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Active Forums => QB64 Discussion => Topic started by: EricE on February 28, 2020, 04:05:08 am

Title: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 28, 2020, 04:05:08 am
I am using the ABSOLUTE function to execute machine code that has been placed in an array.

QB64 is reporting this runtime error:
x86 Error, Unknown Opcode (92)

Opcode 92 is one of the instructions in my machine code array.
The mnemonic for this opcode is:

XCHG    DX,AX

Why would QB64 report that the opcode for this instruction is unknown?

Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: luke on February 28, 2020, 04:08:25 am
Because the x86 emulation is really half-assed, and basically has had just enough work done on it to allow some standard mouse routines from the QB era to work.
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 28, 2020, 04:18:28 am
Thank you Luke.
I will try to find a work around.
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: FellippeHeitor on February 28, 2020, 04:23:43 am
Yeah, no low level in the basic side. You’d need to dive into c for that.

What did you intend to do with machine code?
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 28, 2020, 01:31:24 pm
The opcode 92 is contained in the source code for the QBWrite text editor, version 2.7.

This can be obtained by downloading the file obw.zip from this page:

https://qb45.org/files.php?cat=10&p=8 (https://qb45.org/files.php?cat=10&p=8)
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: FellippeHeitor on February 28, 2020, 01:40:39 pm
But what’s the machine code call supposed to do? Maybe qb64 already does it without the low level call.
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 28, 2020, 01:42:14 pm
Here is the qbwrite 2.7 source code that contains not only the 92 opcode, but the 91 and 93 opcodes as well.
The opcodes used are part of the program's mouse routine.

Code: QB64: [Select]
  1. DEFINT A-Z
  2. DIM SHARED a(9)
  3. DEF SEG = VARSEG(a(0))
  4. FOR i = 0 TO 17
  5.     READ r
  6.     POKE VARPTR(a(0)) + i, r
  8. '---------------------------- Machine Code -----------------------------------
  9. DATA &HB8,&H00,&H00:
  10. DATA &H55:
  11. DATA &H8B,&HEC:
  12. DATA &HCD,&H33:
  13. DATA &H92:
  14. DATA &H8B,&H5E,&H06:
  15. DATA &H89,&H07:
  16. DATA &H5D:
  17. DATA &HCA,&H02,&H00:
  18. '-------------------------------------------------------------------------------
  19.  
  20. SUB Mouse (cx, dx, bx)
  21.        
  22.     POKE VARPTR(a(4)), &H92 'Swap code,Get CX setup
  23.     CALL ABSOLUTE(cx, VARPTR(a(0))) 'Run Code
  24.     cx = (cx / 8) + 1 'Adjust 25x80
  25.     POKE VARPTR(a(4)), &H91 'Swap code,Get DX setup
  26.     CALL ABSOLUTE(dx, VARPTR(a(0))) 'Run Code
  27.     dx = (dx / 8) + 1 'Adjust 25x80
  28.     POKE VARPTR(a(4)), &H93 'Swap code,Get BX setup
  29.     CALL ABSOLUTE(bx, VARPTR(a(0))) 'Run Code
  30.  
  32.  
  33. SUB MousePointer (SW)
  34.        
  35.     POKE VARPTR(a(0)) + 1, SW 'Swap code,Set AX = (SW)
  36.     CALL ABSOLUTE(c, VARPTR(a(0))) 'Run Code
  37.  
  39.  

Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: FellippeHeitor on February 28, 2020, 01:45:53 pm
Adapt your code to use the new mouse features.  http://www.qb64.org/wiki/Keyword_Reference_-_By_usage#Mouse_Input: (http://www.qb64.org/wiki/Keyword_Reference_-_By_usage#Mouse_Input:)

All functions are prefixed with _MOUSE.
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 28, 2020, 06:13:32 pm
Here are the subroutines using QB64's mouse features.

Code: QB64: [Select]
  1. SUB Mouse (cx, dx, bx)
  2.  
  3.     mi = _MOUSEINPUT
  4.     cx = _MOUSEY ' Qbwrite's horizontal column number
  5.     dx = _MOUSEX ' Qbwrite's vertical row number
  6.  
  7.     bx = 0
  8.     IF _MOUSEBUTTON(1) THEN bx = bx OR &H1 ' Left mouse button
  9.     IF _MOUSEBUTTON(2) THEN bx = bx OR &H2 ' Right mouse button
  10.     IF _MOUSEBUTTON(3) THEN bx = bx OR &H4 ' Center or scroll button
  11.  
  12.  
  14.  
  15. SUB MousePointer (SW)
  16.  
  18.  
  19.     SELECT CASE SW
  20.         CASE 0 ' Initialize mouse
  21.             ' In QB64 nothing to do
  22.         CASE 1 ' Show mouse cursor
  23.             _MOUSESHOW
  24.         CASE 2 ' Hide mouse cursor
  25.             _MOUSEHIDE
  26.         CASE 3 ' Get mouse position
  27.             ' Done in Mouse subroutine
  28.     END SELECT
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 28, 2020, 11:44:46 pm
Waiting for the _MOUSEINPUT function to return zero

Code: QB64: [Select]

might not be required in the above code.
Title: Re: QB64 x86 Error, Unknown Opcode (92)
Post by: EricE on February 29, 2020, 01:44:46 am
The mouse machine code is explained in detail in this file:
qmouse.zip by Robert Wolf
which is available for download from the web page:
https://qb45.org/files.php?cat=10&p=8 (https://qb45.org/files.php?cat=10&p=8)

This is only to understand the operation of the original code, as it will not run in QB64 due to some opcodes not being emulated.
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