RetroTechCollection

IBM PS/2 Model 30


The IBM Personal System/2 Model 30 (machine type 8530) is one of the four original IBM PS/2 systems announced on April 2, 1987 alongside the IBM PS/2 Model 50, IBM PS/2 Model 60 and IBM PS/2 Model 80. The Model 30 was the lowest-end entry of the original four and was designed to directly replace the IBM PC and PC XT. Unlike the higher-end original PS/2 models, the Model 30 retains an ISA expansion bus rather than the new Micro Channel Architecture (MCA), making it electrically compatible with PC/XT and (with the Model 30 286) PC/AT expansion cards.

IBM Personal System/2 Model 30
IBM PS/2 Model 30 (8530-002 / 021)
Specifications
DeveloperIBM Entry Systems Division, Boca Raton
ManufacturerIBM
TypeDesktop personal computer
ReleasedApril 2, 1987 (Model 30 8086); September 13, 1988 (Model 30 286)
Discontinuedc. 1992 (Model 30 286)
CPUIntel 8086 @ 8 MHz, 0 wait states (Model 30); Intel 80286 @ 10 MHz (Model 30 286)
Memory640 KB on-board (Model 30); 512 KB – 4 MB (Model 30 286)
StorageOne or two 3.5" 720 KB diskette drives, or one 720 KB diskette + 20 MB / 30 MB hard disk
DisplayMCGA (Model 30) or VGA (Model 30 286) integrated on planar
SoundPC speaker; 1/4" mono earphone jack
Dimensions406 W × 397 D × 102 H mm
Weight~8 kg (17.5 lb)
OS / FirmwareIBM PC DOS 3.3 and later; IBM OS/2 1.x (Model 30 286)
PredecessorIBM PC XT (5160)
SuccessorIBM PS/1; IBM PS/ValuePoint
Model no.8530

The Model 30 was sold in two CPU generations:

  • Model 30 (8530-002 / 021) — Intel 8086 at 8 MHz with MCGA video and 8-bit ISA expansion, April 1987 onwards.
  • Model 30 286 (8530-E01 / E21 / E31 / E41) — Intel 80286 at 10 MHz with VGA and 16-bit ISA expansion, September 1988 onwards.

Both generations share the same case mouldings, the same proprietary PS/2 single-cable floppy/hard-drive interface, and the same family of PS/2 (Mini-DIN) keyboard and pointing-device ports. The Model 30 was sold concurrently with the Model 25 (an all-in-one entry-level variant introduced August 1987) and was followed in the home and education market by the IBM PS/1 line from 1990.

History

edit

IBM launched the PS/2 family on April 2, 1987 with the Model 30 (8086), Model 50 (80286 MCA), Model 60 (80286 MCA tower) and Model 80 (80386 MCA tower). The Model 30 was positioned at US $2,295 for the entry-level 8530-002 configuration and US $3,495 for the hard-disk equipped 8530-021. By June 1987 IBM's Boca Raton factory was producing approximately 1,000 Model 50s and 800 Model 60s per day, and Model 30 production was at scale alongside; the Model 30 became the dominant entry-level PS/2 in the first two years of the line.

The Model 30 286 (8530-E series) was announced on September 13, 1988 to address the Model 30 8086's poor performance in business applications and to give the Model 30 line VGA video and an AT-class 80286 CPU at 10 MHz with 16-bit ISA expansion. It was sold concurrently with the original Model 30 8086 until c. 1990, then continued in the catalogue until 1992 when the PS/2 line was largely replaced by the IBM PS/1 and PS/ValuePoint families.

Submodels

edit

The principal Model 30 submodels are listed below. The 8530-E series is the Model 30 286 variant.

IBM PS/2 Model 30 submodels
Submodel CPU RAM FDD HDD Video Bus Notes
8530-002 Intel 8086 @ 8 MHz 640 KB 2 × 720 KB none MCGA ISA 8-bit Base 1987 configuration, US $2,295
8530-021 Intel 8086 @ 8 MHz 640 KB 1 × 720 KB 20 MB ST-506 MCGA ISA 8-bit With hard drive, US $3,495
8530-E01 Intel 80286 @ 10 MHz 512 KB (4 MB max) 2 × 1.44 MB none VGA ISA 16-bit Model 30 286, 1988
8530-E21 Intel 80286 @ 10 MHz 1 MB (4 MB max) 1 × 1.44 MB 20 MB VGA ISA 16-bit Model 30 286 with HDD
8530-E31 Intel 80286 @ 10 MHz 1 MB (4 MB max) 1 × 1.44 MB 30 MB VGA ISA 16-bit Model 30 286, larger HDD
8530-E41 Intel 80286 @ 10 MHz 1 MB (4 MB max) 1 × 1.44 MB 45 MB VGA ISA 16-bit Model 30 286, latest configuration

