Latest revision as of 00:18, 30 March 2017

Before

The NeoGeo hardware as it is known is an upgrade of Alpha Denshi's Alpha68k design from 1986. Simply put, it seems that Alpha Denshi (ADK) were the hardware guys, while SNK took care of the games (and money for a while).

ADK employee Eiji Fukatsu is believed to have designed Alpha68k-based boards and the NeoGeo. More infos on GDRI.

The main upgrades were:

Increased horizontal resolution (256 to 320 pixels)
Sprite shrink capability
Better soundchip (YM2203 or YM2413 to YM2610
Faster CPU clock (8MHz to 12MHz)
Board size reduction by using custom chips

The Alpha68k mainly used off-the-shelf logic chips which reveals lots of the NeoGeo's GPU design. The only custom chips used were an early version of PRO-CT0 and SNK-CLK, which provided video timing signals. The graphics data formats used on both systems are exactly the same.

After

South-Korean company Andamiro produced the gambling-oriented Midas 2D system around 1999, which uses the same video logic as the NeoGeo but with a higher color resolution. See MAME's midas.cpp.

It is unknown if the design was sold or if it was "inspired from".

@@ Line 1: / Line 1: @@
-The Alpha68k is an arcade board type from 1986 designed by [[Alpha Denshi]] which is believed to be the hardware on which the NeoGeo was built.
+=Before=
-The Alpha68k is interesting in that it mainly uses classic logic chips instead of ASICs, which reveals lots of the NeoGeo's [[GPU]] design.
+The NeoGeo hardware as it is known is an upgrade of Alpha Denshi's Alpha68k design from 1986. Simply put, it seems that Alpha Denshi (ADK) were the hardware guys, while SNK took care of the games (and money for a while).
-It can't do [[sprites|sprite shrinking]] and has inferior sound.
+[[File:Eijisig.jpg|thumb|ADK employee Eiji Fukatsu is believed to have designed Alpha68k-based boards and the NeoGeo. [http://gdri.smspower.org/wiki/index.php/ADK More infos on GDRI].]]
-=Similarities=
+The main upgrades were:
+* Increased horizontal resolution (256 to 320 pixels)
+* [[Sprites|Sprite]] shrink capability
+* Better soundchip (YM2203 or YM2413 to {{Chipname|YM2610}}
+* Faster [[68k|CPU]] [[clock]] (8MHz to 12MHz)
+* Board size reduction by using custom chips
-* 68k/Z80 pair.
+The Alpha68k mainly used off-the-shelf logic chips which reveals lots of the NeoGeo's [[GPU]] design. The only custom chips used were an early version of {{Chipname|PRO-CT0}} and SNK-CLK, which provided video timing signals. The graphics data formats used on both systems are exactly the same.
-* Same resolution.
-* Same dual line buffer system.
+=After=
-* [[Fix layer]].
-* Uses an early [[PRO-CT0]] chip, same sprite graphics format.
+South-Korean company [http://www.andamiro.com/ Andamiro] produced the gambling-oriented Midas 2D system around 1999, which uses the same video logic as the NeoGeo but with a higher color resolution. See MAME's midas.cpp.
-* Line buffers are cleared to all-ones by pull-up resistors, the NeoGeo also does this (see backdrop color in [[palettes]]).
+It is unknown if the design was sold or if it was "inspired from".
 [[Category:Base system]]

Hardware chronology: Difference between revisions

Latest revision as of 00:18, 30 March 2017

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