Ibm Custom Character Commands For 24-Pin Printers - Oki MICROLINE ML521 Reference Manual

Your arrangement of dots is translated into code that tells the printer the exact locations of each
dot in each column. The example below shows how this works.
128
64
32
16
Byte 1
8
4
2
1
128
64
32
Byte 2
16
8
4
2
1
128
64
32
Byte 3
16
8
4
2
1
The width of the grid in dots depends on the printing mode in use. This example character is 27
dots wide and has 4 blank columns on either side. We'll print it in 10 cpi Letter Quality. Since
the character is being printed in 24-pin mode, three bytes of data are required to specify a
single column. Just like high resolution 24-pin graphics, the first three bytes specify dot
positions for the second column, and so on up to the last column in which dots will appear.
The value of each byte is determined by adding up the values of its bits.
Note: In all print modes, you can NOT place two dots next ot each other horizontally—you
must skip one column.
The commands below are used to download this data to the printer.

IBM Custom Character Commands for 24-Pin Printers

Characters Command (IBM)
Down Line Load
ML590, ML591
Function
Download Custom
Character
Parameters n n
1 2
These parameters specify the number of bytes in the command string. The total number of bytes
is calculated as follows:
Parameters a a a
1 2 3
Parameters a and a specify the starting address of the custom character data, calculated as
1 2
ASCII
ESC = n n # a a a
1 2 1 2
m ad ad id id d d
1 2 1 2 1
d d d [data]
3 4 5
No. of bytes = n
1
Chapter 5: Custom Character Commands
Dec
27 61 n n 35 a a
3 1 2 1
m ad ad id id d
2 1 2 1 2 1
d d d [data]
3 4 5
+ (n x 256)
2
Hex
a 1B 3D n n 23 a
2 3 1 2
d a m ad ad id id
2 3 1 2 1
d d d d [data]
2 3 4 5
47
a
1 2
d
2 1