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  • Re: Rot13 for DOS

    From Kerr-Mudd, John@admin@nospicedham.127.0.0.1 to comp.os.msdos.programmer,comp.lang.asm.x86,alt.lang.asm on Sat Nov 18 11:10:20 2023
    From Newsgroup: alt.lang.asm

    On Fri, 27 Jan 2023 13:30:13 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    On Fri, 27 Jan 2023 09:57:22 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    On Wed, 25 Jan 2023 17:02:43 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    []
    Kerr-Mudd, John wrote:
    Finally, a rot13 program for DOS that's smaller than the standard version
    with jumps:

    []
    'Better' still use C3 (embedded 'ret') to reduce prog to 45 bytes.
    []

    One that works even if the rot amount isn't 13 (ie the older version
    didn't!) also 45 bytes:

    u 100 l2D
    16AD:0100 BA E6 0D mov dx,0DE6
    16AD:0103 B4 3F mov ah,3F
    16AD:0105 B5 C3 mov ch,C3
    16AD:0107 CD 21 int 21
    16AD:0109 91 xchg ax,cx
    16AD:010A E3 FA jcxzw 0106

    16AD:010C 89 D6 mov si,dx
    16AD:010E 51 push cx

    16AD:010F AC lodsb
    16AD:0110 24 DF and al,DF
    16AD:0112 2C 41 sub al,41
    16AD:0114 2C 1A sub al,1A
    16AD:0116 18 E4 sbb ah,ah
    16AD:0118 00 F0 add al,dh
    16AD:011A D6 salc
    16AD:011B 21 D0 and ax,dx
    16AD:011D 00 E0 add al,ah
    16AD:011F 00 64 FF add [si-01],ah
    16AD:0122 E2 EB loopw 010F

    16AD:0124 59 pop cx
    16AD:0125 43 inc bx
    16AD:0126 B4 40 mov ah,40
    16AD:0128 CD 21 int 21
    16AD:012A 4B dec bx
    16AD:012B EB D6 jmp 0103

    d 100 l2D
    16AD:0100 BA E6 0D B4-3F B5 C3 CD-21 91 E3 FA-89 D6 51 AC ....?...!.....Q. 16AD:0110 24 DF 2C 41-2C 1A 18 E4-00 F0 D6 21-D0 00 E0 00 $.,A,......!.... 16AD:0120 64-FF E2 EB 59-43 B4 40 CD-21 4B EB D6 d...YC.@.!K..
    q



    And a version that allows the rot amount as a parameter in 64 bytes:
    example usage:
    rot 3<input.txt

    u 100 l40
    16AD:0100 BA E6 0D mov dx,0DE6
    16AD:0103 BE 82 00 mov si,0082
    16AD:0106 AD lodsw
    16AD:0107 2D 30 30 sub ax,3030
    16AD:010A 72 04 jb 0110
    16AD:010C 86 E0 xchg ah,al
    16AD:010E D5 0A aad 0A
    16AD:0110 3C 00 cmp al,00
    16AD:0112 72 02 jb 0116
    16AD:0114 88 C6 mov dh,al

    16AD:0116 B4 3F mov ah,3F
    16AD:0118 B5 C3 mov ch,C3
    16AD:011A CD 21 int 21
    16AD:011C 91 xchg ax,cx
    16AD:011D E3 FA jcxzw 0119

    16AD:011F 89 D6 mov si,dx
    16AD:0121 51 push cx

    16AD:0122 AC lodsb
    16AD:0123 24 DF and al,DF
    16AD:0125 2C 41 sub al,41
    16AD:0127 2C 1A sub al,1A
    16AD:0129 18 E4 sbb ah,ah
    16AD:012B 00 F0 add al,dh
    16AD:012D D6 salc
    16AD:012E 21 D0 and ax,dx
    16AD:0130 00 E0 add al,ah
    16AD:0132 00 44 FF add [si-01],al
    16AD:0135 E2 EB loopw 0122

    16AD:0137 59 pop cx
    16AD:0138 43 inc bx
    16AD:0139 B4 40 mov ah,40
    16AD:013B CD 21 int 21
    16AD:013D 4B dec bx
    16AD:013E EB D6 jmp 0116

    d 100 l40
    16AD:0100 BA E6 0D BE-82 00 AD 2D-30 30 72 04-86 E0 D5 0A .......-00r..... 16AD:0110 3C 00 72 02-88 C6 B4 3F-B5 C3 CD 21-91 E3 FA 89 <.r....?...!.... 16AD:0120 D6 51 AC 24-DF 2C 41 2C-1A 18 E4 00-F0 D6 21 D0 .Q.$.,A,......!. 16AD:0130 00 E0 00 44-FF E2 EB 59-43 B4 40 CD-21 4B EB D6 ...D...YC.@.!K..
    q
    --
    Bah, and indeed Humbug.

