HP 9000 720, 730 and 750

Quick Facts
Introduced	1991
Period	Growth (II)
Series	700 Series
CPU	PA-7000 32-bit 50/66 MHz
Caches	384-512 KB
RAM	272 MB (730) 768 MB (750)
Design	ASP
Drives	2 SCSI (720/730) 4 SCSI (750)
Expansion	1 SGC, 1 EISA (720/730) 2 SGC, 4 EISA (750)
I/O	Ethernet SCSI 2 serial parallel HIL

HP 9000 720, 730 and 750 were the first dedicated 32-bit PA-RISC workstations, released in 1991. Called Snakes, they were based on the first PA-RISC 1.1 processor, the PA-7000 (PCX-S), which was designed to power low cost high performance workstations.

The Snake workstations were designed for graphics and technical computing, so many I/O controllers and interfaces were integrated into the system, such as NCR SCSI, HP graphics and Intel Ethernet networking.

The new look industrial design of 720 and 730 workstations was done by ZibaDesign and Roche-Harkins as a design framework for a new family of workstations. The cases were very solid and used interlocking modules, sliders, for I/O components such as storage, which connected to the main I/O board with a short external cable. 720 and 730 share the same backplane and I/O board which could be upgraded through the exchange of the CPU system board.

HP 9000 720, 730 and 750 were widely used by the US Navy through the TAC-3 (Tactical Advanced Computer) framework for military applications, including electronic intelligence gathering (ELINT).

Later HP 9000/735 workstations share a similar case and system setup as the Snakes: 720 and 730 CPU and I/O boards can be swapped for 735 boards for a system upgrade, and vice versa (735 I/O boards do not work with 720 CPU boards).

HP 9000 720 were introduced in 1991 for $15,890
- 720 CRX Color 2D/3D Workstation for $22,890
- 720 PVRX Color 3D Workstation for $34,390
- Upgrade to 730, CPU board $9,000
HP 9000 730 were introduced in 1991 for $21,890
- 730 CRX Color 2D/3D Workstation for $28,890
- 730 PVRX Color 3D Workstation for $40,390
HP 9000 750 were introduced in 1991 for $43,090
- 750 PVRX Color 3D Workstation for $118,090
- 750 TVRX Color 3D Workstation T4 for $58,090
- 112MB additional RAM for $39,200

Especially the more affordable 720 and 730 workstations were widely used in the Unix world of the 1990s, in academia and industry for technical design and computing. Due to their popularity, many operating systems run on Snakes workstations and were ported to it, including research and development projects such as OSF/1 and a variety of Mach.

Architecture

Processors

System	CPU	Speed	L1 cache
HP 9000 720	PA-7000 PA-RISC 32-bit	50 MHz	384 KB off-chip
HP 9000 730	PA-7000 PA-RISC 32-bit	66 MHz	384 KB off-chip
HP 9000 750	PA-7000 PA-RISC 32-bit	66 MHz	512 KB off-chip

Chipset

HP ASP chipset
HP Viper memory and I/O controller as VLSI chip
Address buffer/controller, 64-pin VLSI CMOS chip
NCR 53C700 8-bit single-ended SCSI-2
Intel 82596DX 10 Mbit Ethernet controller
Intel 82C501AD Ethernet transceiver
Intel 82350 EISA bus adapter chipset (EISA to GSC)
Other I/O (serial, parallel, i8042)
Graphics through separate boards:
- Optional HP GRX SGC DIO-II video adapters
- Optional HP CRX SGC DIO-II video adapters
- Optional HP CRX-24 SGC DIO-II video adapters

System buses

PBus processor/memory bus at full processor clock with 260 MB/s max data rate
VSC main system (TTL) bus at half processor clock with 132 MB/s max data rate
GSC I/O bus
SGC, expansion of the main VSC bus to SGC expansion cards
EISA, expansion I/O bus for standard I/O cards
SCSI-2 narrow single-ended bus

Expansion

Memory

HP proprietary memory modules, based on DRAMs with error detection and correction (EDC), some shared with 735/755
720 8 slots
730 8 slots and 16 MB onboard, 272 MB (8×32+16) maximum
750 12 slots, 768 MB (12×64) maximum

I/O slots

720/730
- One SGC expansion slot for SGC cards (DIO-II formfactor)
- One EISA slot for EISA cards
750
- Two SGC expansion slots SGC cards (DIO-II formfactor)
- Four EISA slots EISA cards

Storage

720/730 Two SCSI 3.5″ Narrow SE 50-pin hard drives
750 Two SCSI half-height 5.25″ Narrow SE 50-pin SCSI drives and two SCSI full-height 5.25″ Narrow SE 50-pin SCSI drives

I/O ports

SCSI-2 50-pin single-ended
Two serial RS232C DB9 (up to 115200 baud)
Parallel DB25
15-pin AUI 10 Mbit & 10Base2 BNC Ethernet
Graphics depend on installed SGC framebuffer
HP-HIL connector for input devices
Jack for beep audio
Ten LEDs on the front for errors and status messages

Operating systems

HP-UX, the original HP Unix shipped with it
- HP-UX 11.00 in 32-bit mode, might work but unsupported
- HP-UX 10.20 32-bit
- HP-UX 10.00 and HP-UX 10.10, pre-Y2K
- HP-UX 9 (9.01, 9.03, 9.05, 9.07), pre-Y2K
- HP-UX 8 (8.01, 8.05, 8.07), pre-Y2K
PA-RISC Linux, main Linux port to PA-RISC
OpenBSD, open-source Unix-like, ported to PA-RISC
NetBSD, open-source Unix-like, ported to PA-RISC
720 OSF MK-PA, OSF/1 Unix port to PA-RISC
HPBSD, original 4.3BSD Unix on PA-RISC (closed)
Mach 4/Lites, research microkernel with 4.4BSD (with issues)
MkLinux, research Linux with Mach microkernel
OSF MK-PA, OSF/1 Unix port to PA-RISC

