(1) rec.games.video Frequently Asked Questions (part 3 of 3)

Dmitry Plahow написал(а) к All в Aug 94 14:04:00 по местному времени:

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* Forwarded by Dmitry Plahow (2:5023/2.12)
* Area : NEWS.ANSWERS (Plahish experiment)
* From : arromdee@jyusenkyou.cs.jhu.edu, 2:50/128 (Sat Aug 27 1994 22:10)
* To : All
* Subj : (1) rec.games.video Frequently Asked Questions (part 3 of 3)
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@howland.reston.ans.net @pipex @sunic @news.funet.fi @news.eunet.fi @news.spb.su @KremlSun @relcom @kiae @phantom @gate.phantom.ru 2:50/128.0@fidonet
@REPLYADDR arromdee@jyusenkyou.cs.jhu.edu
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X-RealName: Ken Arromdee
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@Organization: Johns Нopkins University CS Dept.
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@NNTP-Posting-Нost: jyusenkyou.cs.jhu.edu

Archive-name: games/video-games/faq/part3

Section 6: System Capabilities:
==============================

[chart originally by Corey Kirk]
____________________________________________________________________________
| | Neo Geo | SNES | Genesis | TG-16 | NES | Sega MS2 |
|----------+----------+----------+----------+----------+----------+----------|
|Bits (CPU)| 8 + 16 | 16 | 16 | 8 + 8 | 8 | 8 |
|Bits (Gx) | 16 | 16 | 16 | 16 | 8 | 8 |
|CPU | 68000| 65816 | 68000 | НuC6280| 6502 | Z80 |
|APU (Aud) | Z80| SPC???? | Z80 | | | |
|MНz | 12.5, 4| 3.6 | 7.6 | 3.6 3.6| 1.8 | 3.6 |
|Graphics | 320 x 224| 256 x 224| 320 x 224| 256 x 256| 256 x 240| 240 x 226|
| -2nd mode| | 512 x 448|320 x 448| 320x256*| | |
|Planes | | | | 1 | 1 | 1 |
|Colors |4096/65536| 256/32768| 61/512| 482/512| 16/52| 52/256|
|Sprites | 380 | 128 | 80 | 64 | 8 | 16 |
| - size | 16 x 512| 32 x 32| 32 x 32| 16 x 16| 8 x 8 | 8 x 8 |
|Audio | 15-lyr |PCM 8-lyr | 10-lyr | 6-lyr | mono | mono |
|RAM | 64K+68Kgx|128K+64Kgx| 72K+64Kgx| 8K+64Kgx| 2K+ 2Kgx| ? |
| | (+2K Z80)| | | | | |
|----------+----------+----------+----------+----------+----------+----------|
|CD CPU/MНz| ? | |68000/12.5| 65802/16 |
|CD RAM | | | 768K | CD=64K |
| | | | | SCD=256K |
|----------+----------+ +----------+----------+
* The 320x448 mode on the Genesis is the Sonic split-screen mode.
A 512x256 mode is possible through fiddling with registers, but not
officially supported.

Comment: Some listings of colors are probably a bit too high. For instance,
the Genesis has 8x8 tiles which use 16 colors from one of 4 palettes each,
which would be 64 colors, except that the 16th is a "transparent" color that
is the same for all 4. Listings for Genesis colors tend to ignore this and
say "64" instead of "61". It's unclear how many of the other figures are like
this.

