Play Doom on a 8841

[Thomas-Solver]

Hello,

I am intrigued by the 'can it run Doom' community and all of the one off devices it has been installed on. 

I recently got an 8841 and was curious about anyone else's experience with trying this sort of thing.

I have no idea if it will work or not, but it seems like a fun project nonetheless. I have seen it installed on other office phones and enjoy coding and tinkering enough that I am giving it a shot.

Any thoughts or ideas are very much appreciated as I continue diving deeper into this.

[vishalbhandari]

The "Can it run Doom?" community is an incredible showcase of creativity and technical tinkering, and attempting to run Doom on a Cisco 8841 phone is an ambitious and fun project! Here's an overview of the considerations, potential approaches, and challenges for running Doom on this type of device.

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Understanding the Cisco 8841 Hardware

The Cisco 8841 is an IP phone with limited processing power, intended for VoIP operations, and it likely runs a proprietary OS (like Linux-based firmware). Key hardware specs include:

• Processor: Likely an ARM-based chip (low-power, embedded use case).
• Display: A small-resolution screen (likely 480x272), suitable for basic visuals.
• Memory: Limited RAM and flash storage.
• Operating System: Likely a Cisco proprietary OS, with possible Linux underpinnings.

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Challenges

1. Limited Resources:

   • The device's hardware isn't designed for gaming, so you'd need to scale Doom down significantly (e.g., low frame rates, reduced resolution).

2. Closed Firmware:

   • Cisco firmware is not open by default, and modifying or replacing it will require hacking or exploiting the device, which might void warranties or violate policies.

3. Input Mechanism:

   • Doom typically requires keyboard or mouse inputs. On an 8841, you’re limited to the numeric keypad, soft keys, and potentially the touchscreen, making gameplay more difficult.

4. Networking vs. Local Play:

   • The phone is designed for VoIP traffic, so any input/output would have to be carefully managed to avoid interference with its core functions.

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Potential Approaches

1. Running Doom Natively:

   • If the device uses a Linux-based OS, you might compile a lightweight Doom source port like Chocolate Doom for ARM architecture.
   • Access the device’s OS using methods such as SSH (if enabled) or serial debug interfaces.

2. Streaming Doom:

   • Use the phone as a thin client to stream Doom from another device.
   • This could be achieved using technologies like VNC or even custom RTP streams displayed on the phone’s screen.

3. Emulation:

   • If you can install a basic emulator (e.g., DOSBox for ARM), you could run the original DOS version of Doom.
   • This would likely require significant configuration and optimization for the phone's limited capabilities.

4. Custom Firmware:

   • Develop or modify firmware to run Doom. This is the most challenging and invasive approach but offers the most flexibility.

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Getting Started

1. Research the Device:

   • Check forums, GitHub, or hacking communities for insights on accessing the 8841’s internals.
   • Look for projects that have explored running custom software on Cisco phones.

2. Set Up Development Environment:

   • Prepare a cross-compilation toolchain for ARM (if that’s the CPU architecture).
   • Download a minimal Doom engine source port, like Chocolate Doom, and start experimenting with scaling it down.

3. Test Input and Display:

   • Investigate how the phone’s touchscreen or keypad can be mapped to control the game.
   • Work out how to render game visuals on the phone’s screen.

4. Experiment with Debugging:

   • If the phone crashes or bricks, be prepared to recover it using firmware restoration tools.

source port: https://github.com/chocolate-doom/chocolate-doom

[Nithin Eluvathingal]

You won't be able to run any games on the 8841.

Before diving deep and risking bricking the device, make sure you have a support contract to fix it. Otherwise, you might need to get a new phone.