■3.2 Saturn peripheral standard format

●Purpose of Saturn Peripheral Standard Format

The Saturn Peripheral Standard Format is prepared for the following purposes:

1. Be able to control multiplayer even if the data structure, type, and meaning of peripherals are different.

2. Even if upper-word compatible peripherals are released in the future, such as increasing the number of buttons, increasing the number of analog channels, or adding expansion data, you can still use those peripherals to operate multiplayer.
   Also, the ability to control previously released applications.

●Saturn standard format types and data formats

There are currently four types of Saturn standard formats in consideration of the above-mentioned purposes. Each is explained below.

●Future expansion of the standard format

At present, we have the following four formats available, but we plan to add more formats in the future as the need arises.

• saturn digital device
• saturn analog device
• pointing device
• keyboard device

●Notes on using standard formats

In order to comply with the standard format, when the data size is larger than the standard format, excess data must be deleted and used. Also, when the data size is smaller than the standard format, this is achieved by supplementing the missing data with other data. Also, as an example of how to handle this on the peripheral side, there is an analog XY control such as an analog joystick, but if there is no equivalent digital input, you can use the fact that the analog XY data exceeds a certain value to control U, There is a possibility that the peripheral side may adopt a method of turning the D, L, and R bits ON/OFF.

◆Saturn Digital Device

It is a device consisting only of buttons, such as the standard Saturn PAD.
Peripheral types are based on 0H and data size of 2 bytes.
A feature of the format is that the 1st Data has a configuration equivalent to the Mega Drive 3 button. Compatibility can be ensured by assembling the application so that it can be controlled using only 1st Data. Table 3.10 shows the formats of Saturn digital devices.

Table 3.10 Saturn Digital Device Standard Format

	bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
saturn peripheral id	0	0	0	0	Data size
1st Data	Right	Left	Down	Up	Start	A TRG	C TRG	B TRG
2nd Data	R TRG	X TRG	Y TRG	Z TRG	L TRG	extended data
3rd Data	extended data
・	extended data
・	extended data
nth Data	extended data

A TRG,C TRG,B TRG,R TRG,X TRG,Y TRG,Z TRG,L TRG

Right, Left, Down, Up, Start buttons

It becomes 0 when the button is pressed.

◆Saturn analog device

Devices equipped with an A/D converter such as analog joysticks, analog steering wheels, and tablets.
Peripheral types are based on 1H and data size of 5 bytes. (Actually, it changes for each peripheral.)
A feature of the format is that the 1st Data has a configuration equivalent to the Mega Drive 3-button PAD. Compatibility can be ensured by assembling the application so that it can be controlled using only 1st Data. Table 3.11 shows the standard format for Saturn analog devices.

Table 3.11 Saturn Analog Device Standard Format

	bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
saturn peripheral id	0	0	0	1	Data size
1st Data	Right	Left	Down	Up	Start	A TRG	C TRG	B TRG
2nd Data	R TRG	X TRG	Y TRG	Z TRG	L TRG	extended data
3rd Data	AX7	AX6	AX5	AX4	AX3	AX2	AX1	AX0
4th Data	AY7	AY6	AY5	AY4	AY3	AY2	AY1	AY0
5th Data	AZ7	AZ6	AZ5	AZ4	AZ3	AZ2	AZ1	AZ0
6th Data	extended data
・	extended data
・	extended data
nth Data	extended data

A TRG,C TRG,B TRG,R TRG,X TRG,Y TRG,Z TRG,L TRG

Right, Left, Down, Up, Start buttons

It becomes 0 when the button is pressed.

AX7～AX0,AY7～AY0,AZ7～AZ0

The absolute value of the A/D converter output without sign is output.

AX7〜AX0,AY7〜AY0

The top left is (0,0) and the bottom right is (255,255).

AZ7~AZ0

The bottom is 0 and the top is 255.

reference:

Developer's Information/STN-34 "Analog Mission Stick Manual"

Developer's Information/STN-43 "Multi-controller User's Manual Ver1.00"

◆Pointing device

A device that outputs the amount of movement of a rotary encoder such as a mouse, trackball, etc.
The peripheral type is basically 2H and the data size is 3 bytes.
As a feature of the format, the pointing device data table does not have data equivalent to the Mega Drive 3-button PAD, unlike digital devices, analog devices, and keyboard devices. Furthermore, since the movement of X and Y data is output as the amount of movement (△delta) of the rotary encoder, compatibility cannot be ensured unless all three defined bytes are supported. Table 3.12 shows the standard format for Saturn pointing devices.

