VLX Compilation & Verification Guide

How to compile AutoLISP source files to VLX and verify against the original ConstructiVision binaries.

Note

Why Compile Instead of Decompile?

Unlike InstallShield (which has isDcc), there is no free, open-source VLX/FAS decompiler. The Visual LISP bytecode format is proprietary and protected. However, since we have the original LSP source files, we can:

  1. Compile source → FAS → VLX

  2. Compare against original VLX

  3. Verify the VLX contains what we expect

Prerequisites

Component

Version

Purpose

AutoCAD

2000 (R15) or later

Visual LISP compiler

Source Files

src/x86/v3_60/v3.60/*.lsp

Original LISP source

Original VLX

src/x86/v3_60/v3.60/Csv.VLX

Binary to verify against

AutoCAD 2000 Notes:

  • Includes Visual LISP IDE (VLIDE)

  • Compiler produces FAS files compatible with R15+ format

  • Original ConstructiVision v3.60 was compiled with this version

Compilation Methods

Method 1: Visual LISP IDE (GUI)

Best for first-time setup and understanding the process.

1. Open AutoCAD 2000
2. Command: VLIDE
   (Opens Visual LISP IDE)

3. File → Make Application → New Application Wizard

4. Wizard Steps:
   a. Application Name: CSV
   b. Application Location: Choose output folder
   c. Application Options:
      - ☑ Separate Namespace (isolates from global LISP)
      - ☑ ActiveX Support (if using COM/ActiveX)
      - ☑ Protected (encrypts bytecode)
   d. LISP Files to Include: Add all *.lsp files
   e. Resource Files: Add *.dcl dialog files
   f. Build

5. Output: CSV.VLX

Method 2: Command Line Compilation (Single File)

Compile individual LSP files to FAS for testing.

;; In AutoCAD command line or VLIDE Console

;; Compile single file to FAS
(vlisp-compile 'st "C:/Users/chadw/Constructivision/src/x86/v3_60/v3.60/panel.lsp")
;; Output: panel.fas in same directory

;; Compilation modes:
;;   'st  = Standard (smallest, optimized)
;;   'lsm = List assembly (debugging)
;;   'lsa = List assembly with source

Method 3: Batch Compile All LSP Files

Compile all LSP files in a directory to FAS.

;; Save this as compile-all.lsp and load it

(defun c:COMPILE-ALL ( / lsp-dir files f)
  (setq lsp-dir "C:/Users/chadw/Constructivision/src/x86/v3_60/v3.60/")
  (setq files (vl-directory-files lsp-dir "*.lsp" 1))
  
  (foreach f files
    (princ (strcat "\nCompiling: " f "..."))
    (vl-file-compile (strcat lsp-dir f))
    (princ " Done.")
  )
  
  (princ (strcat "\n\nCompiled " (itoa (length files)) " files."))
  (princ)
)

;; Run with: COMPILE-ALL

Method 4: PRV Project File

For repeatable builds, create a project file.

Create csv.prv:

;; ConstructiVision Project File
;; AutoCAD 2000 Visual LISP

:application CSV
:output-dir "C:/Users/chadw/Constructivision/build/vlx/"

:fas-files (
  "csv"
  "enable"
  "setvars"
  "panel"
  "drawpan"
  ;; ... list all 109 modules
)

:dcl-files (
  "wall_dlg"
  "panel_dlg"
  ;; ... list all DCL files
)

:options (
  :protected T
  :separate-namespace T
  :active-x T
)

Build from PRV:

(vl-load-project "C:/Users/chadw/Constructivision/src/x86/v3_60/csv.prv")
(vl-make-app)

Verification Methods

Hash Comparison (Simple but Limited)

# Hash original VLX
Get-FileHash "src\x86\v3_60\v3.60\Csv.VLX" -Algorithm SHA256

# Hash newly compiled VLX
Get-FileHash "build\vlx\Csv.VLX" -Algorithm SHA256

⚠ WARNING: Hashes will likely NOT match because:

  • Timestamps embedded in FAS bytecode

  • Compiler version differences

  • Protection key variations

  • Build order differences

Hash matching is useful for detecting changes between your own builds, not for verifying against the original.

Size Comparison

Rough sanity check - compiled VLX should be similar size.

# Original
(Get-Item "src\x86\v3_60\v3.60\Csv.VLX").Length
# 1,103,600 bytes

# Compiled
(Get-Item "build\vlx\Csv.VLX").Length
# Should be within ~10% of original

Behavioral Testing

Load both VLX files and test identical functionality.

;; Test 1: Load original, run commands, note behavior
(load "Csv.VLX")
(c:CSV)      ;; Main entry point
(c:PANEL)    ;; Panel command
;; Document results

;; Test 2: Restart AutoCAD, load compiled, compare
(load "Csv_compiled.VLX")
(c:CSV)
(c:PANEL)
;; Should behave identically

Source File Inventory

What We Have

# Count LSP files in v3.60
Get-ChildItem "src\x86\v3_60\v3.60" -Filter "*.lsp" -Recurse | Measure-Object
# Expected: ~80-100 files

# Count DCL files
Get-ChildItem "src\x86\v3_60\v3.60" -Filter "*.dcl" -Recurse | Measure-Object
# Expected: ~40 files

What the VLX Contains

The original Csv.VLX contains 109 FAS modules (from binary analysis):

CSV, ENABLE, SETVARS, UPDVAR, ERR, WARNING,
PROJECT, PJ_NAME, NEW, DWGNEW, DWGOLD,
PANEL, DRAWPAN, MAKEPAN, INSPANEL, FINPAN, RENPAN, PANATT,
BP_DLG, FH_DLG, FS_DLG, FV_DLG,
PP_DLG, SLAB_DLG, WALL_DLG, RO_DLG,
CH_DLG, DL_DLG, DR_DLG, MP_DLG, OPENING,
... (see csv-vlx-binary-notes.md for full list)

Gap Analysis

Compare source files to VLX modules:

# List LSP basenames
$lspFiles = Get-ChildItem "src\x86\v3_60\v3.60" -Filter "*.lsp" | 
    Select-Object -ExpandProperty BaseName | 
    ForEach-Object { $_.ToUpper() }

# Known VLX modules (from binary analysis)
$vlxModules = @("CSV", "ENABLE", "SETVARS", "PANEL", ...) # full list

# Find missing source
$vlxModules | Where-Object { $_ -notin $lspFiles }

Troubleshooting

“Function Not Defined” After Load

Cause: Missing dependent module Fix: Check load order in original csv.lsp entry point

Compiled VLX Much Smaller

Cause: Not all LSP files included Fix: Cross-reference with 109-module list from VLX analysis

“Protection Error” on Load

Cause: Protection mode mismatch Fix: Ensure :protected T matches original if distributing

Functions Work Differently

Cause: Compiler version differences or missing includes Fix: Test in AutoCAD 2000 (same as original)

Decompilation Reality Check

Why No Decompiler Exists

Aspect

InstallShield (.ins)

Visual LISP (.fas/.vlx)

Format

Documented bytecode

Proprietary encrypted

Protection

None

:protected option

Decompiler

isDcc v1.22

None (free/open-source)

Commercial

N/A

vlxfas2lsp.com (paid service)