Intermec EasyCoder 601 XP Service Manual page 95

Chapter 15 CPU Board
15.2 Circuits and
Straps, cont'd.
CAUTION!
The Electronic Key Circuit (P34) contains an
integrated lithium battery.
Replace only with original
Electronic Key Circuits from Intermec.
Dispose of used Electronic Key Circuits
according to local regulations for lithium
batteries.
94
DRAM Memory (P23–P24)
The DRAM memory (Dynamic Random Access Memory) is the
printer's temporary memory (device "tmp:"). It will lose its content
when the power is turned off or at a power failure. Thus, it should
only be used for data that can easily be recreated or that is only
relevant for one power-on cycle. It is much faster than the flash
memory. Therefore, at start up the kernel is copied from the Flash
memory to the DRAM, where the various Intermec Fingerprint
instructions are executed.
The DRAM is also used for the font cache and various buffers. The
remainder is used for the two print image buffers where the bitmap
patterns are stored prior to printing. One buffer is used for the label
that is being printed, while the other receives the bitmap for next
label as the Intermec Fingerprint instructions are processed. By
switching between the buffers, batch printing without stopping
between labels can be achieved.
There are two sockets for DRAM SIMMs on the CPU board. One
4 Mbyte DRAM SIMM must always be installed in socket P23
(DRAM0). This configuration normally gives a maximum label
length of approximately 300 mm (11.8") regardless of print width,
but depending on how much of the DRAM memory is occupied by
other buffers and files.
The size of the buffers depends on two factors:
• Number of physical dots on the printhead (regardless of "Media;
Width" and "Media; X-start" setup)
• Present "Media; Length" setup value in dots
Calculate the buffer size according to this formula:
(No of dots / 8 + 4) x (Media length in dots) = Buffer size in bytes
(Buffer size in bytes) / 1024 = Buffer size in kbytes
Buffer size in kbytes x 2 = Memory requirement in kbytes
Example:
The number of dots on the printhead is 1984
The Media; Length is set to 1800 dots (150 mm)
[[(1984 / 8) + 4) x (1800)] / 1024] x 2 =886 kbyte total
If a longer print length or more storage space is required, the
memory can be expanded with a second DRAM SIMM with a
technical limit of 32 Mbyte in socket DRAM1-2, which gives a
max. total DRAM size of 36 Mbyte. However, regardless of
memory size there is an absolute print length limit of 32,767 dots
(2,730 mm/107.5"). Refer to the spare parts price list for up-to-date
information on approved DRAM SIMMs.
Electronic Key Circuit (P34)
The Dallas touch memory key in P34 contains the real-time clock
(RTC) oscillator and a no longer used system key. The circuit has
a built-in battery backup with a life of at least 10 years. When the
printer is on, the circuit is power supplied via the CPU board and will
not consume any power from the battery.
Intermec EasyCoder 601 XP – Service Manual Ed. 3