Sdram - Working System Ram; Summary - Micros Systems Workstation 4 Setup Manual

What is The Workstation 4?
Memory Architecture
• Working from left to right in the illustration, the OS update image will
be present only if the CAL detects that a newer version of Windows CE
has been staged on the system server and places it on the CF Card.
When the OS update image is present on the CF at boot time, the Boot
Loader copies it over the existing OS image on the DOC.
• The CF Card contains the persistent registry. A WS4 driver called the
PRD (Persistent Registry Driver) periodically copies the working
registry from RAM to the CF card. The PRD ensures that any changes
made to the registry by the OS or application are placed on the
non-volatile CF card.
• The POS application and all support files are stored on the CF Card.
The application is installed by the CAL when a workstation is powered
up for the first time and a LAN connection to the system server is
established.
• POS Application software that supports SAR will use a portion of the
CF card to store off-line transaction totals.

SDRAM - Working System RAM

System or 'working' RAM is contained in a single 168-Pin DIMM socket.
Currently, a 128M PC133, 168-Pin, +3.3V, unbuffered SDRAM is populated in
socket DIMM1. The contents are shown in Figure 1-15, below.
• The RAM holds the runtime requirements of Windows CE and the POS
application code as the WS4 operates. RAM contents are preserved when
the workstation is placed in the
removed from the workstation.
• The working copy of the registry is located in system RAM. The contents
of the RAM are lost if AC power is lost, but the Persistent Registry Driver
(PRD) places the working registry on the non-volatile CF card.

Summary

The Disk On Chip provides a permanent means of storing the operating system
and associated device drivers, as well as system utilities such as the CAL,
SAL, and WS4 diagnostics software.
1-16
Figure 1-15: WS4 System RAM Contents
state, but lost if AC power is
SUSPEND
Workstation 4 Setup Guide