Agilent Technologies HP 8719D Service Manual page 271

Note
The following descriptions of tests 3 and 4 apply to
instruments with firmware revisions 7.xx and above.
3
non-destructive write/read pattern. A destructive version that writes
over stored data at power-on can be enabled by changing the 4th
switch position of the A7 CPU switch as shown in Figure 10-3.
Normal Mode
4
non-destructive write/read test pattern. A destructive version of this
test is run during power-on.
For additional information, see Internal Tests (near the front of this
section) and the "Digital Control Troubleshooting" chapter.
DSP Wr/R.d.
5
DSP (digital signal processor), both on the A7 CPU assembly, to
Service Key Menus and Error Messages
Verifies the A7 CPU SRAM (long-term) memory with a
Destructive SFIAM
Figure 10-3. Switch Positions on the A7 CPU
Verifies the A7 CPU main memory (DRAM) with a
Verifies the ability of the main processor and the
Test Enabled
Rocker Slide