To map the code points to bytes, add 158 ( 0x98 ) to the row number of the code point to form the high byte, and add 158 column number of the code point to form the low byte.
12.
This is achieved by playing the high byte of a 16-bit sample at maximum volume, and the low byte at minimum volume ( both ranges overlap, so the low byte needs to be shifted right two bits ).
13.
The 16 virtual registers, 32 bytes in total, are located in the zero page of the Apple II's real, physical memory map ( at ), with values stored as low byte followed by high byte.
14.
The Y coordinate can simply be put in the high byte of the address, and the X coordinate in the low byte, forming the address of the pixel without a multiply, shift or lookup being needed like other video modes.
15.
For example, early ( pre-7.0 ) versions of Apple's Mac OS used the high byte of memory-block master pointers to hold flags such as " locked " and " purgeable ".
16.
However, the extra code points exceeded the original Big-5 definition ( Big5 + uses high byte values 81-FE and low byte values 40-7E and 80-FE ), preventing it from being installed on Microsoft Windows.
17.
Abandoning the ISO-2022 model of strict regions for graphics and control characters, but retaining the feature of low bytes being 1-byte characters and pairs of high bytes denoting a character, you could potentially have 128?= 16, 384 positions.
18.
The expansion of the memory space caused an issue for any programs that used the high byte of an address to store data, a programming trick that was successful with those processors that only have a 24-bit address bus ( 68000 and 68010 ).
19.
Typically, the initial value of the counter is set by sending bytes to the Control, then Data I / O Port registers ( the value 36h sent to port 43h, then the low byte to port 40h, and port 40h again for the high byte ).
20.
For example, if you have the GB2312 code point 4566 ( " Y ", which means foreign ), the high byte will be 4566 / 94 + 158 = 206 = 0xCE, and the low byte will come from 4566 % 94 + 158 = 212 = 0xD4.
