Amount of BG tiles used in 8-bit and 16-bit video games

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psycopathicteen
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Amount of BG tiles used in 8-bit and 16-bit video games

Post by psycopathicteen » Wed Mar 31, 2021 5:59 pm

Has anybody ever looked into how BG pattern tables were mapped in various 8-bit and 16-bit video games, how many tiles typically were used per level, and how many individual tile sets were used per game?

I'm guessing the majority of NES games had either exactly 256 tiles per level or close to 256 tiles per level, where as most SNES or Genesis games typically used 1024 tiles per level but were more loose with the number of tiles since 256 tiles are easier to fill up than 1024.

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never-obsolete
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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by never-obsolete » Wed Mar 31, 2021 6:27 pm

For the NES:

If a game has chr-rom and dedicates a 1K slot to a 4-step animation, would you count that as 64 or 256 tiles?

Some games store a font in each 4K/8K bank.

Others store non-graphic data in chr-rom.

Contra uses chr-ram and streams in different tiles during the level, usually at the boss.

Some games pack different tile sets into one chr-rom bank.

In other words, background tile budgets vary wildly.
. That's just like, your opinion, man .

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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by tepples » Wed Mar 31, 2021 6:46 pm

Play through the Mall level in Haunted: Halloween '85 (there's a demo in Action 53 Volume 3) and see how many tiles get streamed into CHR RAM.

psycopathicteen
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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by psycopathicteen » Thu Apr 01, 2021 10:57 am

The main reason I'm bringing this up is because I am making a haunted house level (level 3) that is partially outside which reuses ground tiles from level 1 which is a city level. I don't know if I should cram the haunted house tile set in with the city tile set or use a "split bank" approach where I have, say, up to 512 tiles shared in both level 1 and level 3, and have 512 tiles unique to both levels.

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rainwarrior
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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by rainwarrior » Thu Apr 01, 2021 3:33 pm

psycopathicteen wrote:
Thu Apr 01, 2021 10:57 am
I don't know if I should cram the haunted house tile set in with the city tile set or use a "split bank" approach where I have, say, up to 512 tiles shared in both level 1 and level 3, and have 512 tiles unique to both levels.
From the numbers I'm assuming you're talking about SNES, but I'm not sure where the bank concept comes from when you've got fully writable VRAM? Why would it have to be 512 + 512, and not just as many shared tiles as you have + as many unique tiles as you have? What stops the number from being arbitrary?

psycopathicteen
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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by psycopathicteen » Thu Apr 01, 2021 4:33 pm

It's a lot easier to organize stuff in powers of 2, but yeah I can do arbitrary numbers.

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Gilbert
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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by Gilbert » Thu Apr 01, 2021 8:16 pm

While you can do whatever you want with a VRAM system it would be much easier to manage if you introduce some logical structure to it.

For example the offical tile editor of the PC Engine (DF) arranged the 64kb VRAM into 8 8-kb banks (0-6 in item 2 in the screenshot, 1 bank was used as the work bank so there was no #7). It's of course not required to apply the same banking mechanism when you use them in a game though (still, since the PCE's memory map is arranged into 8 kb banks it would be easier if you store uncompressed tile data in 8kb chunks and transfer one to VRAM one bani at a time).
Last edited by Gilbert on Fri Apr 02, 2021 7:15 am, edited 1 time in total.

psycopathicteen
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Re: Amount of BG tiles used in 8-bit and 16-bit video games

Post by psycopathicteen » Fri Apr 02, 2021 7:00 am

I believe SMW has the VRAM set up in "banks". I think there is one bank for common items such as blocks and coins, another bank for ground tiles and another bank for the far background.

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