IBM 1725 SLS - Manual (Page 91)

Memory
2-57 Printer Configuration
Frame Buffer
The Frame Buffer memory client holds rasterized or bitmapped
images of page faces which are ready to be sent to the print engine.
A frame holds the contents of each single page image.
Claculating the Frame Buffer Size
The following formulas should help you determine the minimum num-
ber of kilobytes required in the frame buffer for any printing situation.
Your printer may require additional memory in the frame buffer to print
at a rated speed.
paper feed width (inches) x horizon. resolution (dpi)
÷
8 = scanline
width (bytes)
paper feed length (inches) x vert. resolution(dpi) = number of scan-
lines
scanline width (bytes) x number of scanlines = total frame buffer
memory (bytes)
bytes
÷ 1024 = KB
For example, if you are printing a duplex, 8.5 x 11.0'' page at 600 dpi,
with the short edge of the page fed into the printer first, your equation
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
4,210,800 ÷ 1024 = 4,113 kilobytes
Now, since in this example you are duplexing, you must double the
frame buffer memory to 8,421,600 bytes or 8,225 KB.
If you are uncertain about how to configure your printer’s memory,
use only the Quick Config menu. Memory is then automatically allo-
cated to the memory clients that require it. Any excess memory is
allocated to the Frame Buffer client.