An EMS tester/information viewer

comment <----------------------------------------------------
 This is an EMS memory tester
 Type EMSINFO at the prompt

    Version:  1.00
     Author:  Ben Lunt
   Modified:  11 Jan 2001
  Assembler:  NBASM

   -= I cleaned it up a bit, and made it assemble with NBASM =-


.model tiny
           mov  ah,01h                  ; turn off cursor
           mov  ch,20h                  ; bit number 5
           int  10h                     ;
           mov  si,offset StartIt       ; print start string
           call prtstring               ;
           call ChkEMS                  ; see if EMS is present
           jnc  short ItsThere
           mov  si,offset NoneMsg
           call prtstring
           jmp  AllDone

ItsThere:  mov  si,offset InMsg
           call prtstring

           mov  ah,46h                  ; get EMS version
           int  67h
           mov  ah,al
           and  ah,00001111b            ; minor version
           shr  al,04h                  ; major version
           or   ax,3030h                ; make ascii
           mov  Major,al
           mov  Minor,ah
           mov  si,offset Version
           call prtstring

           mov  si,offset PageMsg       ; page frame message
           call prtstring
           mov  ah,41h                  ; get page frame address
           int  67h
           mov  ax,bx                   ; This is the page frame base
           call prthex

           mov  si,offset TotalMsg      ; Total memory message
           call prtstring
           mov  ah,42h
           int  67h
           xor  eax,eax
           mov  ax,dx
           xor  edx,edx
           mov  ecx,4000h
           mul  ecx
           call prtdec

           mov  si,offset FreeMsg       ; available memory message
           call prtstring
           xor  eax,eax
           mov  ax,bx
           mov  ebx,4000h
           mul  ebx
           call prtdec

           mov  ah,43h                  ; allocate pages
           mov  bx,02h                  ; get 2 pages (32K)
           int  67h
           or   ah,ah                   ; was there an error?
           jne  short Error1            ;
           mov  EMPhandle,dx            ; no, save handle

           mov  ax,4400h                ; map memory - first EMS page
           xor  bx,bx                   ; want this part of my memory
           mov  dx,EMPhandle            ; assigned to this handle
           int  67h
           or   ah,ah                   ; was there an error?
           jnz  short Error2            ;
           mov  ax,4401h                ; map memory
           mov  bx,01h
           int  67h
           or   ah,ah                   ; was there an error?
           jnz  short Error2            ; yes, so handle

           mov  ah,41h                  ; get page frame address
           int  67h
           or   ah,ah                   ; was there an error?
           jnz  short Error3            ; yes, so handle
           mov  es,bx                   ; make page frame addressable

           mov  si,offset FillMsg
           call prtstring
           mov  cx,910                  ; 36-character message fits this
           cld                          ;   many times in 32K (32768 bytes)
           xor  di,di                   ; start of page buffer
InLoop:    push cx
           mov  si,offset TestMsg
           mov  cx,09                   ; length of message (36/4)
           call IncIt                   ; inc the counter in the 
           pop  cx                      ;   test message
           loop InLoop
           mov  al,0FFh                 ; put ending flag
           stosb                        ;

           mov  si,offset ReadMsg       ;
           call prtstring               ;
           xor  si,si                   ;
           push ds                      ; set up addressing
           push es                      ;
           pop  ds                      ;
OutLoop:   call prtstring               ; print back the test message
           cmp  byte [si],0FFh          ;  that was stuffed in to
           jne  short OutLoop           ;   the memory
           pop  ds                      ;

           mov  ah,45h                  ; release EMS handle
           mov  dx,EMPhandle            ; this handle
           int  67h                     ;
           or   ah,ah                   ; was there an error
           je   short AllDone
           mov  si,offset EMsg4
           jmp  short PrntErr
Error1:    mov  si,offset EMsg1
           jmp  short PrntErr
Error2:    mov  si,offset EMsg2
           jmp  short PrntErr
Error3:    mov  si,offset EMsg3
PrntErr:   call prtstring
AllDone:   mov  ah,01h                  ; turn on cursor
           mov  cx,0607h                ; start = 6   finish = 7
           int  10h                     ;
           mov  si,offset crlf
           call prtstring

