Booting from the CR-ROM ISO download on 28 April and get the following:

PSB1...
Plan 9 from Bell Labs
ELCR:0E28
Clockinit...alarminit...meminit...spollo...pcimatch...kbdinit...plan9.ini
probe...probing floppy...probing floppy...probing BIOS...probing
BIOS...islba:drive 0X80 extensions version 48.0 cx 0x5
extgetsize:drive 0x80 info flags 0x1
bios0:drive 0x80 160,000,000,000 bytes, type 3
islba:drive 0x81 extensions version 48.0 cx 0x5
extgetsize:drive 0x80 info flags 0x1
bios 1: drive 0x81: 500,107,862,016 bytes, type 3

And all activity seems to stop with cursor blinking.  Keyboard unresponsive
to CTL-R.

System is a dell precision 390; In BIOS, CR-ROM drive is Primary IDE Master.

As both keyboard and mouse are usb devices thought Išd modify plan.ini, but
not sure which of the isošs plan9.inišs to modify:
/sys/lib/dist/pc/plan9.ini?

Some additional info on the hardware:
- CD Rom - Philips DVD+-RW DVD8801 ATA Device
- IDE Controller is an Intel 82801G (ICH7 family) Ultra ATA Storage
Controllers ­ 27D7F, PCI Bus 0,IRQ: 0x0000000E (14)
- IDE Controller is also an Intel 82801GR/GH SATA ACHI Controller, PCI Bus
0, IRQ: 0x00000012 (20)
- USB controller is Intel 82801G (ICH7 Family)
- Screen card is a Nvidia Quadro NVS 285, PCI Bus location 1, IRQ: 16
(another reason to modify plan9.ini)
-  2 SATA HDD, SATA0=160gig, SATA3=500,00gig (as above)
- uses GRUB