Table 3.12 Saturn pointing device standard format

	bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
saturn peripheral id	0	0	1	0	Data size
1st Data	Y Over	X Over	Y Sign	X Sign	Start	Middle	Right	Left
2nd Data	XD7	XD6	XD5	XD4	XD3	XD2	XD1	XD0
3rd Data	YD7	YD6	YD5	YD4	YD3	YD2	YD1	YD0
4th Data	extended data
・	extended data
・	extended data
nth Data	extended data

Y Over,X Over

0:X or Y data is valid.

1: Data is overflowing. (Over 255)

Y Sign,X Sign

0:X,Y data are positive values.

1:X,Y data are negative values.

XD7～XD0,YD7～YD0

Absolute value of mouse movement

Start, Middle, Right, Left nuclear buttons

It becomes 1 when the button is pressed.

reference:

Developer's Information/STN-44 "Shuttle Mouse Supplementary Information"

◆Keyboard device

This device is typified by a full keyboard like the one used in personal computers.
The peripheral type is 3H and the data size is 4 bytes.
A feature of the format is that the 1st Data has a configuration equivalent to the Mega Drive 3-button PAD. Compatibility can be ensured by assembling the application so that it can be controlled using only 1st Data. Table 3.13 shows the standard format for Saturn keyboard devices.

Table 3.13 Saturn keyboard device standard format

	bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
saturn peripheral id	0	0	1	1	Data size
1st Data	Right	Left	Down	Up	Start	A TRG	C TRG	B TRG
2nd Data	R TRG	X TRG	Y TRG	Z TRG	L TRG	extended data
3rd Data	0	Caps Lock	Num Lock	Scrool Lock	Make	1	1	Break
4th Data	D7	D6	D5	D4	D3	D2	D1	D0
5th Data	extended data
・	extended data
・	extended data
nth Data	extended data

A TRG,C TRG,B TRG,R TRG,X TRG,Y TRG,Z TRG,L TRG

Right, Left, Down, Up, Start

It becomes 0 when the button is pressed.

The correspondence between each button and the keys on the keyboard is as follows.

button	Compatible key		button	Compatible key
Right	→		C TRG	C
Left	←		B TRG	X
Down	↓		R TRG	E
Up	↑		X TRG	A
Start	Esc		Y TRG	S
A TRG	Z		Z TRG	D
L TRG	Q

Caps Lock

1: Caps Lock is locked (Caps Lock LED is lit)

Num Lock

1: Num Lock is locked (Num Lock LED is lit)

Scroll Lock

1: Scroll Lock is locked (Scroll Lock LED is lit)

Make

Indicates 1 when there is a valid Make code in D7-D0 (key press indicated by D7-D0 code).

Break

Indicates 1 when there is a valid Break code in D7 to D0 (the key press indicated by the D7 to D0 code is released).

D7～D0

Indicates the key number. Used with Make and Break .

Key code correspondence table

	０	１	２	３	４	５	６	７	８	９	Ａ	Ｂ	Ｃ	Ｄ	Ｅ	Ｆ
00H		Ｆ９		Ｆ５	Ｆ３	Ｆ１	Ｆ２	Ｆ12		Ｆ10	Ｆ８	Ｆ６	Ｆ４	Tab	半全
10H		Alt	Shift	ひら	Ctrl	Ｑた	１	Alt	Ctrl		Ｚつ	Ｓと	Ａち	Ｗて	２
20H		Ｃそ	Ｘさ	Ｄし	Ｅい	４	３		Ｆは	スペース	Ｖひ		Ｔか	Ｒす	５
30H		Ｎみ	Ｂこ	Ｈく	Ｇき	Ｙん	６				Ｍも	Ｊま	Ｕな	７	８
40H		＜ね	Ｋの	Ｉに	Ｏら	０	９			＞る	？め	Ｌり	；れ	Ｐせ	−
50H		＿ろ	：け		＠	＾			CapsL	Shift	Enter	［		］む
60H					変換		Back	無変			￥
70H							Esc		Ｆ11						ScrL
80H		Ins	Pause	Ｆ７	Print	Del	←	Home	End	↑	↓	UP	Down	→

Two key positions

• 11H [Alt key] is on the left side of the keyboard.
• 17H [Alt key]: On the right side.
• 12H [Shift key] is on the left side of the keyboard.
• 59H [Shift key]: On the right side.
• 14H [Ctrl key] is on the left side of the keyboard.
• 18H [Ctrl key]: On the right side.

reference:

Developer's Information/STN-45 "Supplementary explanation of Saturn keyboard"