HP 9000 735 and 755

Quick Facts
Introduced	1992
Period	Growth (II)
Series	700 Series
CPU	PA-7100 99 MHz PA-7150 125 MHz
Caches	512 KB
RAM	400 MB (735) 768 MB (755)
Design	ASP2
Drives	2 SCSI (735) 4 SCSI (755)
Expansion	1 SGC, 1 EISA, +1 (735) 2 SGC, 4 EISA (755)
I/O	Ethernet or FDDI 2 SCSI 2 serial parallel HIL audio

HP 9000 735 and 755 were powerful technical and graphical PA-RISC workstations from the early 1990s. They use 32-bit HP PA-7100 or PA-7150 RISC processors — the latter reserved for the fast and expensive 735/125 and 755/125 versions with 125 MHz.

HP 735/99 — 735, Thomas Schanz CC BY-SA 4.0

Both 735 and 755 use heavy desk-side cases with separate modules for I/O and CPU. These boards, along with EISA cages and storage subsystem are built into sliders that can be removed separately from the system.

735 and 755 have similar cases and architecture as their HP 9000/730 and 750 predecessors. They support a large set of I/O buses, expansion options and drives in an updated design. 735 were widely used as FDDI node in Convex computing clusters, 735/125 workstations were rather fast Unix computers of the early 1990s and one of the fastest ever running NeXTSTEP.

HP 9000 735 were apparently used by the US Navy as part of the TAC-3 framework contract (Tactical Advanced Computer), possibly as AN/TSQ-142 mission planning system for the EA-6B aircraft and the HP 9000 755 used in ATWCS for cruise missile planning (Tomahawk).

HP 9000 735/99 were introduced in 1992 for $37,395
HP 9000 735/125 were introduced in 1992 for $35,395 (SPU)
HP 9000 755/99 were introduced in 1992 for $58,995
HP 9000 755/125 were introduced in 1992

System architecture

Processors

System	CPU	Speed	L1 cache
HP 9000 735/99	PA-7100 PA-RISC 32-bit	99 MHz	256/256 KB off-chip
HP 9000 755/99	PA-7100 PA-RISC 32-bit	99 MHz	256/256 KB off-chip
HP 9000 735/125	PA-7150 PA-RISC 32-bit	125 MHz	256/256 KB off-chip
HP 9000 755/125	PA-7150 PA-RISC 32-bit	125 MHz	256/256 KB off-chip

Chipset

HP ASP2 chipset
HP Viper memory and I/O controller
HP Cutoff ASIC, interfacing with memory (Viper) and I/O buses, provides address decoding, bus arbitration and interrupts
HP Shortstop ASIC, coordinates data communication between the I/O buses and the mainbus
NCR 53C700 8-bit single-ended SCSI-2
NCR 53C720 16-bit Fast-Wide high-voltage differential (HVD) SCSI-2
Intel 82596DX 10 Mbit Ethernet controller
AMD Formac Plus Am79C830 FDDI controller
Other I/O (serial, parallel, i8042)
Intel 82350 EISA bus adapter chipset (EISA to GSC)
Audio 16-bit CS4215 CODEC
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
- Optional HP CRX-48Z SGC DIO-II video adapters

System buses

PBus processor/memory bus, 66 MHz on 735/99 and 755/99 (264 MB/s)
VSC main system bus
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
SCSI-2 Fast-Wide high-voltage differential (HVD) main storage I/O bus

Memory

HP proprietary memory modules, same as 720, 730 and 750, and the Nova servers
8-32 MB modules
755 supports 64 MB modules
12 sockets
735 16 MB onboard, 400 MB maximum
755 768 MB maximum

Memory has to be installed in pairs, from bank 0 to the outside

.______________.  to backplane	
|              |________________.
| 				|
| | | | | | | ##### | | | | | | |
| | | | | | | #CPU# | | | | | | |
| | | | | | | ##### | | | | | | |
| | | | | | |       | | | | | | |
| | | | | | |       | | | | | | |
| | | | | | |       | | | | | | |
| | | | | | |       | | | | | | |
| | | |	| | |       | | | | | | |
| | | | | | |	    | | | | | | |
| | | | | | |       | | | | | | |
|				|
| 5 4 3 2 1 0       0 1 2 3 4 5 |
|_______________________________|
\				/

Expansion slots

735
- One SGC in DIO-II formfactor
- One EISA slot
- One special daughter card slot for:
  - A2665A - FDDI SAS daughter card with MIC connector
  - A2658A - AUI Ethernet daughter card
  - A2831A - ThinLAN Ethernet daughter card
755
- Two SGC slots in DIO-II formfactor
- Four EISA slots

Storage

735 one tray for either two 3.5″ SCSI 68-pin Fast-Wide HVD or 50-pin narrow SE hard drives.
755 one tray for two half-height 5.25″ SCSI drives and two trays for one full-height 5.25″ SCSI drive each