Architecture

edit

Model 30 8086 planar

edit

The Model 30 8086 planar (silkscreened part-numbers in the IBM 23F/72X range) is closely related to the Model 25 8086 planar — the two units share a common ISA + MCGA + PS/2-port architecture, and an 8530 8086 planar can be physically and electrically swapped with an 8525 8086 planar. Key chips:

  • Intel 8086 (or compatible AMD R80C86) at 8 MHz with zero wait states from on-board DRAM.
  • Three ISA expansion slots on a riser card.
  • Three IBM-fabricated PS/2 gate-array support chips (72X8202 / 72X8203 / 72X8206 family) handling CPU/bus glue, planar I/O and integrated MCGA video.
  • Intel P8253-5 programmable interval timer.
  • NEC D765AC-2 floppy disk controller for the PS/2 single-cable diskette interface.
  • Siemens 8237A DMA controller (one, not the dual pair used on the AT).
  • NS8250AV UART for the integrated serial port.
  • Intel 8042 keyboard/mouse controller driving the PS/2 (Mini-DIN-6) keyboard and pointing-device ports.
  • Inmos IMSG171P video RAMDAC.
  • Two 32 KB EPROM sockets carrying the 64 KB BIOS (split between CBIOS and ABIOS).
  • ROM BASIC is not provided — the BIOS prompts for a boot diskette if no boot device is found.
  • No hardware RTC and no battery-backed CMOS on the original 8086 planar: date and time are set manually at every boot from DOS.
  • Single MMK 30-pin SIMM socket for memory expansion to 640 KB; the on-board DRAM provides the lower 512 KB.

The Model 30 8086 PSU is rated 70 W, 110/220 VAC switchable, with the proprietary PS/2 single-cable drive power+data combined feed (no Molex). The IBM Model 55 PSU is a drop-in replacement.

Model 30 286 planar

edit

The Model 30 286 planar (8530-E series) is an architectural relative of the Model 25 286 planar — both use a VLSI VL82C100 / 101 / 102 / 103 / 104 "Popular AT" chipset, the VLSI VL16C451 integrated UART + parallel port, the NEC D765BC FDC, the Intel 8042 keyboard controller, an IBM 15F6864 VGA gate array and the IMSG171P RAMDAC. Key differences from the 8086 planar:

  • Intel 80286 @ 10 MHz, 1 wait state to memory.
  • Two 30-pin MMK parity SIMM sockets — 512 KB modules each, expandable to 4 MB total.
  • ISA 16-bit expansion on the riser (vs ISA 8-bit on the 8086 Model 30). Three slots.
  • Auxiliary 4-pin power connector supplies +12 V to the 16-bit ISA bus — this connector is present on the Model 30 286 and absent on the 8086 Model 30.
  • VGA video integrated on the planar with the IBM 15F6864 VGA gate array and IMSG171P RAMDAC, exposed on the standard 15-pin DSUB at the rear.
  • Battery-backed hardware RTC (Dallas DS1287 / DS12887 or equivalent) provides the date/time and stores CMOS configuration. This is the same battery family used in the Model 25 286 and Model 25 SX.
  • 80287 math coprocessor socket near the 80286 CPU.

The Model 30 286 PSU is rated 70 W (some sources cite 80 W for late E-series units), 110/220 VAC switchable, with the additional 16-bit ISA aux power connector.

Memory

edit

The Model 30 memory subsystem differs between the two generations:

  • Model 30 8086: 512 KB on the planar, expandable to 640 KB via one 128 KB IBM memory module (IBM P/N 78X8955 family) at a proprietary 30-pin DIP/SMK RAM socket. The architectural ceiling is the 640 KB IBM PC limit.
  • Model 30 286: 512 KB on the planar with one PS/2-pinout MMK 30-pin parity SIMM socket (or 1 MB factory-fit on -E21 onwards). Two SIMM sockets total; the maximum supported is 4 MB (2 × 2 MB MMK SIMMs). Modules must have the IBM-specific pinout — standard PC-AT 30-pin SIMMs may fit physically but are not recognised by the BIOS.