Pictures

Benchmarks

Based on old SPEC92 and SPEC95 archives
System	CPU	SPEC92 int	SPEC92 fp	SPEC95 int	SPEC95 fp
HP 9000 720	PA-7000 50 MHz	36.4	58.2	1.20	2.00
HP 9000 730	PA-7000 66 MHz	47.8	75.4	1.50	2.30
HP 9000 750	PA-7000 66 MHz	48.1	75.0	1.50	2.30

Compared to SPEC benchmark data, HP 9000 720, 730 and 750 had similar speed to other contemporary Unix workstations and were faster than Intel 486DX2 and level with Pentium at the same clock but significantly faster in floating point.

Based on old SPEC92 and SPEC95 archives
System	CPU	SPEC92 int	SPEC92 fp	SPEC95 int	SPEC95 fp
HP 9000 755/125	PA-7150 125 MHz	136.0	201.0	3.97	4.61
Intel	Intel Pentium 75MHz	89.1	68.5	2.31	2.02
DEC AlphaStation 200	DEC Alpha 21064 100MHz	74.6	95.2	1.48	2.79
SGI IRIS Indigo IP20	MIPS R4000 100MHz	57.6	60.3
Sun SPARCstation 10	Sun SuperSPARC 40MHz	50.2	60.2	1.13	1.38
Digital DECstation 5000	MIPS R4000 50MHz	43.2	42.1
IBM RS/6000 355	IBM POWER 41MHz	40.7	83.3
Siemens PCE-4C	Intel 486DX2 66MHz	35.8	16.1
Motorola 8000	Motorola 88100 33MHz	27.7	18.8
SGI IRIS Indigo IP12	MIPS R3000 33MHz	22.4	24.2
DEC 5000/33	MIPS R3000 33MHz	20.9	23.4
HP 9000 425e	Motorola 68040 25MHz	12.2	9.3
Digital VAX4000	DEC KA46 22MHz	11.1	12.6

Documentation

Manuals

HP Apollo 9000 Model 720/730 owner’s guide, Hewlett Packard (January 1991, A1926-90001) parisc linux
HP Apollo 9000 Model 750 owner’s guide, Hewlett Packard (June 1991, A1961-90000) parisc linux
Installation Guide for HP Apollo 9000 Model 720/730 Workstations and Servers, Hewlett Packard (May 1991, A1926-90000) hpmuseum
Precision Architecture RISC Diagnostics Manual, Volume 1, Hewlett Packard (August 1991, 09740-90041) hpmuseum
HP Apollo 9000 Series 700 Workstations/Servers CE Handbook, Hewlett Packard (June 1991, A1926-90003) hpmuseum

LED messages

LED errors and status messages might be displayed on the HP 9000 720, 730 and 750 front LEDs

Product sheets

HP Apollo Series 700 Model 720 Workstation, two pager, Hewlett Packard (1991, 5091-0974E) hpmuseum
HP Apollo Series 700 Model 720 Workstation, product brief, Hewlett Packard (1991, 5091-0977E) hpmuseum
HP Apollo Series 700 Model 730 Workstation, two pager, Hewlett Packard (February 1991, 5091-0975E) hpmuseum
HP Apollo Series 700 Model 730 Workstation, product brief, Hewlett Packard (1991, 5091-0979E) hpmuseum
Feel the Power of PA-RISC Workstations, product brief, Hewlett Packard (1991, 5091-0986E) hpmuseum
HP Apollo Series 700 Model 750 Workstation, two pager, Hewlett Packard (Januar 1992, 5091-3188E) hpmuseum
HP Apollo Series 700 U.S. Price Guide, Hewlett Packard (1991, no #) hpmuseum
The Best RISC Workstations in the Industry, Hewlett Packard (February 1992, 5091-0983E) hpmuseum

Articles

System design for a low cost PA-RISC desktop workstation, R. Horning et al, COMPCON Spring '91 Digest of Papers, 1991
CMOS PA-RISC processor for a new family of workstations, M. Forsyth et al, COMPCON Spring '91 Digest of Papers, 1991
Hewlett-Packard Journal August 1992 archive.org
- Midrange PA-RISC Workstations with Price/Performance Leadership, page 6 (Andrew J. DeBaets and Kathleen M. Wheeler)
- HP 9000 Series 700 Workstation Firmware (IODC, PDC) page 9 (Deborah A. Savage)
- VLSI Circuits for Low-End and Midrange PA-RISC Computers, page 12 (Craig A. Gleason et al.)
- HP 9000 Series 700 Input/Output Subsystem, page 26 (Daniel Li and Audrey B. Gore)
- Design Verification of the HP 9000 Series 700 PA-RISC Workstations, page 34 (Ali M. Ahi et al.)
- Mechanical Design of the HP 9000 Models 720 and 730 Workstations, page 43 (Arlen L. Roesner and John P. Hoppal)
- Meeting Manufacturing Challenges for PA-RISC Workstations, page 49 (Spencer M. Ure et al.)
HEWLETT-PACKARD UNLEASHES ITS RS/6000 KILLERS, Tech Monitor archive, March 26, 1991
Snake In the Box, Unix World May 1999, Volume VIII, Number 5, page 79 archive.org
High Performance PA-RISC Snakes Motherboard I/O , Hewlett-Packard 1993, bitsavers
HP Apollo Series 700 Performance Brief, Hewlett Packard (October 1992, 5091-5750E) hpmuseum

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