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lem1802.txt
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lem1802.txt
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NE_LEM1802 v1.0
\ | ___
|\ \| ___
| \
NYA ELEKTRISKA
innovation information
DCPU-16 Hardware Info:
Name: LEM1802 - Low Energy Monitor
ID: 0x7349f615, version: 0x1802
Manufacturer: 0x1c6c8b36 (NYA_ELEKTRISKA)
Description:
The LEM1802 is a 128x96 pixel color display compatible with the DCPU-16.
The display is made up of 32x12 16 bit cells. Each cell displays one
monochrome 4x8 pixel character out of 128 available. Each cell has its own
foreground and background color out of a palette of 16 colors.
The LEM1802 is fully backwards compatible with LEM1801 (0x7349f615/0x1801),
and adds support for custom palettes and fixes the double buffer color
bleed bug.
Interrupt behavior:
When a HWI is received by the LEM1802, it reads the A register and does one
of the following actions:
0: MEM_MAP_SCREEN
Reads the B register, and maps the video ram to DCPU-16 ram starting
at address B. See below for a description of video ram.
If B is 0, the screen is disconnected.
When the screen goes from 0 to any other value, the the LEM1802 takes
about one second to start up. Other interrupts sent during this time
are still processed.
1: MEM_MAP_FONT
Reads the B register, and maps the font ram to DCPU-16 ram starting
at address B. See below for a description of font ram.
If B is 0, the default font is used instead.
2: MEM_MAP_PALETTE
Reads the B register, and maps the palette ram to DCPU-16 ram starting
at address B. See below for a description of palette ram.
If B is 0, the default palette is used instead.
3: SET_BORDER_COLOR
Reads the B register, and sets the border color to palette index B&0xF
4: MEM_DUMP_FONT
Reads the B register, and writes the default font data to DCPU-16 ram
starting at address B.
Halts the DCPU-16 for 256 cycles
5: MEM_DUMP_PALETTE
Reads the B register, and writes the default palette data to DCPU-16
ram starting at address B.
Halts the DCPU-16 for 16 cycles
Video ram:
The LEM1802 has no internal video ram, but rather relies on being assigned
an area of the DCPU-16 ram. The size of this area is 386 words, and is
made up of 32x12 cells of the following bit format (in LSB-0):
ffffbbbbBccccccc
The lowest 7 bits (ccccccc) select define character to display.
ffff and bbbb select which foreground and background color to use.
If B (bit 7) is set the character color will blink slowly.
Font ram:
The LEM1802 has a default built in font. If the user chooses, they may
supply their own font by mapping a 256 word memory region with two words
per character in the 128 character font.
By setting bits in these words, different characters and graphics can be
achieved. For example, the character F looks like this:
word0 = 1111111100001001
word1 = 0000100100000000
Or, split into octets:
word0 = 11111111 /
00001001
word1 = 00001001 /
00000000
Palette ram:
The LEM1802 has a default built in palette. If the user chooses, they may
supply their own palette by mapping a 16 word memory region with one word
per palette entry in the 16 color palette.
Each color entry has the following bit format (in LSB-0):
0000rrrrggggbbbb
Where r, g, b are the red, green and blue channels. A higher value means a
lighter color.
A message from Ola:
Hello!
It is fun to see that so many people use our products. When I was a small
boy, my dad used to tell me "Ola, take care of those who understand less
than you. Lack of knowledge is dangerous, but too much is worse".
Here at Nya Elektriska have we always tried to improve mankind by showing
them the tools required to improve and reach their true potential.
Together, you will wake up in time.
- Ola Kristian Carlsson