Experimenting Visual Basic 4 in DosBox + Windows 3.1 running on Windows 10. While I have installed SHARE.exe from MS-DOS 6.22 and it seems to run OK, it still fails to detect it.
The error I get is : "SHARE.exe must be installed in order to run Visual Basic"
I wanted to work out how the SHARE.exe detection works. I installed the Windows 3.1 SDK and tried to debug with CodeView. However I can't figure out how to set a breakpoint on MESSAGEBOX, and I can't use the keyboard shortcut to "halt" the system and break into CodeView as it seems to be passed to Windows host instead of Dosbox.
An analysis of VBIDE.dll I can find the error message:
res098:0000 ; Resource, type (8006): String table
res098:0000 ; File offset : 26CB0h Length: 0100h
res098:0000 ; Attributes (1C30): Movable Pure
res098:0000 ; Resource ID : 3143
res098:0000 ; ===========================================================================
res098:0000
res098:0000 ; Segment type: Regular
res098:0000 res098 segment para public 'RESOURCE' use16
res098:0000 assume cs:res098
res098:0000 assume es:nothing, ss:nothing, ds:nothing, fs:nothing, gs:nothing
res098:0000 a8shareExeMustB db '8SHARE.EXE must be installed in order to run Visual Basic',0
res098:003A aRecordsourcePr db '>RecordSource property of the associated data control is empty.MV'
res098:003A db 'isual Basic was not able to start up due to an invalid system con'
The VBIDE.dll is referenced in VB.exe this way:
cseg15:2EBF mov es, [bp+var_4+2]
cseg15:2EC2 mov byte ptr es:[si+1], 0
cseg15:2EC7 lea ax, [bp+var_17A]
cseg15:2ECB push ss
cseg15:2ECC push ax ; LPCSTR
cseg15:2ECD push ds
cseg15:2ECE push offset aVbideDll ; "VBIDE.DLL"
cseg15:2ED1 call sub_37E70
cseg15:2ED6 mov word_10C9DC, ax
cseg15:2ED9 or ax, ax
cseg15:2EDB jnz short loc_389CC
cseg15:2EDD push ds
cseg15:2EDE push offset aVbideDll_0 ; "VBIDE.DLL"
cseg15:2EE1 push ds
cseg15:2EE2 push offset aTheLanguageDll ; "The language DLL '%s' could not be foun"...
cseg15:2EE5 lea ax, [bp+var_27A]
I suspect this word_10C9DC location is important, and it's referenced when calling LOADSTRING (Some examples there are many more)
cseg09:269A enter 50h, 0
cseg09:269E push word_10C9DC ; HINSTANCE
cseg09:26A2 push 7D0h ; UINT
cseg09:26A5 lea ax, [bp+var_28]
cseg09:26A8 push ss
cseg09:26A9 push ax ; LPSTR
cseg09:26AA push 28h ; '(' ; int
cseg09:26AC call LOADSTRING
cseg09:26B1 push word_10C9DC ; HINSTANCE
cseg09:26B5 push [bp+arg_2] ; UINT
cseg09:26B8 lea ax, [bp+var_50]
cseg09:26BB push ss
cseg09:26BC push ax ; LPSTR
cseg09:26BD push 28h ; '(' ; int
cseg09:26BF call LOADSTRING
cseg09:26C4 lea ax, [bp+var_28]
cseg09:26C7 push ss
cseg09:26C8 push ax ; LPCSTR
cseg09:26C9 lea ax, [bp+var_50]
cseg09:26CC push ss
cseg09:26CD push ax ; LPCSTR
cseg09:26CE push [bp+arg_0] ; int
cseg09:26D1 push seg cseg04
cseg09:26D4 push offset aVbIni ; "VB.INI"
cseg09:26D7 call GETPRIVATEPROFILEINT
cseg09:26DC leave
There is a few MESSAGEBOX references:
MessageBox #1
cseg05:0EC8 push 0 ; HWND
cseg05:0ECA les bx, dword_10C1F8
cseg05:0ECE add bx, es:[bx+9Ah]
cseg05:0ED3 push es
cseg05:0ED4 push bx ; LPCSTR
cseg05:0ED5 push 0
cseg05:0ED7 push 0 ; LPCSTR
cseg05:0ED9 push 10h ; UINT
cseg05:0EDB call MESSAGEBOX
MessageBox #2
cseg15:2FE2 push 0 ; HWND
cseg15:2FE4 les bx, dword_10C1F8
cseg15:2FE8 add bx, es:[bx+9Eh]
cseg15:2FED push es
cseg15:2FEE push bx ; LPCSTR
cseg15:2FEF push seg cseg02
cseg15:2FF2 push offset byte_9EC8 ; LPCSTR
cseg15:2FF5 push 1010h ; UINT
cseg15:2FF8 call MESSAGEBOX
MessageBox #4 & 5
cseg47:297E push bp
cseg47:297F mov bp, sp
cseg47:2981 push di
cseg47:2982 push si
cseg47:2983 mov di, [bp+6]
cseg47:2986 mov es, word ptr [bp+8]
cseg47:2989 push word ptr es:[di]
cseg47:298C push word ptr es:[di+4]
cseg47:2990 push word ptr es:[di+2]
cseg47:2994 push word ptr es:[di+8]
cseg47:2998 push word ptr es:[di+6]
cseg47:299C push word ptr es:[di+0Ah]
cseg47:29A0 call MESSAGEBOX
cseg47:29A5 mov si, ax
cseg47:29A7 or si, ax
cseg47:29A9 jnz short loc_B517F
cseg47:29AB mov es, word ptr [bp+8]
cseg47:29AE and word ptr es:[di+0Ah], 0CF0Fh
cseg47:29B4 push word ptr es:[di]
cseg47:29B7 push word ptr es:[di+4]
cseg47:29BB push word ptr es:[di+2]
cseg47:29BF push word ptr es:[di+8]
cseg47:29C3 push word ptr es:[di+6]
cseg47:29C7 or word ptr es:[di+0Ah], 1010h
cseg47:29CD push word ptr es:[di+0Ah]
cseg47:29D1 call MESSAGEBOX
I couldn't work out which messagebox was displaying the message, so I replaced them all with int 3, this allowed me to break into the CodeView debugger. From this I worked out relevant MESSAGEBOX code displaying error was:
cseg47:297E push bp
cseg47:297F mov bp, sp
cseg47:2981 push di
cseg47:2982 push si
cseg47:2983 mov di, [bp+6]
cseg47:2986 mov es, word ptr [bp+8]
cseg47:2989 push word ptr es:[di]
cseg47:298C push word ptr es:[di+4]
cseg47:2990 push word ptr es:[di+2]
cseg47:2994 push word ptr es:[di+8]
cseg47:2998 push word ptr es:[di+6]
cseg47:299C push word ptr es:[di+0Ah]
cseg47:29A0 call MESSAGEBOX
However there was no xref to this section of code, the only reference I could find to this location was these push statements:
loc_B51AB:
mov ax, [bp+arg_6]
mov dx, [bp+arg_8]
mov [bp+var_A], ax
mov [bp+var_8], dx
mov ax, [bp+arg_2]
mov dx, [bp+arg_4]
mov [bp+var_6], ax
mov [bp+var_4], dx
mov ax, [bp+arg_0]
mov [bp+var_2], ax
push seg cseg47
push 297Eh
lea ax, [bp+var_C]
push ss
push ax
push ss
push ax
call sub_B4F7C
leave
retf 0Ch
sub_B5188 endp
What code set up the message box string here, and is there a way by knowing the details in resource DLL what assembly I should look for when then string is loaded.
