LoROM vs HiROM

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koitsu
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Re: LoROM vs HiROM

Post by koitsu » Fri Jan 06, 2017 7:45 pm

nicklausw wrote:Have you ever felt weird seeing this many people (that being most of SNESdev) using a term you created? I'd feel like some sort of celebrity.
I was completely joking -- I didn't create them. I just wanted to say something that would definitively answer Tepples' question without giving him an avenue for weirdness. ;-) At least it got byuu to make a Jojo reference, which really did get me laughing (I haven't enjoyed an anime/manga that much since Jungle wa itsumo Hare nochi Guu).

The LoROM/HiROM terms were already in use by the time I started getting into SNES development back in 1992 (or was it 1993?). I have several different ideas as to where/how they originated, but I'd rather keep those to myself -- the less misinformation spread, the better. (I had never heard of "ExHiROM" until sometime in maybe 2008?). But if I had to go out on a limb publicly, I would say it probably came from the Amiga/SNES/warez crowd who were distributing ROM sets back in the day. Pretty much all the .nfo files had those labels. "Lo" is probably just a convenient/short (fewer characters) way to say "less" and "Hi" meaning "more". I mention the Amiga because that's a system where you've got 9 billion different kinds of RAM (ChipRAM, SlowRAM, FastRAM, MB RAM, AccelRAM), even though I'm pretty sure all of those have no actual relation to the SNES, I just think the "naming convention" syntax/style might have carried over. There weren't 24mbit or 32mbit carts at the time those terms were created -- I know this for a fact because a paper copy of the official docs I have don't even mention mode 25, nor do they have any of the PCB layouts + memory map details that the last-known-version has.

Optiroc
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Re: LoROM vs HiROM

Post by Optiroc » Sat Jan 07, 2017 8:24 am

My memory fails me here... Anyone remember what terminology the Wildcards, Magicoms, Fighters and assorted Doctors used?

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Bregalad
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Re: LoROM vs HiROM

Post by Bregalad » Sat Jan 07, 2017 10:14 am

I was completely joking -- I didn't create them.
So next time you're telling jokes, could you please make it explicit ? Here it really looks like you were serious about inventing those terms, and this would have been credible.

Not that I personally care who invented them, but I just like it to be clear when people aren't serious.

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tokumaru
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Re: LoROM vs HiROM

Post by tokumaru » Sat Jan 07, 2017 11:49 am

koitsu wrote:I have several different ideas as to where/how they originated, but I'd rather keep those to myself -- the less misinformation spread, the better.
Bregalad wrote:Here it really looks like you were serious about inventing those terms, and this would have been credible.
That's is indeed ironic. I believed it, as would anyone not familiar with the SNES scene reading that post. I don't personally care either, considering I still don't really understand what all those terms mean, but still.

psycopathicteen
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Re: LoROM vs HiROM

Post by psycopathicteen » Sat Jan 07, 2017 12:00 pm

I think they should have different names.

For example, half bank ROM vs full bank ROM.

byuu
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Re: LoROM vs HiROM

Post by byuu » Sat Jan 07, 2017 7:53 pm

Bregalad wrote:
I was completely joking -- I didn't create them.
So next time you're telling jokes, could you please make it explicit ? Here it really looks like you were serious about inventing those terms, and this would have been credible.
Yeah, hate to admit it, but I thought you were serious too, hahah.

I do know it's scene related, as Nintendo used mode numbers (20, 21, 25, ...)

I wasn't around until late '97, early '98 when emulation was starting to become part-way usable (if you didn't mind using something one year less developed than this, at least ... sadly no videos on ESNES v0.11b, or Snes9Xw v0.2.0); so I don't really know where the terms came from either.

(Fun anecdote: I basically begged daily for a computer from as young as I can remember. Didn't ever get an actually usable one until late '97, and so I missed out on the golden age of BBSes, the early internet, and the early emulation scene.)
I had never heard of "ExHiROM" until sometime in maybe 2008?
They were using it to refer to Tales of Phantasia around the ZSNES forums in 2004. I suspect they coined it upon emulating said game, which would've been back around '99 or so?

This is bad that I don't even remember, but ... ExLoROM might've been me? I think it was an idea to expand LoROM games to support > 32mbit, and I believe DMM used it in his translation of Dragon Quest 3R? I know FuSoYa added this support to his Lunar Magic tool, and also released new versions of emulators to support it, so they could expand Super Mario World beyond the 32mbit limit.
My memory fails me here... Anyone remember what terminology the Wildcards, Magicoms, Fighters and assorted Doctors used?
I know their file extensions, at least.

mgd => Multi Game Doctor
mgh => Multi Game Hunter
sf2 => Professor SF2 (English/US/UK? version of Game Doctor)
gd3 => Game Doctor 3
gd7 => Game Doctor 7
fig => Pro Fighter
smc => Super Magicom (actually very uncommon device, yet common extension)
swc => Super Wildcard
ufo => Super UFO

Pretty sure all of them had variations on copier header format (but a consistent size), and also had different rules around interleaving games or not. My Super UFO definitely interleaved 'HiROM' games, as it were.

However, later copiers could often boot games from several other copier header formats.

