Overview

Refer to SegaRetro and System16 (Pre, 16A, 16B) for a general overview of the Sega System 16 and a list of games.

System Pictures

Hardware Revisions

The System 16 has two major hardware variants, known as the System 16A and System 16B. Within the 16A variant there is a major 2.0 board revision, which while looking physically very different is equivalent from a software perspective to the earlier version. There is also a “theoretical” System 16C which added expanded RAM over the System 16B hardware. This hardware never really existed, but it was targeted in a virtual emulation environment for a digital release of “Fantasy Zone II DX” in 2008. This game can be run on System 16B hardware with slight modifications to expand the RAM, however as this is a modification and Sega never produced this hardware themselves, it is not listed here.

Like the System 1, it’s likely that Sega hadn’t officially named this hardware the “System 16” when the original “System 16A” hardware was released. This name doesn’t appear on the game PCB or in any of the manuals and documentation of the time. Unlike the System 1, it’s likely this hardware was intended to be used for more than one specific game, however it was still fairly inflexible. The System 16A was re-engineered with the System 16A 2.0 revision however less than a year after the initial release, which for the first time in Sega arcade hardware introduced a separate ROM board. This hardware is frequently mis-identified as “Pre System 16” on many sites, however the names in the official schematics, years of production, PCB part numbers, and nature of design changes all confirm it was in fact a revision of the 16A hardware.

The switch to a separate ROM board largely insulated details of ROM size and layout from the design of the main board, making it easier for Sega to develop new games without revising the basic hardware, and also making upgrades to newer game releases easier. Sega refined this concept with the System 16B hardware, which introduced an I/O expansion port to allow specialized hardware such as trackballs and analog inputs to be attached for games that required them. Dipswitches were added to the ROM boards during the 16B era, making it easier still to reuse existing hardware and reconfigure devices in the field. Sega carried through these design features to most of their following arcade hardware. The System 16B also formally adopted the System 16 branding, with the name “System 16 BType” being silkscreened onto the board. Sega also used formal names for their various hardware platforms from this time forward.

The following PCBs are known to exist for System 16 hardware:

Documentation

Part      Number	Document	Author	Description	Source
	System 16A 1.1 Schematics (Partial)	Sega	Partial hardware schematics for System 16A 1.1 hardware running on 171-5306/171-5307 main boards. These are the original schematics from Sega. The schematics are supposed to contain 13 sheets, 6 sheets for 171-5306 (No.1), 6 sheets for 171-5307 (No.2), and one sheet containing content for both boards. Unfortunately a single sheet (No.2 7/7) is missing, but that sheet appears to have consisted entirely of the connector pinouts for the 171-5307 (No.2) board, the details of which can be entirely reconstructed from the matching connector pinout sheet for 171-5306 (No.1), which is included in the scanned pages. The schematics are clean, however slightly lower resolution than would be ideal, and some trace details are cut off on the edges of some of the pages.
	System 16A 2.0 Schematics	Sega	Complete hardware schematics for System 16A 2.0 hardware running on 171-5335 main board, with 171-5336 ROM board schematics included. These are the original schematics from Sega.	Original Document
	System 16B Schematics	Sega	Complete hardware schematics for System 16B hardware running on 171-5357 main board, with 171-5358 ROM board schematics included. These are the original schematics from Sega. Alternate Versions System 16B Schematics (Partial) (Annotated) Lower quality schematic scans, missing the last two pages of the main board section. This scan does however include many hand-written annotations in English and Japanese.
420-0005U	Golden Axe Installation and Owner’s Manual	Sega	Golden Axe owners manual and installation instructions, including dipswitch settings. System 16B hardware.
420-0008U	ESWAT Installation and Owner’s Manual	Sega	ESWAT owners manual and installation instructions, including dipswitch settings. System 16B hardware.
420-5288	Quartet Owner’s Manual	Sega	Quartet owners manual and installation instructions, including dipswitch settings. System 16A 2.0 hardware.
999-0055	Aurail Installation and Owner’s Manual	Sega	Aurail owners manual and installation instructions, including dipswitch settings. System 16B hardware.
4201-0001	Alien Syndrome Owner’s Manual	Sega	Alien Syndrome owners manual, including dipswitch settings. System 16A 2.0 hardware.
4201-0002	Shinobi Installation and Owner’s Manual	Sega	Shinobi owners manual and installation instructions, including dipswitch settings. System 16A 1.1 or 16B hardware.
4201-0003	Altered Beast Installation and Owner’s Manual	Sega	Altered Beast owners manual and installation instructions, including dipswitch settings. System 16B hardware.
4201-0004	Wrestle War Installation and Owner’s Manual	Sega	Wrestle War owners manual and installation instructions, including dipswitch settings. System 16B hardware.
	Quartet 2 Installation Manual	Sun	Quartet 2 installation instructions, including dipswitch settings. System 16A 2.0 hardware.

High Resolution Photos

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Miscellaneous Photos

Here’s a collection of images of this system that have been posted online from various sources: Hardware Photos