The previous version of this article said, in part,

LMP files can only be played back with exactly the same version of the DOOM engine (or Source port as the demo was recorded with. In most cases, this is Doom 1.9.

I removed the second sentence and replaced it with

A demo downloaded from the internet at random will usually be vanilla v1.9 or v1.666 format, simply because the height of Doom's popularity occurred at that time, before source ports existed.

This is merely a guess at what the original author meant, of course, but at face value it seems like a reasonable statement.    Ryan W 06:26, 28 December 2007 (UTC)

Merged LMP article content[edit]

One thing I removed when merging earlier was the first paragraph from the LMP article (it seemed like an unwarranted and non-encyclopedic way to start the subject), and the local paragraph about demos desynching when loading the IWAD as a PWAD and whatnot, as that's incorrect. Those demos desynch because a different executable version is used (between v1.9 and v1.9f), and not because of the way the IWAD is loaded. Who is like God? 22:53, 20 March 2008 (UTC)

Maximum LMP size[edit]

IMHO this should be discussed here, but apparently no data is given in any of the places I would have expected it (r.g.c.d., Uwe Girlich's tabulation, etc).  It may depend on version and environment: [1].    Ryan W 21:53, 23 September 2008 (UTC)

It's a rather tricky aspect. Running Doom2 on Windows 98 I've been able to use -maxdemo 4096, but it fails sometimes when adding a PWAD or the like, where something like 3072 seemed to work. Who is like God? 22:03, 23 September 2008 (UTC)


Couple of problems with the newest revision:

  • Embedded tables are best avoided for accessibility and readability. I feel it'd be better to break the explanation of those fields out into separate tables below.
  • Your interpretation of the weapon change bits is incorrect and appears to be based on an understanding of Boom and not vanilla Doom. In vanilla Doom, the weapon change bits of ticcmd_t encode the key number pressed, not the weapon number. Special code in p_user.c figures out what weapon to change to based on the key pressed and the player's current weapon number. This means it is impossible to directly change to the super shotgun via a dedicated key - instead, you can only change to it when pressing 3 if you own it, whether or not you also have the regular shotgun. If you look at g_game.c in function G_BuildTiccmd the loop checking for weapon key presses iterates from 0 to NUMWEAPONS-1, or in other words, from wp_fist to wp_chainsaw - there is no wp_supershotgun key. Only in Boom.

Until these issues are repaired, I cannot review the current revision as stable. --Quasar (talk) 07:22, 7 March 2015 (UTC)

First point was approved by me, woops.  Should I unroll it, or will fixing the second point possibly change the structure?    Ryan W (talk) 21:47, 19 April 2015 (UTC)
I have tagged the section as disputed and cleanup until this is taken care of. I want that wikia link removed as well when it's rewritten. --Quasar (talk) 12:01, 12 June 2015 (CDT)


There is a source section with explicit link and attribution to the wiki that must not be named. Is it really needed? You'd expect all pages would have that, then, given the fork. --Gez (talk) 20:20, 27 March 2018 (CDT)

All pages don't need it because the fork preserved revision histories (showing individual authors).  It's supposed to happen only when text is copypasted by a user who wasn't responsible for all associated Wikia edits, and therefore can't simply agree to republish the content here.  Of course we explain at every opportunity why this is unhealthy, and we have sometimes recreated existing research from scratch to avoid such links.  Each contributor still has this choice, however, and some will always switch their brains off and assume the first Google hit is valid.    Ryan W (living fossil) 21:03, 27 March 2018 (CDT)
This is the offending revision: - if somebody wants to replace the content in that edit entirely, then the attribution can be removed. Note the content also uses bad nested tables which are poor for accessibility and difficult enough for ordinary users to make heads or tails of in the first place. --Quasar (talk) 03:28, 28 March 2018 (CDT)

Bad wiki attribution[edit]

Do we really need to carry this ad-batross round our neck? --Gez (talk) 16:14, 17 July 2018 (CDT)

Heretic desyncs - Firemace to blame?[edit]

I notice that of the Heretic demos, the two that desync are on levels that have firemace spawn spots, while the other does not. Is it known, or believed, that the change in firemace spawning behavior is solely to blame for the desyncs, or are there known or suspected other factors that could also be contributing to them? -- ETTiNGRiNDER (talk) 17:41, 1 January 2020 (CST)