Doom delivers five minutes of terminal violence on an IBM mainframe

Browser demo renders the classic shooter in ASCII, with no login required and considerable squinting encouraged

Can an IBM Z mainframe run Doom? Of course it can. The more interesting question is whether you can play it through a text terminal without ruining your eyesight.

WND Software's browser demo connects to an IBM Z mainframe over SSH using its terminal emulator. Wojciech Graj's DOOM-ASCII supplies the text-based carnage, replacing conventional graphics with colored characters. There's no sound.

It is, however, completely playable (although you might need to recalibrate your vision to work out what is going on, particularly with regard to distant objects). Sessions are limited to five minutes, with room for up to 50 simultaneous users, but we had no trouble getting in. ASCII also presented no issues once the game was in motion. This writer played the original shareware release on an Amstrad ALT386SX portable, so squinting at an indistinct demon felt reassuringly familiar.

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That Doom can be persuaded to run on an IBM Z mainframe is not particularly noteworthy. The code has turned up everywhere from databases to PCB designers. Even the humble Pi Pico was roped into the fun. 

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Keeping the action playable through a text terminal is the more entertaining achievement. A year ago, an IBM consultant persuaded Doom to run on IBM Z and LinuxONE using VNC to bring the pixelated mayhem to life. Using a terminal emulator, while a neat demonstration of the capabilities of WND's software, is perhaps more an example of "because I can" masochism.

It's undeniably an enjoyable way to burn through five minutes. No installation or login required – just a willingness to shoot at punctuation. ®