External ports

SCSI-2 50-pin single-ended external
SCSI-3 68-pin Fast-Wide high-voltage differential HVD external
Two standard RS232C serial
DB25 parallel
735 15-pin AUI or 10Base2 BNC Ethernet or FDDI SAS MIC connector
755 15-pin AUI & 10Base2 BNC Ethernet connectors
RGB BNC, depends on installed framebuffer, if at all
HP-HIL connector for input devices
Five phone jacks (microphone, headphones, line-in, line-out and speaker)
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 (9.05, 9.07), pre-Y2K
NeXTSTEP, Mach-based Unix with beautiful GUI, PA-RISC in version 3.3
PA-RISC Linux, main Linux port to PA-RISC, supported by HP in the 2000s
OpenBSD, open-source Unix-like, ported to PA-RISC
NetBSD, open-source Unix-like, ported to PA-RISC
Research: HPBSD, original 4.3BSD on PA-RISC
Research: Mach 4/Lites, microkernel with 4.4BSD
Research: MkLinux, Linux with Mach microkernel
Research: OSF MK-PA, OSF/1 Unix port to PA-RISC

Pictures

735/99

735/125

Benchmarks

Based on old SPEC92 and SPEC95 archives
System	CPU	SPEC92 int	SPEC92 fp	SPEC95 int	SPEC95 fp
HP 9000 735/99	PA-7100 99 MHz	109.1	167.9	3.22	4.06
HP 9000 755/99	PA-7100 99 MHz	109.1	167.9	3.22	4.06
HP 9000 735/125	PA-7150 125 MHz	136.0	201.0	3.97	4.61
HP 9000 755/125	PA-7150 125 MHz	136.0	201.0	3.97	4.61

HP 9000 735 comparisons — 735 Competitive Comparisons, © HP 1994

Reviewers of new IBM RS/6000 offerings in Computerworld described the raw power of the 1994 IBM POWER2, however when compared against the 1992-vintage 735 analysts noted that the HP 9000 735 still bested the 3BT with a SPECint92 rating of 136, vs. the IBM machine’s rating of 114.

Based on old SPEC92 and SPEC95 archives
System	CPU	SPEC95 int	SPEC95 fp
Intel Alder	Intel Pentium Pro 150MHz	6.08	5.42
DEC Alphastation 250	DEC Alpha 21064A 266MHz	4.18	6.27
IBM RS/6000 3CT	POWER2 67MHz	3.41	10.2
Sun SPARCstation 20	Sun SuperSPARC II 75MHz	3.11	3.10
Siemens PCE-5S	Intel Pentium 100MHz	4.04	2.35
DEC AlphaStation 200	DEC Alpha 21064 100MHz	1.48	2.79
Sun SPARCstation 10	Sun SuperSPARC 40MHz	1.13	1.38

Documentation

Manuals

HP 9000/735 Second Generation PA-RISC Snakes Workstation, Hewlett-Packard (IEEE paper, 1993) bitsavers
HP Apollo 9000 Series 700 Model 735 Workstations Service Handbook, Hewlett Packard (1992, A2095–90602, edition 00893) parisc-linux
HP 9000 Series 700 Model 735 Owner’s Guide, Hewlett Packard (1992, A2095-90608, edition E0394) hpmuseum
HP 9000 Series 700 Model 735 Hardware Installation Guide, Hewlett Packard (1992, A2095-90000, edition E0493) hpmuseum
HP 9000 Series 700 Model 755 Owner’s Guide, Hewlett Packard (1992, A2288-90607, edition E0894) hpmuseum

LED messages

LED errors and status messages might be displayed on the HP 9000 735 and 755 front LEDs

Product sheets

HP Apollo Series 700 Model 755 Workstation, two pager, Hewlett Packard (October 1992, 5091-9336E) hpmuseum
HP Apollo Series 700 Model 755 Workstation, product brief, Hewlett Packard (April 1993, 5091-5839E) hpmuseum
HP 9000 Series 700 Model 735/125 Product Guide, Hewlett Packard (March 1994, 5962-8546E) hpmuseum
HP Apollo Series 700 Model 735 and 735/125, product brief, Hewlett Packard (April 1993, 5091-5838EE) hpmuseum
HP 9000 Series 700 Model 735 and 735/125, product brief, Hewlett Packard (March 1994, 5091-9898E) hpmuseum
HP 9000 Series 700 Model 735CL Computational Cluster, product brief, Hewlett Packard (March 1994, 5962-8466E) hpmuseum

Articles

The Art Of Computer Design, HP Professional, Hewlett-Packard (March 1997) archive.org
IBM beefs up Unix boxes, Computerworld (1994, Volume 18, Issue 22) archive.org

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