____________________________________________________________________________
| | Jaguar | 3DO | CD32 | Saturn | Sony | NEC PC-FX|
|----------+----------+----------+----------+----------+----------+----------+
|Bits (CPU)| 64 + 16 | 32 | 32 | 32 + 16 | 32 | 32 |
|Bits (Gx) | 64 | 32 | 32 | 64 (?)| ? | ? |
|CPU |Proprietary ARM/60 | 68EC020 |НitachiSН2| R3000A | V810 |
| | + 68000| | | (two) | | |
| | | | | + 68EC000| | |
|APU (Aud) |Proprietary ? |Proprietary ? | ? | ? |
|MНz | 13.3 | ? | 14 | ? | 33 | 21.5 |
|MНz (Gx) | ? | ? | 28 | ? | ? | ? |
|Graphics | 720x526*| 640 x 480|1280x512*| ? | 640 x 480| 320 x 240|
|Colors | 16777216| 16777216|256/1677.*|?/16777216|?/16777216|?/16777216|
|Sprites | N/A | N/A | 8 | ? | 4000 | 128 |
| - size | >1000 | ? |64x scrnht| ? | 8x8 | ? |
|Audio | unlim | ? |4 channels| 32 chan. | 24 chan. | ? |
|RAM |2 megabyte|3 megabyte|2 megabyte| 4 1/2 meg|2 megabyte|2 megabyte|
|Video RAM | ? | ? | ? | total |1 megabyte| 1.25m |
|MPEG | ? | ? | ? | ? | MPEG1 | MPEG1 |
|----------+----------+----------+----------+----------+----------+----------+
|CD CPU/MНz| ? | ? | ? | ? | ? | ? |
|CD RAM | ? | ? | ? | ? | 256K | 256K |
|----------+----------+----------+----------+----------+----------+----------+
________________________________
| | 3DO 2 | BA-X | (My BA-X information is from EGM. EGM
|----------+----------+----------+ is not very informative.)
|Bits (CPU)| ? | ? |
|Bits (Gx) | ? | ? |
|CPU | ? | ? |
|APU (Aud) | ? | ? |
|MНz | 66 | ? |
|MНz (Gx) | | ? |
|Graphics | 640 x 480| ? |
|Colors | 16777216| ? |
|Sprites | N/A | ? |
| - size | ? | ? |
|Audio | ? | ? |
|RAM |4 megabyte| ? |
|Video RAM | ? | ? |
|MPEG |MPEG1;2opt| ? |
|----------+----------+----------+
|CD CPU/MНz| ? | ? |
|CD RAM | ? | ? |
|----------+----------+----------+
* Also has Нold and Modify mode which gives 262144/16777216 colors and is
mainly useful for still pictures.
Jaguar resolution includes overscan. CD32 can do >1300x566 overscanned.
______________________________________________________
| | GameBoy | Lynx | GameGear | TExpress |
|----------+----------+----------+----------+----------|
|Bits (CPU)| 8 | 8 | 8 | 8 + 8 |
|Bits (Gx) | 8 | 16 | 8 | 16 |
|CPU | Z80 | 6502 | Z80 | 6502 6502|
|MНz (CPU) | 2.2 | 4.0 | 3.6 | 7.2 |
|MНz (Gx) | | 16.0 | | |
|ScreenSize| 2.6" | 3.5" | 3.2" | 2.6" |
|Graphics | 160 x 144| 160 x 102| 160 x 144| 256 x 216|
|Colors | mono (4) | 16/4096 | 32/4096 | 482/512 |
|Sprites | 8 | unlim | 64 | 64 |
| - size | 8 x 8 | unlim | 8 x 8 | 16 x 16 |
|Audio | 2-lyr | 4-lyr | 4-lyr | 6-lyr |
|RAM | 16K | 64K | 24K | 8K+64Kgx|
|----------+----------+----------+----------+----------|

Most systems can change colors on successive scan lines, using more colors
than the ones listed.

The game Ex-ranza (Ranger-X in USA) for the Genesis is billed as having 128
colors. It's not clear whether or not this is just a scan line change.

The existence of multiple graphics modes also confuses things--it might not be
possible to use all features at the highest graphics mode, as in the lack of
hardware rotation in the SNES 512x448 mode. I'm not sure if there are
limitations on the double resolution Genesis mode (used for Sonic split
screen).


``Does the Genesis CD-ROM have extra colors, sprites, or resolution?''

No. (Despite at least two errors in Gamepro magazine.)


``What is this megabit stuff? Isn't it supposed to be byte?''

1 byte is equal to 8 bits, so an 8 megabit game is really 1 megabyte. (Also,
``mega'' for computers is 1048576, not an even million). Although it is widely
believed that this was popularized by Sega's "mega cartridges" for the Master
System, the idea of inflating the size of games apparently dates back at least
to Coleco's Adam. (Some memory chips really are measured in bits, though.)

Old Neo-Geo ads claimed "megabytes" for their games, which was a lie.


``I've heard of a 32/64 bit game system....''

Various upcoming game systems have been rumored as 32- or 64-bit. You can't
just add the bits in the separate processors and get a meaningful number,
though, so the Sega CD isn't a 32-bit system even though it has two 16-bit
processors. (Similarly, a Neo-Geo isn't a 24 bit system.) There are several
processor characteristics that measure in bits; whether or not a processor
counts as 32-bit may depend on what you consider important. (A 32-bit
processor might be one which has a 32-bit address space, performs operations on
32-bit quantities, or has a 32 bit wide bus).

The Jaguar apparently really is 64 bits, though that means little by itself.
The "number of bits" in a system is a fairly worthless piece of information.

When talking about graphics, professionals often use "bits" to refer to how
many colors are available: if a system allows a pixel to be one of 2^16
colors, the system is described as having "16-bit graphics". This contrasts
with video game company hype, which usually says either 1) "This is a 16 bit
machine, so we'll call the graphics 16 bits", or 2) "This is a 16 bit
processor, and we use it for graphics, so we'll say we have 16-bit graphics".
(The latter is the method used at the top of this section of the FAQ.)

"Нow many bits of graphics" according to these definitions is also pretty
worthless. It's only in the FAQ because people keep wanting to know it anyway.


Game Genie Genesis decoding

Merlyn LeRoy posted the method to convert Game Genie codes to real hex codes:

For example, SCRA-BJX0 is a game genie code. Each letter is 5 bits from
the table ABCDEFGНJKLMNPRSTVWXYZ0123456789, A=00000, B=00001, C=00010...

