IdeaWell

Project ideas from Hacker News discussions.

Ask HN: Who's still keeping a DOS machine up because the business depends on it?

Hacker News Discussion

📝 Discussion Summary (Click to expand)

Theme 1 – Legacy systems stay in service because replacement is costly, risky, or blocked by certification
Many commenters note that old DOS/Windows machines keep running simply because “it ain’t broke” and the expense or regulatory burden of upgrading outweighs any benefit.
- sgerenser: “If it ain’t broke… they already have a strategy in place (no matter how flawed) and would likely retire before throwing money at something they consider a non problem.”
- Froedlich: “The cost of upgrading to modern software and hardware is substantial, plus the learning curve for something I only do rarely nowadays.”
- cromka: “If it's not broken, don't fix it. Same reason why MTA in NYC still operates subway using 100 y/o signaling hardware on most of the lines.”

Theme 2 – Emulation/virtualization lets old software run on modern hardware
A recurring suggestion is to use DOS emulators, VMs, or ISA‑over‑USB adapters to keep legacy applications alive without maintaining the original hardware.
- sgerenser: “Does the idea make use of https://86box.net? … promising for anything that requires low level/cycle accurate emulation.”
- andix: “You can still get ISA slots on systems as new as Broadwell with an adapter.”
- Froedlich: “I have a client with some business software that runs on DOS … A single Linux server gives serves a dozen VNC sessions with the software running in DOSEMU.”

Theme 3 – Keeping these systems alive faces practical obstacles: money, expertise, spare parts, and audit/compliance issues
Commenters highlight the difficulties of sustaining old gear: dwindling parts, knowledge loss, security audits, and looming problems like the year 2038 bug.
- mlaux: “Customization for every customer and AI not being much of a help are pluses for me… lack of money not so much.”
- andix: “Keeping old hardware running is very fragile. Most spare parts are decades old now too, and nobody knows if they still work properly.”
- ptek: “If it's still running I wonder what they are going to do about the year 2038.”
- jabl: “The auditor probably doesn't know nor care. 'Every windows machine runs antivirus' is a checkbox item, zero thought involved.”

🚀 Project Ideas

Generating project ideas…

DBF2SQLite Hook Runtime for DOS

Summary

  • A DOS‑compatible runtime that intercepts DOS file‑system interrupts (INT 21h) and I/O port accesses to automatically translate legacy dBase/Clipper .DBF files into a live SQLite database while the original application runs unchanged.
  • Core value: enables immediate migration of mission‑critical DOS business apps to a modern, queryable database without rewriting code or sacrificing real‑time operation.

Details

Key Value
Target Audience Small‑to‑mid‑size labs, manufacturers, and service bureaus still running DOS‑based dBase/Clipper applications (e.g., wool testing, antenna control, legacy accounting).
Core Feature Transparent hook layer that logs every DOS file/create/open/read/write interrupt and maps .DBF structures to SQLite tables, plus optional I/O port forwarding to USB/serial adapters.
Tech Stack C/C++ for the DOS TSR (TSR‑style hook), FreeDOS kernel callbacks, SQLite3 embedded library, optional libusb for USB device forwarding.
Difficulty Medium
Monetization Revenue‑ready: per‑seat annual license ($150) with optional support contract.

Notes

  • HN commenters explicitly asked for a “DOS emulator with a really thorough log of every DOS interrupt called and I/O port interacted with” that could “insert rows into a sqlite table when the DOS app updates a .DBF file” (mlaux). This product satisfies that request.
  • Provides a low‑risk migration path for regulated environments where the DOS binary must remain unchanged but data needs to be modernized for reporting, backup, or integration with contemporary systems.

ISA‑over‑USB/PCIe Legacy Card Adapter

Summary

  • A plug‑and‑play hardware bridge (FPGA‑based) that presents a real ISA bus over USB 3.0 or PCIe, allowing vintage ISA data‑acquisition, GPIB, or motion‑control cards to operate in modern PCs without DMA timing loss.
  • Core value: eliminates the need to hunt for obsolete motherboards with ISA slots while preserving exact register‑level behavior required by legacy drivers.

Details

Key Value
Target Audience Engineering labs, manufacturing test benches, and research facilities using ISA‑based instruments (e.g., optical comparators, CNC controllers, radio telescope front‑ends).
Core Feature FPGA implements an ISA bus master/slave with cycle‑accurate timing, USB 3.0/PCIe host interface, and a Windows/Linux driver that exposes the ISA card as a standard Plug‑and‑Play device.
Tech Stack FPGA (Intel Cyclone 10 or Xilinx Artix‑7), USB 3.0 controller IP, Linux kernel driver (usbnet‑style) + Windows INF, C host library for applications.
Difficulty High
Monetization Revenue‑ready: $450 per adapter unit, volume discounts for OEMs.

Notes

  • Multiple commenters noted the difficulty of finding ISA motherboards and the latency concerns of USB‑based ISA emulation (labcomputer, andix). A dedicated FPGA bridge solves both the scarcity and timing issues.
  • Enables continuation of expensive, specialized hardware (e.g., GPIB test rigs, custom imaging ISA cards) while moving the host PC to a maintainable, secure platform.

Certified Legacy OS Virtualization Platform (CLOVP)

Summary

  • A hardened, auditable virtualization stack that can run legacy operating systems (AmigaOS, Windows NT 4.0, MS‑DOS, OS/2) on modern x86‑64 hardware while providing passthrough of proprietary ISA/PCI cards and generating compliance artifacts for regulated industries (nuclear, aerospace, medical).
  • Core value: lets organizations retain certified, “known‑good” software stacks on sustainable hardware, reducing obsolescence risk without requalifying the entire application.

Details

Key Value
Target Audience Operators of critical infrastructure (nuclear plants, utilities, aerospace test labs) and regulated manufacturers that must keep legacy OS/hardware combos running for safety or legal reasons.
Core Feature Type‑1 hypervisor with VT‑d/AMD‑Vi I/O passthrough, custom device models for ISA/PCI legacy buses, immutable VM images, and automated audit report generation (SBOM, change‑log, hardware‑fingerprint).
Tech Stack Linux KVM/QEMU base, custom PCI/ISA backend modules, Rust‑based management UI, OpenSCAP for compliance scanning, C‑based shim for direct hardware access.
Difficulty High
Monetization Revenue‑ready: tiered subscription ($2 k/yr for basic, $10 k/yr for premium with on‑site support and certification assistance).

Notes

  • The nuclear power plant anecdote highlights the need to run AmigaOS on NT 4.0 with direct hardware access while staying audit‑friendly (freeli). CLOVP provides a vetted, documentable alternative to scavenging eBay parts.
  • Commenters discussed the difficulty of getting IT auditors to accept antiquated Windows NT 4.0 machines; a certified virtualization layer with compliance reporting directly addresses that pain point (jabl, gerdesj).

Read Later