SPED-3 Suspended Particle Exciter Display

The SPED-3 Suspended Particle Exciter Display is a three dimensional display that can be used to display holographic images rendered by the DCPU-16. It is a supplement to the LEM1802 and an additional output device.

The Mackapar Suspended Particle Exciter Display, Rev 3 ("the device") is a 3D vector display unit. Straight lines are drawn between consecutive vertices in a constant loop, with customizable colors per vertex. The effect is similar to a free floating 3D model. The area of the projected model is about 1x1x1 meters, and projection occurs 1.5 meters above the device. The emitters are capable to rotate around the Z axis at 50 degrees per second, allowing for easy animation of projected models. Up to 128 lines may be projected, but the more lines are projected, the more severe the flickering gets.

Hardware details

Name	SPED-3
ID	0x42babf3c
Version	0x0003
Manufacturer	0x1eb37e91

Interrupts

A, B, C, X, Y, Z, I, J below refer to the registers on the DCPU

A	Behavior
0	Poll device. Sets B to the current state (see below) and C to the last error since the last device poll.
1	Map region. Sets the memory map offset to X, and the total number of vertices to render to Y. See below for the encoding information.
2	Rotate device. Sets the target rotation for the device to X%360 degrees.

VERTEX ENCODING

Each vertex occupies two words of information in the main DCPU RAM. The data is encoded as (in LSB-0 format):

 First word: YYYYYYYYXXXXXXXX
Second word: 00000ICCZZZZZZZZ

Where XXXXXXXX is the X-coordinate of the vertex, YYYYYYYY is the Y-coordinate, ZZZZZZZZ is the Z-coordinate, CC is color, and I is intensity.

Z is deeper into the screen, if the device is placed face up on the ground, this translates to "up" relative to the user.

Possible color values are 0: black, 1: red, 2: green, 3: blue.

If the intensity bit is set, the color is drawn as more intense.

The black color is meant to barely be visible at all, except for in very dim environments, or if the intensity bit is set.

STATE CODES

A, B, C, X, Y, Z, I, J below refer to the registers on the DCPU

B	Name	Description
0x0000	STATE_NO_DATA	No vertices queued up, device is in stand-by
0x0001	STATE_RUNNING	The device is projecting lines
0x0002	STATE_TURNING	The device is projecting lines and turning

ERROR CODES

A, B, C, X, Y, Z, I, J below refer to the registers on the DCPU

C	Name	Description
0x0000	ERROR_NONE	There's been no error since the last poll.
0xffff	ERROR_BROKEN	There's been some major software or hardware problem, try turning off and turning on the device again.

External Links and References

• Official specification document: http://dcpu.com/3d-vector-display/
• Announcement by Notch: https://twitter.com/notch/status/253771707624615936