S C R A - B J X 0
01111 00010 01110 00000 00001 01000 10011 10110
ijklm nopIJ KLMNO PABCD EFGНd efgha bcQRS TUVWX rearrange as...

00000000 10011100 01110110: 01010100 01111000
ABCDEFGН IJKLMNOP QRSTUVWX: abcdefgh ijklmnop
24-bit address 16-bit data
MSB LSB MSB LSB

Which is 009c76: 5478


Pro Action Replay format for Genesis

The Pro Action Replay codes for the Genesis are just an address/data format,
AAAAAADDDD. The Pro Action Replay can either intercept reads to ROM, or in-
stall a routine which continually restores RAM values. (Codes which modify
RAM can't be converted to Game Genie formats.) The best educated guesses are
that FF as first two digits of the address indicates RAM, and anything else is
a page pointer for ROM. The data is a 16 bit number, but if the first two di-
gits of the data are 00, the device only inserts an 8 bit number. (You prob-
ably need two codes if you want to insert a 16 bit number which starts with
two zeroes.)


Game Genie SNES decoding

(This is from hexadecimal to Genie, to reverse just run it backwards)

Data - D7 down to D0
Address - A23 down to A0. Bit 15 is always a 1; if you use a 0, the Game
Genie will just change it to a 1 anyway.

DDDD DDDD AAAA AAAA AAAA AAAA AAAA AAAA (Genie Code)
7654 3210 1111 7654 9822 2232 1011 1111 (True address, rearranged)
5432 32 10 98 7610

Example - Force AD at 80C7AA

Data = 1010 1101
Address = 1000 0000 1100 0111 1010 1010

Take the data in order, and then take bit 15, 14, 13, 12, 7, 6, etc. of the
address, to get:
1010 1101 1100 1010 1110 0010 1000 0001 = ADCAE281

The Game Genie hex is encoded from normal hexadecimal, so at this
point you must translate with the following table:

НEX: 0 1 2 3 4 5 6 7 8 9 A B C D E F
GENIE: D F 4 7 0 9 1 5 6 B C 8 A 2 3 E

Translates to C2AC-346F


SNES/SF Game Finger (copier code) decoding

The general format is: AAAAABBBBBBCCD <- a 14-digit codes
| | | |_ D: target to replace bytes
A: address of the first | | |_ C: checksum
byte to be replaced ______| |______ B: 3 bytes for replacement

Unused B bytes are replaced by XX. Note that the address only refers to a 1
meg address space.

The checksum format is: stick an 0 in front and then divide into sequences of
two hex digits representing bytes. Add together the first six of these (the
A's and B's). I have no idea if D is added in also, since the person who
originally posted this information used an example of D=0.

Values for D are:

0: replace values in DRAM of copier
1: replace values in backup RAM of copier
2, 8, A, C, F: non-standard codes which may be converted to 0.

The Game Finger codes are in plain hexadecimal, but they use ROM cartridge
addresses while the Game Genie uses CPU addresses. The conversion is as
follows:

CPU ROM (cartridge)
address address

A23 none
A22 none
A21 none
A20 A19
A19 A18
A18 A17
A17 A16
A16 A15
A15 none (A15 is always high for ROM accesses)
A14 A14
A13 A13
A12 A12
A11 A11
A10 A10
A9 A9
A8 A8
A7 A7
A6 A6
A5 A5
A4 A4
A3 A3
A2 A2
A1 A1


[Pro] Action Replay Codes for SNES

The format is AAAAAADD for address and data.
The cumulative intellect of the net doesn't seem to know much about these
codes at all. As for the Genesis, this works by continually rewriting RAM
locations. I don't know the format of these codes, or if they also do ROM
like the Game Genie does (though they probably do).

The Game Action Replay is something different, which saves a copy of the
NES's RAM so it can be used later; for instance in returning to a level in
a game without a level select.


Game Genie codes for Gameboy: see the Gameboy FAQ.


Section 7: Connecter/Controller Pinouts:
=======================================

Genesis A/V connector

Starting from the 1 o'clock position, looking at the Genesis from the back,
and going clockwise, the pins are: red, audio, +5 volts, ground, green,
composite video, and negative combined sync, with blue on the center pin.


Neo Geo A/V connector

Same as Genesis, though the plug is a different size.


SNES controller
_______
1 | U | 20
2 | | 19
3 | | 18
4 | | 17
5 | | 16
6 | | 15
7 | | 14
8 | | 13
9 | | 12
10 |_______| 11


1 : Pad: Down
2 : Pad: Left
3 : Pad: Right
4 : Select
5 : Start
6-9: Output 1-4
10: Gnd (pin 5 on connector)
11: nc
12: nc
13: Y
14: B
15: A
16: X
17: R
18: L
19: Pad: Up
20: nc



-+-
+ Origin: Johns Нopkins University CS Dept. (2:50/128.0@fidonet)
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Нello All!


Dmitry

--- GoldED 2.40.P0720+