How many zombies can Dead Rising display at once?

I haven't found a reliable source. Wikipedia and Wikia link to this LiveJournal post supposedly written by Crispin Boyer writing for Electronic Gaming Monthly.

Plowing through fields of zombies--up to 800 on a screen at once

I didn't find anything official on the Capcom website or in the game manual (Xbox 360). The following text can be found on the back of the game box:

Next generation "swarm" technology surrounds you with hundreds of on-screen zombies to hack, drive and run through.

Googling for the maximum number of on-screen zombies seemed to match up with Electronic Gaming Monthly's claim that the limit is 800.

An interview with one of the co-producers for the second game (Dead Rising 2) shows that there appears to be some form of limit in the first game:

Shin Ohara: [laughs] Well, for Dead Rising 2, what we wanted to do is show a lot of zombies, and the current tech that we had didn't allow us to do that.

The same interview details that the second game (Dead Rising 2) has no limit:

We can show about 7,000 zombies if we wanted to, our technology is not limiting us. If the game only shows about 500 zombies or 1,000 zombies, that's not the game's limit.

There are several mentions of the 800 limit, such as in this question:

Numbers of zombies on screen increased from 800 to 6,000

A comparison with the Wii Version also repeats the claim of 800 zombies for the first game:

Due to the Wii not having the same level of graphical capabilities as the Xbox 360, fewer zombies can appear on screen (800 zombies could be on screen in the Xbox 360 version at once, but now have to be limited to 100), but Capcom had attempted to retain as many of the Xbox 360 features as possible.