diff --git a/scu-dsp/parse10.asm b/scu-dsp/parse10.asm
index cf1e356..afbbcb8 100644
--- a/scu-dsp/parse10.asm
+++ b/scu-dsp/parse10.asm
@@ -4,36 +4,55 @@
         ;;                             mov mc0,ra0
 
         ;; variables:
-        ;; m0[0] dma read start address (global)
+        ;; m0[0]
         ;; m0[1] dma read value (local); post-shift 4-byte remainder (global)
         ;; m0[2] saved accumulator (global)
 
-caller_setup:
-        mov 0,ct0
-        ;; start address
-        mov mc0,ra0
-        mov 2,ct0
-        ;; mov 0,mc0
+setup:
+        ;;   [X       ]   [Y       ]   [D1       ]
+                                       mov 1,ct0
+                                       mov 0,ct3
+                                       mov 0,mc0
+                                       mov 0,mc0
+        mvi parse_base10,pc
+                                       mov 1,lop
+        ;; parse_base10 return
+                                       mov all,mc3
+
+        mvi parse_base10,pc
+                                       mov 1,lop
+        ;; parse_base10 return
+                                       mov all,mc3
+
+        nop
+        nop
+        nop
 
 parse_base10:
-next_chunk:
-                          clr a        mov 1,ct0
+        ;;   [X       ]   [Y       ]   [D1       ]
+                                       mov 1,ct0
+             mov m0,p     mov m0,a
+        add
+        jmp nz,parse_loop
+                          clr a        ; delay slot
+dma_next_chunk:
         ;; dma d0,mc0,1
         ;; begin fake number 0x39322033 "92 3"
         mvi 0x393220,pl
         add               mov alu,a    mov 0x33,pl
-        rl8               mov alu,a
+        rl8               mov alu,a    mov 1,ct0
         add                            mov all,mc0
         ;; end fake number
-post_dma_load:
+end_dma_next_chunk:
+parse_loop:
         ;; extract first (leftmost) digit
                                        mov 1,ct0
                           mov mc0,a    mov 0x7f,pl
-        rl8               mov alu,a    ;;mov all,mc0 ; m0[1] 0x20323339
-        ;; multiply saved accumulator by 10
-        ;;   [X       ]   [Y       ]   [D1       ]
-                          mov m0,y     mov 10,rx     ; m0[2] 0x00000000
-        and                            mov all,pl
+        or
+        jmp s,end_of_input
+        rl8               mov alu,a    mov 10,rx     ; m0[2] 0x00000000
+        jmp z,dma_next_chunk
+        and               mov m0,y     mov all,pl
 
         ;; MUL: post-multiplication accumulator
         ;; P: post-mask digit
@@ -41,8 +60,6 @@ post_dma_load:
                                        mov 1,ct0
         xor               clr a        mov all,mc0 ; m0[1] 0x20323300
 
-        ;; FIXME: if 0x00 jump to "end of input"?
-
         add               mov alu,a    mov 0x30,pl ; 0x30 ascii '0'
 
         ;; A: post-mask digit
@@ -52,7 +69,7 @@ post_dma_load:
         ;; if ((0x39 - 0x30) < 0) goto non_digit;
         jmp s,non_digit
         ;; possibly set S flag for `jmp ns,non_digit`
-        sub                                        ; sub in delay slot
+        sub                            mov 2,ct0   ; sub in delay slot
         ;; if (((0x39 - 0x30) - 10) >= 0) goto non_digit;
         jmp ns,non_digit
                           mov mul,p    mov 2,ct0   ; mov in delay slot
@@ -60,14 +77,17 @@ post_dma_load:
 digit:
         ;; we have a valid digit; add it to the accumulator; save to m0[2]
         ;;   [X       ]   [Y       ]   [D1       ]
-        jmp post_dma_load
+        jmp parse_loop
         add                            mov all,mc0 ; add in delay slot ; m0[2] 0x00000009
 
 non_digit:
-        ;; this is not a valid digit; return the accumulator
+        ;; this is not a valid digit; return and clear the accumulator as A
         ;;   [X       ]   [Y       ]   [D1       ]
         btm
-                          clr a                    ; clr in delay slot
+                          mov m0,a     mov 0,mc0   ; clr in delay slot ; m0[2]
 
         ;; m0:
         ;; 00000000 32330000 00000009 0000000
+end_of_input:
+        btm
+                          clr a