The Super UFO 8.3j didn't have any actual terminology around 'LoROM/HiROM' anywhere in the UI. It was all hidden in the background technical details.
For example, half bank ROM vs full bank ROM.
For people who don't follow the idea of omitting address lines, you could say 64k granularity vs 32K granularity.

Optiroc
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Re: LoROM vs HiROM

Post by Optiroc » Sun Jan 08, 2017 5:18 am

I for one enjoyed koitsu's good clean joke. (:

Anyway, I looked around for some old file_id.diz:s and "HI-ROM" was around at least as early as 1992. "SlowROM" fixes, too.

Exhibit A:

Code: Select all

PDX-BOM2.LZH    464445  09-03-92   ________/\________  /\_______  /\____ ____
                                   \_____  \ \_____  \/  \____  \/  \   |   /
                                     /  |  /| \/  /  /  | \ |/  /    \  _  /
                                  Mb/   __/ _ /   \  \_ _  \/  /      \ |  \
                                   /    |___| \___|\__/_|   \_/\______/_|   \
                                  (_____|---|____)------|____)-PRESENTS-|____)
                                  Super BomberMan 2 (c) HUDSON [SNES/HI-ROM/8]
Exhibit B:

Code: Select all

 BLH-GGFX.LHA      4715  09-02-92  ____________  ________/\_________  ____[MY]:
                                  \      \_   \/       /  \_/___   \/    \   |
                                  |\__|  / \_  \ \____/   /|__  \_  \ \__ _  |
                                  |  \_  \ _/   \|   |   / /  \ _/   \   \|  |
                                  |  ____/_|\  __\__ |  /\_____\|\ \_____/|__|
                                  :___|======\/==|___|\___\=======\/==|___|==:
                                     Astro Go Go by Anthrox!! - SlOwRoM FiX
I couldn't find any reference to "LO-ROM" though, so that might've been coined by the early emulation scene by simply making up an antonym to "HI-ROM".

Pokun
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Re: LoROM vs HiROM

Post by Pokun » Sat Jan 14, 2017 8:36 am

Yeah Koitsu can't be explicit that he is joking if he is trying to fool you can he? Or else it wouldn't work. :)

From my own notes there are five main map modes, following the official naming in the header:
Mode 20 - LoROM
Mode 21 - HiROM
Mode 22 (S-DD1) (says "reserved for future use" in a revision of the official dev docs) - ExLoROM
Mode 23 (SA-1) - Doesn't seem to have a "scene name"?
Mode 25 - ExHiROM

The byte in the header:
001A0BCD (basic value $20)
A = 0 means SlowROM (+ $0), A = 1 means FastROM (+ $10).
B = 1 means ExHiROM (+ $4)
C = 1 means ExLoROM (+ $2)
D = 0 means LoROM (+ $0), D = 1 means HiROM (+ $1), is used with B and C in case of extended ROMs.

Mode 23 fills the requirements of both ExLoROM and HiROM?
This puzzles me as SA-1 games aren't exactly few, it would seem it would have a scene name.

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Re: LoROM vs HiROM

Post by tepples » Sat Jan 14, 2017 9:30 am

The scene name is SA-1. As on the NES, the rule is that a mapper dominated by a big ASIC gets named after that ASIC, while a board with no big ASIC is named in some other memorable way. For NES, said memorable way is the silkscreened name, while for Super NES, it's the fact that $80-$BF precedes $C0-$DF, just expressed in a manner that looks like an NES board name (or like the parts of Amiga memory).

AWJ
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Re: LoROM vs HiROM

Post by AWJ » Sun Jan 15, 2017 5:40 am

As far as ROM mapping is concerned SDD1 and SA1 are extremely similar. The only difference is that with the SA1 both the "LoROM" and "HiROM" regions can be freely bankswitched in 1 megabyte chunks, whereas with the SDD1 only the "HiROM" region can be bankswitched, the "LoROM" region being fixed to the first 2MB of ROM.

"The scene" confusingly uses ExLoROM to refer to two completely different things. One is the SDD1; the other is a mapping apparently invented by the ROM hacking scene (no commercial cartridges ever used it, nor is it attested in any documentation) that's analogous to Mode 20 in the same way Mode 25 is analogous to Mode 21: one 32 MBit ROM mapped in the fast banks in Mode 20 fashion, and another up-to-32 Mbit ROM mapped in the slow banks. A ROM image using this invented mapping would have its Nintendo header and vectors at 0x407Fxx.

Pokun
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Re: LoROM vs HiROM

Post by Pokun » Sun Jan 15, 2017 7:28 am

I see, so if it would have an official name I guess it would be Mode 24.

In that case it's best to use "ExLoROM" only for this Mode 24 and "S-DD1" for Mode 22 to stay consistent.

In other words:
Official Name - Scene Name
Mode 20 - LoROM
Mode 21 - HiROM
Mode 22 - S-DD1
Mode 23 - SA-1
Mode 24 - ExLoROM (unofficial map mode)
Mode 25 - ExHiROM

Much better.


I guess S-DD1 is called ExLoROM only because it's the closest thing to it among the official map modes, although it's not 100% analogous.

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