In 86-DOS, the HEX2BIN.COM file is 483 bytes in length: HEX2BIN COM 483 04-18-81 The HEX2BIN.COM file's contents are as follows (we used the original 86-DOS DEBUG program to create this ASCII dump): Offst 0 1 2 3 4 5 6 7 8 9 A B C D E F 0000 BF 65 00 82 3D 20 75 05 BE 6B 02 A4 A5 B1 04 C7 ?e..= u.>k.$%1.G 0010 06 E3 02 00 FF BE 6D 00 AC 3C 20 74 31 C6 06 E7 .c...>m.,< t1F.g 0020 02 00 3C 2B 74 09 3C 2D 75 06 C6 06 E7 02 01 AC ..<+t.<-u.F.g.., 0030 E8 D0 00 72 19 33 DB D3 E3 0A D8 AC E8 C4 00 73 hP.r.3[Sc.X,hD.s 0040 F6 F6 06 E7 02 FF 74 02 F7 DB 89 1E E3 02 BA F7 vv.g..t.w[..c.:w 0050 06 D3 EA 8C D8 03 D0 B4 26 CD 21 8E C2 26 8B 0E .Sj.X.P4&M!.B&.. 0060 06 00 89 0E E5 02 33 C0 8B F8 8B E8 D1 E9 F3 AB ....e.3@.x.hQis+ 0070 B4 0F BA 5C 00 CD 21 0A C0 75 51 C6 06 7C 00 00 4.:\.M!.@uQF.|.. 0080 C7 06 6A 00 00 04 BA E8 02 B4 1A CD 21 B4 14 BA G.j...:h.4.M!4.: 0090 5C 00 BE E8 06 E8 43 00 3C 3A 75 F9 E8 51 00 8A \.>h.hC.<:uyhQ.. 00A0 C8 B5 00 E3 7D E8 48 00 8A F8 E8 43 00 8A D8 03 H5.c}hH..xhC..X. 00B0 1E E3 02 8B FB E8 38 00 3B 3E E5 02 73 17 E8 2F .c..{h8.;>e.s.h/ 00C0 00 AA 3B FD 76 02 8B EF E2 EE EB C9 BA 97 02 B4 .*;}v..obnkI:..4 00D0 09 CD 21 CD 20 BA A6 02 E9 43 00 81 FE E8 06 75 .M!M :&.iC..~h.u 00E0 09 CD 21 3C 01 74 34 BE E8 02 AC 3C 1A 74 33 C3 .M!<.t4>h.,<.t3C 00F0 E8 20 00 8A D8 E8 1B 00 D0 E3 D0 E3 D0 E3 D0 E3 h ..Xh..PcPcPcPc 0100 0A C3 C3 2C 30 72 FB 3C 0A 72 06 2C 07 72 F3 3C .CC,0r{<.r.,.rs< 0110 10 F5 C3 E8 C5 FF E8 EA FF 73 F7 BA 71 02 B4 09 .uChE.hj.sw:q.4. 0120 CD 21 FF 36 70 00 C7 06 65 00 43 4F C6 06 67 00 M!.6p.G.e.COF.g. 0130 4D BA 5C 00 B4 16 CD 21 0A C0 75 29 33 C0 A3 7D M:\.4.M!.@u)3@#} 0140 00 A3 7F 00 40 A3 6A 00 33 D2 1E 06 1F B4 1A CD .#..@#j.3R...4.M 0150 21 1F 8B CD B4 28 BA 5C 00 CD 21 8F 06 70 00 B4 !..M4(:\.M!..p.4 0160 10 CD 21 CD 20 BA CF 02 E9 64 FF 48 45 58 43 4F .M!M :O.id.HEXCO 0170 4D 45 72 72 6F 72 20 69 6E 20 48 45 58 20 66 69 MError in HEX fi 0180 6C 65 2D 2D 63 6F 6E 76 65 72 73 69 6F 6E 20 61 le--conversion a 0190 62 6F 72 74 65 64 24 46 69 6C 65 20 6E 6F 74 20 borted$File not 01A0 66 6F 75 6E 64 24 41 64 64 72 65 73 73 20 6F 75 found$Address ou 01B0 74 20 6F 66 20 72 61 6E 67 65 2D 2D 63 6F 6E 76 t of range--conv 01C0 65 72 73 69 6F 6E 20 61 62 6F 72 74 65 64 24 44 ersion aborted$D 01D0 69 73 6B 20 64 69 72 65 63 74 6F 72 79 20 66 75 isk directory fu 01E0 6C 6C 24 ll$ It's quite easy to see that the following bytes which we found on the IBM PC DOS 1.00 diskette match perfectly with those in the HEX2BIN.COM program above (for offsets 0C2h through 1E2h): Offst 0 1 2 3 4 5 6 7 8 9 A B C D E F 56C0 3B FD 76 02 8B EF E2 EE EB C9 BA 97 02 B4 ;.v........... 56D0 09 CD 21 CD 20 BA A6 02 E9 43 00 81 FE E8 06 75 ..!. ....C.....u 56E0 09 CD 21 3C 01 74 34 BE E8 02 AC 3C 1A 74 33 C3 ..!<.t4....<.t3. 56F0 E8 20 00 8A D8 E8 1B 00 D0 E3 D0 E3 D0 E3 D0 E3 . .............. 5700 0A C3 C3 2C 30 72 FB 3C 0A 72 06 2C 07 72 F3 3C ...,0r.<.r.,.r.< 5710 10 F5 C3 E8 C5 FF E8 EA FF 73 F7 BA 71 02 B4 09 .........s..q... 5720 CD 21 FF 36 70 00 C7 06 65 00 43 4F C6 06 67 00 .!.6p...e.CO..g. 5730 4D BA 5C 00 B4 16 CD 21 0A C0 75 29 33 C0 A3 7D M.\....!..u)3..} 5740 00 A3 7F 00 40 A3 6A 00 33 D2 1E 06 1F B4 1A CD ....@.j.3....... 5750 21 1F 8B CD B4 28 BA 5C 00 CD 21 8F 06 70 00 B4 !....(.\..!..p.. 5760 10 CD 21 CD 20 BA CF 02 E9 64 FF 48 45 58 43 4F ..!. ....d.HEXCO 5770 4D 45 72 72 6F 72 20 69 6E 20 48 45 58 20 66 69 MError in HEX fi 5780 6C 65 2D 2D 63 6F 6E 76 65 72 73 69 6F 6E 20 61 le--conversion a 5790 62 6F 72 74 65 64 24 46 69 6C 65 20 6E 6F 74 20 borted$File not 57A0 66 6F 75 6E 64 24 41 64 64 72 65 73 73 20 6F 75 found$Address ou 57B0 74 20 6F 66 20 72 61 6E 67 65 2D 2D 63 6F 6E 76 t of range--conv 57C0 65 72 73 69 6F 6E 20 61 62 6F 72 74 65 64 24 44 ersion aborted$D 57D0 69 73 6B 20 64 69 72 65 63 74 6F 72 79 20 66 75 isk directory fu 57E0 6C 6C 24 ll$ EOF. Created by Daniel B. Sedory, March 22, 2015.