    --- Synchronet 3.21d-Linux NewsLink 1.2
  • From Kerr-Mudd, John@admin@nospicedham.127.0.0.1 to comp.os.msdos.programmer,comp.lang.asm.x86,alt.lang.asm on Sat Nov 18 16:16:14 2023
    From Newsgroup: alt.lang.asm

    On Sat, 18 Nov 2023 11:10:20 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:



    And a version that allows the rot amount as a parameter in 64 bytes:
    example usage:
    rot 3<input.txt

    u 100 l40

    Bah, I knew I shouldn't have posted so soon:


    16AD:0100 BA E6 0D mov dx,0DE6
    Instead of

    16AD:0103 BE 82 00 mov si,0082
    16AD:0106 AD lodsw
    use:
    16AD:0103 A1 82 00 mov ax,[0082]

    (and adjust everything else up 1)

    16AD:0107 2D 30 30 sub ax,3030
    16AD:010A 72 04 jb 0110
    16AD:010C 86 E0 xchg ah,al
    16AD:010E D5 0A aad 0A
    16AD:0110 3C 00 cmp al,00
    16AD:0112 72 02 jb 0116
    16AD:0114 88 C6 mov dh,al

    16AD:0116 B4 3F mov ah,3F
    16AD:0118 B5 C3 mov ch,C3
    16AD:011A CD 21 int 21
    16AD:011C 91 xchg ax,cx
    16AD:011D E3 FA jcxzw 0119

    16AD:011F 89 D6 mov si,dx
    16AD:0121 51 push cx

    16AD:0122 AC lodsb
    16AD:0123 24 DF and al,DF
    16AD:0125 2C 41 sub al,41
    16AD:0127 2C 1A sub al,1A
    16AD:0129 18 E4 sbb ah,ah
    16AD:012B 00 F0 add al,dh
    16AD:012D D6 salc
    16AD:012E 21 D0 and ax,dx
    16AD:0130 00 E0 add al,ah
    16AD:0132 00 44 FF add [si-01],al
    16AD:0135 E2 EB loopw 0122

    16AD:0137 59 pop cx
    16AD:0138 43 inc bx
    16AD:0139 B4 40 mov ah,40
    16AD:013B CD 21 int 21
    16AD:013D 4B dec bx
    16AD:013E EB D6 jmp 0116

    d 100 l40
    16AD:0100 BA E6 0D BE-82 00 AD 2D-30 30 72 04-86 E0 D5 0A .......-00r..... 16AD:0110 3C 00 72 02-88 C6 B4 3F-B5 C3 CD 21-91 E3 FA 89 <.r....?...!.... 16AD:0120 D6 51 AC 24-DF 2C 41 2C-1A 18 E4 00-F0 D6 21 D0 .Q.$.,A,......!. 16AD:0130 00 E0 00 44-FF E2 EB 59-43 B4 40 CD-21 4B EB D6 ...D...YC.@.!K..
    q



    --
    Bah, and indeed Humbug.

    --
    Bah, and indeed Humbug.

    --- Synchronet 3.21d-Linux NewsLink 1.2
  • From Kerr-Mudd, John@admin@nospicedham.127.0.0.1 to comp.os.msdos.programmer,comp.lang.asm.x86,alt.lang.asm on Sat Nov 18 22:19:55 2023
    From Newsgroup: alt.lang.asm

    On Sat, 18 Nov 2023 11:10:20 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    On Fri, 27 Jan 2023 13:30:13 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    On Fri, 27 Jan 2023 09:57:22 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    On Wed, 25 Jan 2023 17:02:43 +0000
    "Kerr-Mudd, John" <admin@nospicedham.127.0.0.1> wrote:

    []
    Kerr-Mudd, John wrote:
    Finally, a rot13 program for DOS that's smaller than the standard version
    with jumps:

    []
    'Better' still use C3 (embedded 'ret') to reduce prog to 45 bytes.
    []

    One that works even if the rot amount isn't 13 (ie the older version
    didn't!) also 45 bytes:

    u 100 l2D
    16AD:0100 BA E6 0D mov dx,0DE6
    16AD:0103 B4 3F mov ah,3F
    16AD:0105 B5 C3 mov ch,C3
    16AD:0107 CD 21 int 21
    16AD:0109 91 xchg ax,cx
    16AD:010A E3 FA jcxzw 0106

    16AD:010C 89 D6 mov si,dx
    16AD:010E 51 push cx

    16AD:010F AC lodsb
    16AD:0110 24 DF and al,DF
    16AD:0112 2C 41 sub al,41
    16AD:0114 2C 1A sub al,1A
    16AD:0116 18 E4 sbb ah,ah
    16AD:0118 00 F0 add al,dh
    16AD:011A D6 salc
    16AD:011B 21 D0 and ax,dx
    16AD:011D 00 E0 add al,ah

    16AD:011F 00 64 FF add [si-01],ah
    Oh bother, make that al:
    16AD:011F 00 44 FF add [si-01],al

    16AD:0122 E2 EB loopw 010F

    16AD:0124 59 pop cx
    16AD:0125 43 inc bx
    16AD:0126 B4 40 mov ah,40
    16AD:0128 CD 21 int 21
    16AD:012A 4B dec bx
    16AD:012B EB D6 jmp 0103

    d 100 l2D
    16AD:0100 BA E6 0D B4-3F B5 C3 CD-21 91 E3 FA-89 D6 51 AC ....?...!.....Q. 16AD:0110 24 DF 2C 41-2C 1A 18 E4-00 F0 D6 21-D0 00 E0 00 $.,A,......!.... 16AD:0120 64-FF E2 EB 59-43 B4 40 CD-21 4B EB D6 d...YC.@.!K..
    -----------^44

    q



    (It happens to work, so passes my test but iff rot13)
    --
    Bah, and indeed Humbug.

    --- Synchronet 3.21d-Linux NewsLink 1.2