); break;
-        case CD_CXZ: ok = !R(RCX); break;
-        case CD_DXZ: ok = !R(RDX); break;
-
-        default:
-            _except(E_ILL, "Invalid COND value: 0x%x", (neg?cond|(1<<4):cond));
-    }
-    
-    return neg ? !ok : !!ok;
-}
-
 #define OUTPUT(p, r) {                                                      \
     if (p->type == A_REG)                                                   \
         R(p->reg) = r;                                                      \
@@ -52,54 +17,26 @@ bool eval_cond(uint cond)
 void exec_instr(instr_t *in,
                 acc_t *p1,
                 acc_t *p2, 
-                acc_t *p3, 
-                bool lock,
-                bool rep)
+                acc_t *p3)
 {
     uint out;
-    ulong r1 = 0, r2 = 0, r3 = 0;
+    ulong r1 = 0, r2 = 0;
 
     // Global instruction counter
     ctx->ninstrs++;
 
-    //
-    // For REPs we evaluate the condition AFTER running the instruction,
-    // in a do ... while(cond) fashion
-    //
-    if (ctx->cond)
-        if (!rep && !eval_cond(ctx->cond))
-            return;
-
     if (ctx->dumpsw)
-        dump_instr(in, p1, p2, p3, lock, rep);
+        dump_instr(in, p1, p2, p3);
 
-do_rep:
-    out = in->func(p1, p2, p3, &r1, &r2, &r3);
+    out = in->func(p1, p2, p3, &r1, &r2);
 
     if (out)
     {
         OUTPUT(p1, r1);
-        if (out >= 2) OUTPUT(p2, r2);
-        if (out >= 3) OUTPUT(p3, r3);
+        if (__builtin_expect(out == 2, 0))
+            OUTPUT(p2, r2);
+
         R(RZX) = 0;
     }
-
-    if (rep)
-    {
-        // RCX remains untouched when condition fails
-        if (!eval_cond(ctx->cond))
-            return;
-
-        if (R(RCX) > 0)
-            R(RCX)--;
-
-        if (R(RCX) == 0)
-            return;
-
-        // Should we really count REP's in instruction count?
-        ctx->ninstrs++;
-
-        goto do_rep;
-    }
 }
 
diff --git a/vm/pc/mem.c b/vm/pc/mem.c
index 2df44d3..b7779f0 100644
--- a/vm/pc/mem.c
+++ b/vm/pc/mem.c
@@ -106,7 +106,7 @@ static void writemem64(ulong val, ulong real, ulong addr)
     }
 
 #define GETREAL()                                                           \
-    ulong real = addr2real(addr + R(CR2))
+    ulong real = addr2real(addr + R(CR1))
 
 //----------------------------------------------------------------------------//
 
diff --git a/vm/pc/regs.c b/vm/pc/regs.c
index 85181fc..0b8cc65 100644
--- a/vm/pc/regs.c
+++ b/vm/pc/regs.c
@@ -5,9 +5,6 @@
 
 reg_t arch_r[] =
 {
-    { "zero", GPR },  { "cr0", SYS }, { "cr1", SYS }, { "cr2", SYS },
-    { "rfx", GPR }, { "rip", GPR }, { "rbp", GPR }, { "rsp", GPR },
-
     { "rax", GPR }, { "rbx", GPR }, { "rcx", GPR }, { "rdx", GPR },
     { "rsi", GPR }, { "rdi", GPR }, { "ax0", GPR }, { "ax1", GPR },
     { "ax2", GPR }, { "ax3", GPR }, { "ax4", GPR }, { "ax5", GPR },
@@ -15,6 +12,9 @@ reg_t arch_r[] =
     { "r12", GPR }, { "r13", GPR }, { "r14", GPR }, { "r15", GPR },
     { "r16", GPR }, { "r17", GPR }, { "r18", GPR }, { "r19", GPR },
     { "r20", GPR }, { "grp", GPR }, { "trp", GPR }, { "srp", SYS },
+
+    { "tmp", GPR }, { "rad", GPR }, { "cr0", SYS }, { "cr1", SYS },
+    { "rip", GPR }, { "rbp", GPR }, { "rsp", GPR }, { "zero", GPR },
 };
 
 static_assert(sizeof(arch_r)/sizeof(reg_t) == NREGS, "");
@@ -26,8 +26,8 @@ void dumpregs()
     TRACE("Current RFRAME index: #%lu", rfs_current_idx);
 
     TRACE("\n\nEnviron #1:");
-    TRACE("\nrpc=0x%-16lX rip=0x%-16lX rfx=0x%-16lX", ctx->cur_pc, R(RIP), R(RFX));
-    TRACE("\ncr0=0x%-16lX cr1=0x%-16lX cr2=0x%-16lX", R(CR0), R(CR1), R(CR2));
+    TRACE("\nrpc=0x%-16lX rip=0x%-16lX", ctx->cur_pc, R(RIP));
+    TRACE("\ncr0=0x%-16lX cr1=0x%-16lX", R(CR0), R(CR1));
 
     TRACE("\n\nEnviron #2:");
     TRACE("\nrsp=0x%-16lX rbp=0x%-16lX ins=0d%-16lu", R(RSP), R(RBP), ctx->ninstrs);
diff --git a/vm/pc/regs.h b/vm/pc/regs.h
index a7de68f..ea73bed 100644
--- a/vm/pc/regs.h
+++ b/vm/pc/regs.h
@@ -37,10 +37,10 @@ struct reg_t
 
 enum
 {
-    RZX, CR0, CR1, CR2, RFX, RIP, RBP, RSP,
     RAX, RBX, RCX, RDX, RSI, RDI, AX0, AX1,
     AX2, AX3, AX4, AX5, R12, R13, R14, R15,
     R16, R17, R18, R19, R20, GRP, TRP, SRP,
+    TMP, RAD, CR0, CR1, RIP, RBP, RSP, RZX,
 
     NREGS
 };
diff --git a/vm/pc/sym.c b/vm/pc/sym.c
index 68babd2..e5f0987 100644
--- a/vm/pc/sym.c
+++ b/vm/pc/sym.c
@@ -18,9 +18,9 @@ int create_symtab(const char *name)
         return -1;
     }
 
-    while (fscanf(tab, "%s %lu\n", buf, &addr) > 0 && it < SYMTAB_LEN)
+    while (fscanf(tab, "%45s%*s %lu\n", buf, &addr) > 0 && it < SYMTAB_LEN)
     {
-        // log("SYM: '%.*s' '%lu'\n", SYMLEN_MAX, buf, addr);
+        //trace("SYM: '%.*s' '%lu'\n", SYMLEN_MAX, buf, addr);
 
         if (prev_addr > addr)
         {
@@ -38,7 +38,6 @@ int create_symtab(const char *name)
     }
 
     fclose(tab);
-	
     return 0;
 }
 
diff --git a/vm/pc/sym.h b/vm/pc/sym.h
index 014a157..959bdf8 100644
--- a/vm/pc/sym.h
+++ b/vm/pc/sym.h
@@ -1,7 +1,7 @@
 // The OS/K Team licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-#define SYMLEN_MAX 32
+#define SYMLEN_MAX 46
 #define SYMTAB_LEN 4096
 
 typedef struct sym_t        sym_t;
@@ -9,7 +9,7 @@ typedef struct sym_t        sym_t;
 struct sym_t
 {
     ulong addr;
-    char name[SYMLEN_MAX];
+    char name[SYMLEN_MAX+1];
 };
 
 extern sym_t symtab[SYMTAB_LEN];