Vision-LLMs can now drive Windows 98 driver installs end-to-end. Claude reads installer screenshots via a VGA-to-USB capture loop, makes click decisions, and recovers from registry errors and BSODs -- all running on a Raspberry Pi 5 host attached to the retro target. As of 2026, the Voodoo3 3000 PCI install on Win98 SE succeeds at 94% with this approach, at a cost of ~$0.04 per install using a local Qwen3.6 35B model.
Editorial intro: retro-agent fleet at github.com/voidsstr/retro-agent operating 4 retro PCs
The retro-agent project runs a fleet of four period-correct PCs: a Win98 SE Voodoo3 rig, a WinXP Pentium 4 box, a DOS 6.22 486, and a Win95 Pentium MMX machine. Each node has a dedicated Raspberry Pi 5 controller connected via USB VGA capture and a USB HID emulator board that sends keyboard/mouse input.
The motivation wasn't novelty -- it was pure pain. Installing drivers on Win98 involves: 1. Boot into Windows 2. Hardware wizard finds PCI device 3. Navigate to driver INF (on floppy or CD-ROM) 4. Several dialog screens, license agreement, reboot 5. Post-reboot configuration utility 6. Potential BSOD on first driver load (common with vintage GPU drivers) 7. Registry fix, reboot, test
This process takes a human 15-30 minutes per card. Automating it with a vision-LLM saved hundreds of hours across the fleet. The first automated Voodoo3 install ran on May 3, 2025.
Why this works now: Claude vision + Qwen3 35B A3B hybrid, ~$0.04/install
Two model capabilities unlocked this in 2025:
Vision accuracy at screenshot resolution: Claude's vision model (as of 2026) handles 800x600 VGA screenshots cleanly. The 3dfx installer uses Helvetica at 9pt on a 16-color dialog -- Claude reads it correctly. Earlier vision models struggled with sub-100px dialog text; Claude 4.x and Qwen3.6 35B handle it without preprocessing.
Per Anthropic's vision documentation, Claude treats images as first-class input. The retro-agent sends a user message with an image block (base64 JPEG) and a text prompt asking what dialog is shown and what to click.
Local model economics: The Qwen3.6 35B A3B sparse model runs on a single RTX 3060 12GB at 80+ tokens/sec via llama.cpp multi-token prediction. Cost per installer session (50-80 dialog steps): $0 compute cost beyond GPU electricity. Claude fallback costs ~$0.40/install. The hybrid approach delivers ~$0.04 average.
System architecture (Pi 5 host + KVM screenshot capture + retro target)
Hardware bill of materials per node:
- Raspberry Pi 4 8GB or Pi 5 (B0899VXM8F): $80-100
- USB VGA capture dongle (UVC class, e.g. Magewell USB Capture HDMI or generic): $18
- USB HID emulator board (Digispark/Teensy with usb-keyboard firmware): $8
- USB hub (powered, for capture + HID + storage): $15
- Total per node: ~$120
The capture loop runs at 5 fps (200ms cadence) -- sufficient for dialog-driven installs that humans navigate at 5-10 seconds per screen.
Vision-LLM screenshot loop on the install wizard
The core loop runs in Python (~80 lines). Each iteration: 1. Capture a JPEG screenshot from the VGA capture device via ffmpeg/v4l2 2. Send to Qwen3.6 35B (or Claude on escalation): 'What dialog is shown? Output JSON: {action, target, value}' 3. Parse response and emit the click/keystroke via USB-HID emulator 4. Wait for screen state change (pixel hash comparison) 5. Repeat until installer exits or BSOD detected
JPEG quality is set to 90+ to preserve 9pt bitmap font OCR accuracy. Below quality 75, font rendering artifacts cause OCR errors at the Voodoo3 installer's small dialog text.
Sysfix patterns the LLM learned (vcache, MSNP32, ghost devices)
After 400+ driver install sessions, the LLM has learned to recognize and recover from Win98's most common failure patterns:
vcache corruption (20% of Voodoo3 installs): The 3dfx driver installer writes to SYSTEM.INI incorrectly on some Win98 SE builds, setting MaxFileCache=0 in the [vcache] section. Symptom: blue screen with 'Invalid VxD dynamic link' on next boot. The LLM recognizes the BSOD error code, boots to DOS mode, and patches SYSTEM.INI.
MSNP32.DLL missing (15% of Audigy SE driver installs): The Creative Audigy SE installer calls MSNP32.DLL during setup, which is absent on minimal Win98 installs without networking components. The LLM now pre-checks C:/Windows/System/MSNP32.DLL before running the installer and copies it from the Win98 cab cache if missing.
Ghost devices (10% of all installs): Device Manager sometimes shows phantom device entries from previous failed installs. The LLM opens Device Manager, enables 'Show hidden devices' via Ctrl+Shift+click, and uninstalls ghost entries before re-running the driver.
Registry path mismatch (Voodoo3 6% failure mode): The Voodoo3 3000 INF creates a registry path under HKLM/System/CurrentControlSet/Services/Class/Display/0000 but some Win98 SE builds expect 0001 due to prior display driver entries. The LLM detects the blank screen after reboot, identifies the Glide path mismatch via regedit screenshot, and corrects the path.
Failure modes -- when the LLM misreads a Driver Verifier BSOD
The highest failure rate occurs on BSOD screens at 640x480 16-color VGA fallback. Win98's blue screen font is 8x14 bitmap at that resolution -- the vision model sometimes misreads error codes.
Known misread rates per error type:
- ILLEGAL_INSTRUCTION (C-level): 3% OCR error rate
- PAGE_FAULT_IN_NONPAGED_AREA: 1% error rate (common BSOD, well-represented in training data)
- EXCEPTION_ACCESS_VIOLATION at arbitrary addresses: 8% error rate (hex address OCR)
Mitigation: The loop captures three consecutive frames at 500ms intervals and compares OCR output across all three. Inconsistent reads trigger a Claude API escalation. Per the retro-agent project logs, this reduces the BSOD misparse rate to under 1%.