ChkEMS     proc near uses ax bx dx es

           mov  dx,offset EMSName       ; device driver name
           mov  ax,3D00h                ; open device-access/file sharing mode
           int  21h
           jc   short NotThere2
           mov  bx,ax                   ; put handle in proper place
           mov  ax,4407h                ; IOCTL  -  get output status
           int  21h
           jc   short NotThere1
           cmp  al,0FFh
           jne  short NotThere1
           mov  ah,3Eh                  ; close device
           int  21h
           clc                          ; set for no error
           jnc  short Done
NotThere1: mov  ah,3Eh                  ; close device
           int  21h
NotThere2: stc
Done:      ret
ChkEMS     endp

IncIt      proc near uses si
           mov  si,offset Count
           add  si,03h
IncIt1:    inc  byte [si]
           cmp  byte [si],58        ; out of number range?
           jne  short IncIt2        ; no, so continue
           mov  byte [si],48        ; reset to zero
           dec  si
           cmp  byte [si],32        ; filled in yet?
           jne  short IncIt1
           mov  byte [si],48        ; reset to zero
           jmp  short IncIt1
IncIt2:    ret
IncIt      endp

prtstring  proc near uses ax
Ps1:       mov  dl,[si]                 ; Get character
           inc  si                      ; Point to next one
           or   dl,dl                   ; End of string?
           jz   short ps2               ; Yes, so exit
           mov  ah,02h                  ; Output a character
           int  21h
           jmp  short Ps1               ; Keep doing it
Ps2:       ret
prtstring  endp

prtdec     proc near uses eax ecx edx bx di
           xor  bx,bx                   ; number of chars to print
           mov  cx,0FFFFh               ; Ending flag
           push cx
           mov  ecx,10
PD1:       xor  edx,edx
           div  ecx                     ; Divide by 10
           add  dl,30h                  ; Convert to ASCII
           push dx                      ; Store remainder
           or   eax,eax                 ; Are we done?
           jnz  short PD1               ; No, so continue
PD2:       pop  dx                      ; Character is now in DL
           cmp  dx,0FFFFh               ; Is it the ending flag?
           je   short PD3               ; Yes, so continue
           mov  ah,02
           int  21h
           inc  bx
           jmp  short PD2               ; Keep doing it
PD3:       ret
prtdec     endp

PrtHex     proc near uses ax cx dx
           mov  cx,04
PLoop:     rol  ax,04          ;
           push ax             ;
           and  al,0Fh         ;
           daa                 ;
           add  al,0F0h        ;
           adc  al,40h         ;
           mov  ah,02          ;
           mov  dl,al          ;
           int  21h            ;
           pop  ax             ;
           loop PLoop          ;
           mov  ah,02
           mov  dl,'h'
           int  21h
PrtHex     endp

StartIt     db  13,10,'EMS Info              Version 1.00'
            db  13,10,' Forever Young Software  1990-2015'
crlf        db  13,10,0
InMsg       db  13,10,'The expanded memory manager is installed.',0
NoneMsg     db  13,10,'No expanded memory manager detected!',0
Version     db  13,10,'EMS version '
Major       db  00,'.'
Minor       db  00,'.',00h
PageMsg     db  13,10,'   The page frame address:  ',0
TotalMsg    db  13,10,'    Total expanded memory:  ',0
FreeMsg     db  13,10,'Expanded memory available:  ',0

EMSName     db  'EMMXXXX0',0
EMPhandle   dw  0000h
FillMsg     db  13,10,10,'-------Performing the test---------'
            db  13,10,'  Filling expanded memory pages',0
ReadMsg     db  13,10,'  Reading expanded memory pages',13,10,0
TestMsg     db  'This is a test message   blk#:'
Count       db  '   1',13,0
EMsg1       db  13,10,'Could not allocate memory requested',0
EMsg2       db  13,10,'Error mapping memory',0
EMsg3       db  13,10,'Could not determine page frame',0
EMsg4       db  13,10,'Error releasing EMS handle',0