A104SB Users’ Guide Page 4
5.2 Busy Output Signal
The controller asserts the Busy output when the input buffer is one character away from
being full. The following character will, however, be loaded into the input buffer. This avoids
any data being lost due to the host not responding to the busy signal immediately (such as
with a double-buffered UART in a PC).
5.3 Printing modes and data buffer
Printing modes include graphics, inverted, double height and double width. Graphics mode
is cancelled at the end of every dot line, whereas the combinations of double height and
width remain in force until cancelled by a new command.
The A104SB will print data before the ESCape code and then implement the new mode
selection. The data buffer accommodates 48 bytes, which can extend over many physical
print lines, depending on the mechanism in use and the data format; and new data can be
entering the buffer as previous data are being printed.
5.4 Character Printing
The A104SB prints the characters from left to right. The characters fit into a 6 wide × 10 high
matrix. The standard letter is 5 wide × 7 high, this provides for a one dot space between
each character, a dot line for descenders and a dot line above and below each character
line. The number of characters required to fill a dot line varies according to the printer
mechanism.
Mech. Characters per line Character lines per
second Vertical dot
pitch Horizontal
dot pitch Paper
width
M-150 16 characters per line 1 line/second 0.35mm 0.35mm 44.5mm
M-160 24 characters per line 0.7 lines/second 0.33mm 0.33mm 57.5mm
M-163 32 characters per line 0.5 lines/second 0.33mm 0.25mm 57.5mm
M-164 40 characters per line 0.4 lines/second 0.33mm 0.20mm 57.5mm
M-170 40 characters per line 0.4 lines/second 0.33mm 0.25mm 69.5mm
The ASCII characters 32 to 255 (32 to 127 if using a backwards compatible 7 bit character
set) are in the printable range. Any character below character 32 is ignored unless it is one
of the control codes (section 5.7).
5.5 Graphics Printing
The product is programmed to take advantage of the graphics printing capability of the
mechanisms. Graphics are received as the least significant 6 bits of each byte. In this way
the same number of graphics bytes are required to terminate a line as the number of
characters required to print a complete line. The graphics mode is reset at the end of every
dot line and hence the graphics command, <ESC><02>, must be entered at the start of
every dot line. Graphics patterns are built up as a succession of dot lines across the paper.
The number of bytes required to fill a dot line for each mechanism are the same as the
number of characters required to fill a dot line. Large areas of solid dots are not
recommended as they may cause over heating and shorten the ribbon life. Heavy graphics
printing may also require a higher current power supply.
A typical graphics line for the A104SB would be:
Control code Data (24 bytes for the M-160 printer mechanism)
<ESC><02> <00><00><01><02><03><04><05> etc.
