Looks like Sandra is correct, you can easily enter the monitor program by booting from the ESALOADR floppy. Just tried it on my E4402B.
When the SA completes booting from the floppy, press 'j' at the serial console then CTRL+C and you're in the monitor program.
***** Mosquito Bootrom *****
Copyright 1988-1997,
Hewlett-Packard Company, all rights reserved.
@(#)HEWLETT-PACKARD, E4401 Bootrom, 3.10
@(#)LDS Rev: 3.02 - Module Incremental (Feb 18 1999)
@(#)Linked: Feb 18 1999 11:46:22
Bootrom Checksum ...
Bootrom DRAM: Testing 69632 bytes at 0x04000000
Non Destructive SRAM Test ...
Main Firmware DRAM: Testing 33484800 bytes at 0x04011000
Main FW Checksum ...
Self-tests complete.SRAM selftest results:
Start = 0xa000000
End = 0xa007fa3
Errors = 0x0
DRAM selftest results:
Start = 0x4011000
End = 0x6000000
Errors = 0x0
hpibPort = 0x8005000
hpibPort = 0x8005000, bus Address = 19
Cache Enabled
16MBytes of FLASH
Download to Flash Selected
Downloading from floppy
>>> mainMain()
text segment: 0x4011000 thru 0x40c0c80 ( afc80 bytes)
data segment: 0x4400000 thru 0x4405ec8 ( 5ec8 bytes)
bss segment: 0x4405ec8 thru 0x4424710 ( 1e848 bytes)
ROM size: 0x000b5b48 ( b5b48 bytes of 4194304 max.)
memory pool (all): 0x04424710 thru 0x05ffffff (29210864 bytes)
Calling start_psos() ...
>>>> debug() process starting
Unknown debug char: '' (0x03). Press '?' for help.
Unknown debug char: '' (0x03). Press '?' for help.
Unknown debug char: 'c' (0x63). Press '?' for help.
Unknown debug char: '' (0x03). Press '?' for help.
Unknown debug char: 'c' (0x63). Press '?' for help.
Unknown debug char: '' (0x03). Press '?' for help.
----- System/pSOS Debug commands: -----
'?' - this help message.
'j' - drop into breakpoint.
'^C' - Abort to monitor.
'^P' - Process status info, and LOTS of it.
'[dD]' - Print DLP debug information.
'[bB]' - Big memory hog report.
'[pP]' - Process ONLY status info.
'[eE]' - Exchange info.
'[tT]' - Time log.
'[hH]' - History log.
'[oO]' - Memory segment ownership.
'[mM]' - Memory segment summary.
'[sS]' - Semaphore ownership, etc.
'[uU]' - maximum process stack Usage.
'[vV]' - memory Validity check.
'[iI]' - Show psosSystemData.
'[1]' - Show NVRAM contents.
'[wW] <process name>' - Show process stack trace.
⸤�Ӱ����Unknown debug char: '' (0x03). Press '?' for help.
Unexpected exception at VBR offset 0x80
Trap #0
format = 0, frame is at 0x4423a50
PC = 0x40b8648
SR = 0x2704
Registers = 0x0a007fa4 thru 0x0a007fef
ROM Monitor
Enter ? for help.
->
I will attempt a memory dump later today. I have a few options installed (B72, 1DN, B7B, A4H, BAA, AYX, B7D, B7E), so hopefully this will be useful.