I finally figured out how the serial connection works so here is a DM15 M1B friendly memory dump for SwissMicros users:
DM15_M1B
04 000000fffff000 00000000000008 0000000000000c 00000000000eae
08 00000000000000 2faf8befbe2280 00000000000000 00000000000000
14 00000000000000 1b2d2d2d2d2d2d 000000000006e7 00000000000000
18 00000000000000 0000000000007f 00000000a00000 00000000000000
e4 00000000000000 00000000000000 00000000000000 00b2ebfcf0f1a3
e8 fdc586ccfbc5b1 fcf0f1a397fdf0 f10eb286971e50 ff3000ff1980df
ec c351fff1b2ec32 a2df75f1fbf720 ff82df75f1fbf6 20ff0931ff42f0
f0 b2ec8697310819 41ff42f0b27086 973107b29649ff c239ffa2973106
f4 b2dc86973105b2 bddff1973104b2 9ddff1973103b2 81dff102b2a1df
f8 f101c2b400b212 ff9596a251ff31 ffec8602ff97f9 f1f0c0f341ff0c
fc 11ff80dff18997 20ff01ff42f041 f9f140fc50fff3 c1f0f12c60ff0b
A: 000000fffff000 B: 000000fffffeae C: 00000000000eae
S: 00000000000000
M: 395033178ff000 N: 00000000000000 G: 04
...and if you want to enter the code by hand here is a debug friendly program listing:
001 LBL B | 42,21,12
002 FIX 0 | 42, 7, 0
003 GSB C | 32 13
004 1 | 1
005 0 | 0
006 ENTER | 36
007 3 | 3
008 F? 0 | 43, 6, 0
009 * | 20
010 STO 0 | 44 0
011 1 | 1
012 9 | 9
013 STO 1 | 44 1
014 0 | 0
015 STO 2 | 44 2
016 LBL .1 | 42,21,.1
017 GSB .0 | 32 .0
018 STO I | 44 25
019 GSB I | 32 25
020 1 | 1
021 STO+0 | 44,40, 0
022 GTO .1 | 22 .1
023 LBL C | 42,21,13
024 CF 1 | 43, 5, 1
025 3 | 3
026 . | 48
027 0 | 0
028 1 | 1
029 9 | 9
030 STO I | 44 25
031 LBL .2 | 42,21,.2
032 RCL (i) | 45 24
033 x=0 | 43 20
034 SF 1 | 43, 4, 1
035 F? 1 | 43, 6, 1
036 CLx | 43 35
037 STO (i) | 44 24
038 ISG I | 42, 6,25
039 GTO .2 | 22 .2
040 RTN | 43 32
041 LBL 0 | 42,21, 0
042 R_up | 43 33
043 R/S | 31
044 LBL 1 | 42,21, 1
045 1 | 1
046 STO-1 | 44,30, 1
047 RTN | 43 32
048 LBL 2 | 42,21, 2
049 1 | 1
050 STO+1 | 44,40, 1
051 RTN | 43 32
052 LBL 3 | 42,21, 3
053 RCL 1 | 45 1
054 STO I | 44 25
055 1 | 1
056 STO+(i) | 44,40,24
057 RTN | 43 32
058 LBL 4 | 42,21, 4
059 RCL 1 | 45 1
060 STO I | 44 25
061 1 | 1
062 STO-(i) | 44,30,24
063 RTN | 43 32
064 LBL 5 | 42,21, 5
065 RCL 1 | 45 1
066 STO I | 44 25
067 RCL (i) | 45 24
068 PSE | 42 31
069 RTN | 43 32
070 LBL 6 | 42,21, 6
071 RCL 1 | 45 1
072 STO I | 44 25
073 CLx | 43 35
074 SF 9 | 43, 4, 9
075 R/S | 31
076 CF 9 | 43, 5, 9
077 STO (i) | 44 24
078 RTN | 43 32
079 LBL 7 | 42,21, 7
080 RCL 1 | 45 1
081 STO I | 44 25
082 RCL (i) | 45 24
083 TEST 0 | 43,30, 0
084 RTN | 43 32
085 0 | 0
086 STO 2 | 44 2
087 CF 1 | 43, 5, 1
088 GTO 9 | 22 9
089 LBL 8 | 42,21, 8
090 RCL 1 | 45 1
091 STO I | 44 25
092 RCL (i) | 45 24
093 x=0 | 43 20
094 RTN | 43 32
095 0 | 0
096 STO 2 | 44 2
097 SF 1 | 43, 4, 1
098 LBL 9 | 42,21, 9
099 GSB .0 | 32 .0
100 6 | 6
101 - | 30
102 1 | 1
103 TEST 5 | 43,30, 5
104 STO+2 | 44,40, 2
105 GSB .0 | 32 .0
106 7 | 7
107 - | 30
108 1 | 1
109 TEST 5 | 43,30, 5
110 STO-2 | 44,30, 2
111 RCL 2 | 45 2
112 x=0 | 43 20
113 RTN | 43 32
114 1 | 1
115 F? 1 | 43, 6, 1
116 CHS | 16
117 STO+0 | 44,40, 0
118 GTO 9 | 22 9
119 LBL .0 | 42,21,.0
120 RCL 0 | 45 0
121 F? 0 | 43, 6, 0
122 GTO E | 22 15
123 STO I | 44 25
124 RCL (i) | 45 24
125 RTN | 43 32
126 LBL E | 42,21,15
127 1 | 1
128 0 | 0
129 / | 10
130 STO I | 44 25
131 FRAC | 42 44
132 1 | 1
133 0 | 0
134 * | 20
135 LSTx | 43 36
136 x<>y | 34
137 - | 30
138 10^x | 13
139 RCL (i) | 45 24
140 x<>y | 34
141 / | 10
142 FRAC | 42 44
143 1 | 1
144 0 | 0
145 * | 20
146 INT | 43 44
147 RTN | 43 32