.model tiny
.code
org 100h
Start:
; Comment out for error checking

smov macro x,y
  push y
  pop x
endm

LineFeed macro
   cmp ax,0a0dh
endm

Zeta0 = 6d72h
Zeta = 6e71h
Zeta2 = 4b60h

Off100:

db 'ENC.COM.'
db 'ABC'      ; this says how far it is to the end from after the 'C'

LineFeed

       and ax,3030h
       and ax,4040h   ; set ax=0
       smov dx,ax     ; set dx=0

       sub ax,Zeta0
       sub ax,Zeta0
       sub ax,-(offset Jmp2)-Zeta0-Zeta0
       smov di,ax
       smov si,dx
       dec si
       xor [di],si
;       sub al,Jmp2-Jmp1
;       smov di,ax
;       smov si,dx
;       and [di],si
;; Want SI=00EB   (jmp $+2)
;       smov ax,dx
;       sub al,70h
;       xor al,0ebh xor -70h
;       smov si,ax
;       xor [di],si

       smov ax,dx

       sub ax,Zeta
       sub ax,Zeta

       push ax

       sub ax,-(offset udata)-Zeta-Zeta  ; adjust later so ax=udata
       smov cx,ax
       sub ax,7021h
       sub ax,6021h
       sub ax,63h-(7021h+6021h)   ; ax-=0063h
       smov bp,ax

       LineFeed

       pop ax

       sub ax,-(offset DirectPoke)-Zeta-Zeta  ; adjust so ax=DirectPoke
       smov di,ax
       push di
       smov si,dx     ; si=0
       and [di],si
       inc di
       inc di
       and [di],si
       inc di
       inc di
       and [di],si
       inc di
       inc di
       and [di],si
       inc di
       inc di
       and [di],si


       pop di         ; direct poke area is zero
; want si=E4D0
       smov ax,dx     ; ax=0
       sub ax,Zeta2  ; ax=D1D1
       xor ax,(-Zeta2) xor 0e4d0h  ; ax=e4d0
       smov si,ax
       xor [di],si
       inc di
       inc di
       xor [di],si
       inc di
       inc di
       xor [di],si
       inc di
       inc di
       xor [di],si
       inc di
       inc di
; now want si=e008     ; ax=e4d0
       sub ax,217eh
       xor ax,0e008h xor (0e4d0h-217eh)   ; ax=e008
       smov si,ax
       xor [di],si
       smov di,cx
       jz FlushPref
       jnz FlushPref
       db 13,10,'COMT_is_copyright_Alex_Pruss.',13,10
FlushPref:
Top:
       smov ax,dx
       xor ax,[bp+063h]
       inc bp
       inc bp
;       push ax
;       sub al,'Z'
;       pop ax
       cmp al,'Z'
       jz DoneJ
;       push ax
;       sub ax,0a0dh
;       pop ax
       cmp ax,0a0dh
       jz HandleNewLine

       sub ax,'AA'   ; OK, now want AL+=AH>>4

DirectPoke: db 0dh,0ah,'Good-d' ; shr ah,1  four times--D0E4
            db 'ay'       ; add al,ah--08E0
                          ; al=right value


       smov si,dx
       and [di],si        ; set to 0
       smov si,ax
       xor [di],si        ; set to al
       inc di
Pos:
       db 75h    ; jnz (NZ IS set)

Jmp2:
       db not (Top-Pos-2)   ; just negate this
       db 'Hi,Howdy??'
HandleNewLine:
       inc dx
       dec dx
J0:
       db 74h   ; jz (of course Z as DX=0 permanently)

Enc macro Val
    db 'A'+((Val) and 0fh)
    db 'A'+(((Val) shr 4) and 0fh)
endm
udata:
       Enc (Top-(J0+2))
DoneJ=$-1
;
;       Enc 0C3h       ; ret
;       db 'Z'
;
;       db 'ILAAME'        ; B8 00 4C  (mov ax,4c)
;       db 'NM','BC'       ; int 21h
;       db 'Z'
;
;0123456789ABCDEF
;ABCDEFGHIJKLMNOP

end Start