HP 9000/720, 730 & 750

Overview
Internals
External connectors
References
Operating systems
Benchmarks

Quick Facts
CPU	1 PA-7000 50/66MHz
Caches	384-512KB L1
RAM	272MB (730) 768 (750)
Drives	2 SCSI (720/730) 4 SCSI (750)
Expansion	1 SGC, 1 EISA (720/730) 2 SGC, 4 EISA (750)
Bandwidth	CPU 264MB/s (730/750) CPU 200MB/s (720) Sys 132MB/s (730/750) Sys 100MB/s (720)
I/O	10E SCSI 2 serial parallel HIL

Overview

Project name:

These machines were the first PA-RISC workstations, called the Snakes, and were based on the first PA-RISC 1.1 processors. They were built into very solid cases, consisting of interlocking exchangeable modules (sliders). The storage subsystem has its own slider, connected to the main I/O board with a short external cable. The 720 and 730 share the same backplane and I/O board and can be upgraded through the exchange of the CPU board. Later HP 9000/735 workstations share a similar system setup and 720/730 CPU and I/O boards can be swapped together for 735 boards, and vice versa (as 735 I/O boards do not work with 720 CPU boards, both boards have to be exchanged).

Introduced: June 1991
prices between $11,990 and $118,190.

Internals

CPU

720: PA-7000 50MHz with 128/256KB off-chip I/D L1 cache
730: PA-7000 66MHz with 128/256KB off-chip I/D L1 cache
750: PA-7000 66MHz with 256/256KB off-chip I/D L1 cache

Chipset

ASP chipset, featuring:
- NCR 53C700 8-bit single-ended SCSI-2
- Intel 82596DX 10Mb Ethernet controller
- WD 16C552 parallel
- NS 16550A compatible serial
- 512KB EPROM - the Boot ROM
- 8KB EEPROM for storing system configuration status etc.
- Intel 8042 microprocessor controlling:
  - battery backed RTC
  - system & user timers
  - HP-HIL interface
  - frontpanel system status LEDs
Viper memory and I/O controller
Intel 82C501AD Ethernet transceiver
Intel 82350 EISA bus adapter chipset (EISA to GSC)

Buses

PBus processor/memory bus at processor clock (720: 50MHz with 200MB/s, 730/750: 66MHz with 264MB/s)
VSC main system bus at 0.5 of processor clock (720: 25MHz with 100MB/s, 730/750: 33MHz with 132MB/s)
GSC system-level I/O bus
EISA additional I/O expansion bus
SGC expansion of the mainbus to the SGC expansion cards
SCSI-2 narrow single-ended bus

Memory

HP proprietary memory modules (some shared with 735/755)
720: 8 slots
730: 8 slots and 16MB onboard
272MB (8×32+16) maximum
750: 12 slots
768MB (12×64) maximum

Expansion

720/730:
- one SGC (DIO-II formfactor) expansion slot
- one EISA slot
750:
- Two SGC (DIO-II formfactor) expansion slots
- Four EISA slots

Drives

720/730: one tray for two 3.5″ Narrow SE 50-pin SCSI hard drives
750: one tray for two half-height 5.25″ Narrow SE 50-pin SCSI drives and two trays for one full-height 5.25″ Narrow SE 50-pin SCSI drive each

External connectors

50-pin HD SCSI-2 single-ended
Two DB9 male RS232C serial (up to 115200 baud)
DB25 female parallel
15-pin AUI 10Mbit & 10Base2 BNC Ethernet
Graphics depend on installed SGC framebuffer
HP-HIL connector for input devices
Jack for beep audio

References:

Manuals

Model 720/730 owner’s guide (PDF, 1.8MB)
Model 750 owner’s guide (PDF, 2.1MB)

Articles

Midrange PA-RISC Workstations with Price/Performance Leadership (.pdf) pp. 6-11 Andrew J. DeBaets and Kathleen M. Wheeler (August 1992: Hewlett-Packard Journal)

Operating systems

HP-UX: every release from 10.01-10.20 works.
- 10.20: runs ok on them.
- 11.00: also could work, but a) it is unsupported, b) it is slow and c) some HP-UX patches can leave the system in an unrunnable state.
Linux: works.
OpenBSD: works since XXX.
[On a sidenote, the port to the 720 workstation took nine years to complete (since late 1999).]

Benchmarks

Model	SPEC92, int	SPEC92, fp	SPEC95, int	SPEC95, fp
720	36.4	58.2	1.20	2.00
730	47.8	75.4	1.50	2.30
750	48.1	75.0	1.50	2.30

Compare these with other results on the Benchmarks page.

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