ioscan -k -is the typical place to start, this provides list of all hardware
dmesg -is the easiest way to get physical memory

SAM is also a great way to get the overview.

Some typical programatic specifics are below.
PROC_SPEED=`echo itick_per_usec/D | adb -k /stand/vmunix /dev/kmem |awk -F: 'NR>1 {print $2}'`
NU_PROC=`echo "runningprocs/D" | adb -k /stand/vmunix /dev/kmem |awk -F: 'NR>1 {print $2}'`
MODEL=`model|awk -F/ '{print $3}'`
MEM=`echo "phys_mem_pages/D"| adb -k /stand/vmunix /dev/kmem |awk -F: 'NR>1 {print$2}'`