Benchmark table: install success rate per driver class
| Driver class | Attempts | Success rate | Avg time | Failure mode |
|---|---|---|---|---|
| Voodoo3 3000 PCI (3dfx) | 147 | 94% | 8.2 min | Glide INF registry path (6%) |
| Sound Blaster Audigy FX | 89 | 97% | 6.4 min | MSNP32.DLL missing (3%) |
| Voodoo5 5500 AGP (3dfx) | 62 | 91% | 10.1 min | AGP aperture dialog ambiguity |
| nVidia TNT2 M64 | 44 | 98% | 4.1 min | Near-perfect, minimal dialogs |
| Creative Sound Blaster Live! | 38 | 92% | 7.8 min | Registry cleanup needed |
| Realtek 8139 network | 31 | 99% | 2.3 min | Simplest install path |
Data from retro-agent fleet logs, January-May 2026. All installs on Win98 SE Second Edition.
Claude vs local Qwen3.6 35B for retro-driver work: quality vs cost
| Dimension | Claude 4.x API | Qwen3.6 35B (local, llama.cpp) |
|---|---|---|
| Vision accuracy (800x600 screenshots) | 99.2% | 96.8% |
| Novel BSOD error parsing | Excellent | Moderate (struggles with hex addresses) |
| Dialog text OCR (bitmap fonts) | 99.5% | 97.1% |
| Speed per decision | 2.1s avg | 0.8s avg (80 tok/sec, RTX 3060) |
| Cost per install session | ~$0.40 | ~$0 (GPU electricity only) |
| Recovery from ambiguous state | Strong (world model) | Weaker (confabulates sometimes) |
Hybrid strategy (current fleet default): Run Qwen3.6 35B for all decisions. If response confidence < 0.7 or contains uncertainty phrasing, escalate to Claude API. In practice, ~10% of decisions escalate to Claude. At $0.40/session if all Claude, $0.04/session hybrid.
Reproducing on your own retro rig
Requirements:
- Raspberry Pi 4 8GB or Pi 5 (any RAM tier; 2GB minimum)
- USB VGA capture card (must be UVC class)
- USB HID emulator (Digispark with ArduinoUSB library, or any ATmega32U4 board)
- Python 3.11+, anthropic SDK, ffmpeg, PIL
Clone the project at github.com/voidsstr/retro-agent and run:
For a purely local setup: set provider: ollama and model: qwen3.6:35b-a3b-q4_K_M in config.yaml. The Q4_K_M quantization fits in 12GB VRAM.
Common pitfalls
- UVC capture card that doesn't deliver 640x480@60Hz cleanly: Some cheap capture cards drop frames or deliver interlaced output. The LLM misreads interlaced BSOD screens. Filter for 'capture 800x600 60Hz non-interlaced' in the product spec.
- JPEG compression artifacts at 9pt bitmap fonts: Use quality 90+ for screenshots. Below quality 75, font rendering artifacts cause OCR errors.
- Not logging escalations: Every Claude escalation contains a rare error state your local model can't handle. Log for fine-tuning dataset creation.
- Running the LLM on the Pi 5: The Pi 5 can't run a 35B model. Separate machines: Pi 5 = capture/HID controller, RTX 3060 = model host via LAN Ollama API.
- Trying this on WinXP without adjusting for different dialog fonts: WinXP uses ClearType anti-aliased fonts at higher resolution. OCR accuracy on XP dialogs is actually better than Win98 -- but the capture resolution needs to be bumped to 1024x768.
When NOT to use AI for retro driver installs
- If the driver ships with silent-install support: Some newer retro-community driver packages (e.g., the KGPEX unified Win98 GPU driver) include
/Ssilent flags. Run those directly; no vision loop needed. - If you're doing a one-time build: The setup cost (Pi 5, VGA capture, HID emulator, Ollama server) takes 4-6 hours. For a single build, do it manually. The fleet approach pays off at 5+ machines or repeated re-installs.
FAQ
Why use a vision LLM instead of just scripting the install? Because retro installers don't expose silent-install flags. Per Microsoft's pre-NT6 InstallShield documentation, Win98-era setup wrappers used proprietary script formats with no standardized headless mode. A vision-LLM treats the screenshot as the API.
What's the latency on Claude vision making click decisions? Roughly 2-4 seconds per screenshot end-to-end. Per Anthropic's vision documentation, vision input adds ~800ms to baseline TTFT. Total loop: capture (200ms) + encode (50ms) + API RTT (300ms) + inference (1.5-2.5s) + click emit (50ms).
Can a local Qwen3.6 35B replace Claude? For 70% of cases, yes. The 35B A3B model on an RTX 3060 12GB handles routine dialogs at 80 tok/sec. It struggles with novel BSOD error states where Claude's broader world model wins. The hybrid (Qwen default, Claude escalation) costs ~$0.04/install.
Does this work on Voodoo3 specifically? Yes. Per the project's install logs, the Voodoo3 3000 PCI on Win98 SE succeeds at 94%, with the 6% failure mode (Glide INF registry path mismatch) now documented and patchable. See github.com/voidsstr/retro-agent for the full issue log.
Why Raspberry Pi 5 as the controller? Cost (~$120/node including capture and HID), isolation (no shared OS state with the retro target), and VGA capture fidelity. Four-node fleet under $500.
Citations and sources
- retro-agent project -- github.com/voidsstr/retro-agent
- Anthropic -- Claude Vision Documentation
- VOGONS -- Retro Hardware and Drivers Forum
