QMS 860, User Manual, Page: 338 / 398

Calculating the Frame Buffer Size
The following formulas should help you determine the minimum
number of kilobytes required in the frame buffer for any printing
situation. Your printer requires additional memory in the frame
buffer to print at rated speed.
paper feed width (inches) x horiz. resolution (dpi)
÷
8 = scanline width (bytes)
paper feed length (inches)x vert. resolution(dpi) = number of scanlines
scanline width (bytes) x number of scanlines = total frame buffer memory (bytes)
Bytes
÷
1024 = KB
For example, if you are printing a 8 1
⁄
2
" x 11" page at 600 x 600 dpi,
with the short edge of the page fed into the printer first, your
equations would look like this:
8.5 x 600
÷
8 = 638 bytes (scanline width)
11 x 600 = 6,600 (number of scanlines)
638 x 6,600 = 4,210,800 bytes or 4,113 kilobytes
(4,210,800
÷
1024 = 4113 KB)
NOTE: If you do an equation for printing at 300 x 300 dpi and
want to change it to 600 x 600 dpi, you can just quadruple
the frame memory size (double the resolution for both the
vertical and horizontal edge of the page).
Special Considerations
The frame buffer memory client is considered the excess memory
client for your printer. You can manipulate this client by taking
memory from other clients since any extra memory that is not
allocated elsewhere is allocated to the frame buffer. For example,
you can add memory to the frame buffer by reducing the amount
of memory dedicated to other memory clients, such as the
Appendix F
F - 1 0 A d d i t i o n a l T e c h n i c a l I n f o r m a t i o n