Demonseedling

Hi guys i know Demuls been around forever but just recently discovered it as i decided to obtain Mame first with loads of roms and im hooked on games of yesterday. Feeling brave i remembered a game i used to play in the arcade called Maze of Kings!! Well due to my amazement i found i could download it and emulate it. It actually works to my amazement through Demul. Got the files needed and Hey Presto it actually runs. Im easily pleased so please forgive my excitement here. For my second mission i thought id go for House of the Dead 2 arcade. Got the files tried to run but oh! dear asking for a bios file i think??? Ive got all the obtainable bios packs for Demul by scouring the web. But clearly or maybe im not going to get it to run as im emulating it and the missing bios files needed have been removed to stop cheeky people like me from trying to play the game. Anyway if ive said too much already by violating the emulating code then im very sorry as new to this. I get i cant and wont ever ask for files as i get thats a big NO NO. (very frustrating as its the first thing you want to ask) but maybe someone can maybe help me indirectly or just tell me to give up as its never going to run. To be honest i did download all the files for all the listed light gun arcade (not dreamcast) games but clearly they are missing the elusive bios files i probably need to run. Running demul 58. Hope some one can advise me on my mission . Many thanks