The MMK SIMM is similar in geometry to standard 30-pin SIMMs but uses different chip-select routing and is not interchangeable with PC-AT-class parity SIMMs.

Display

edit

The Model 30 8086 uses MCGA — the same integrated video controller as the Model 25 8086. MCGA supports the standard CGA modes plus two MCGA-specific modes:

Model 30 8086 MCGA video modes
Mode Resolution Colours Refresh
0/1 40×25 text 16 70 Hz
2/3 80×25 text 16 70 Hz
4/5 320×200 4 70 Hz (CGA-compatible)
6 640×200 2 70 Hz (CGA-compatible)
0x11 640×480 2 60 Hz (MCGA-specific)
0x13 320×200 256 70 Hz (MCGA-specific)

Total palette: 262,144 colours. MCGA drives analog monitors only (15-pin DSUB connector) and is not compatible with TTL digital CGA or MDA monitors.

The Model 30 286 has full VGA integrated on the planar — the same VGA chipset family used in the Model 25 286. Modes include all of MCGA's plus the standard VGA 16-colour 640×480 graphics mode and the additional text modes.

Storage and Expansion

edit
  • Floppy interface: PS/2 single-cable, carrying both power and data on one ribbon. Same as Model 25. Drives are typically ALPS, Mitsubishi, Sony or YE-Data. The Model 30 8086 BIOS only supports 720 KB diskettes natively, though specific Sony 1.44 MB drives are documented to work. The Model 30 286 supports 1.44 MB natively.
  • Hard drive interface (Model 30): Proprietary planar-integrated ST-506 controller. Different from later MCA models' ESDI. Setup disk does not offer alternative drive types — only two or three specific drive part numbers will work. The drive sits in a caddy.
  • Expansion bus: Three ISA slots on a riser card. 8-bit on the Model 30, 16-bit on the Model 30 286.
  • No MCA — the Model 30 is the only original PS/2 (along with the Model 25) that uses ISA.

Keyboard and Mouse

edit

The Model 30 introduces the PS/2 keyboard connector (Mini-DIN-6) and the PS/2 mouse port. The two connectors are functionally identical at the 8042 controller level but the BIOS expects each device on its designated port; swapping them produces a 301 error at POST.

Default keyboards are the IBM Space-Saving Keyboard (P/N 1391472, 84-key) or the Enhanced Keyboard (P/N 1391406, 101-key Model M).

BIOS and Reference Diskette

edit

The Model 30 BIOS is the standard PS/2 split CBIOS / ABIOS architecture:

  • CBIOS (Compatible BIOS) for backward-compatible DOS support.
  • ABIOS (Advanced BIOS) for OS/2 protected-mode operation.

There is no built-in SETUP screen. Configuration is performed by booting the model-specific IBM PS/2 Reference Diskette. The Model 30 8086 and the Model 30 286 have different Reference Diskettes; they are not interchangeable, and neither is interchangeable with the Model 25, Model 50, or higher-model PS/2 Reference Diskettes.

The Reference Diskette includes:

  • SETUP — configures memory size, drive types, date/time (Model 30 286 only), display and mouse.
  • Advanced Diagnostics (entered with Ctrl-A) — full hardware test suite.

Power Supply

edit

The Model 30 uses a proprietary 70 W PS/2 power supply with single-cable drive outputs and direct connections to the planar. Power connectors are not Molex 4-pin. The Model 30 286 adds a 4-pin auxiliary connector for the 16-bit ISA bus.

The IBM Model 55 PSU is a drop-in replacement for the Model 30 PSU.

General Maintenance

edit

PSU rail checks, RTC battery replacement on the Model 30 286, planar inspection, PS/2 connector care and floppy / hard drive maintenance are documented in IBM PS/2 Model 30 Maintenance Guide.

Troubleshooting

edit

Audio beep codes, the complete PS/2 numeric POST error code reference, Reference Diskette procedures, dead-system isolation, ECA recalls and Model-30-specific quirks are documented in IBM PS/2 Model 30 Troubleshooting Guide.

Capacitor Replacement

edit

Tantalum failure on the planar, PSU electrolytic ageing and the drive logic board are documented in IBM PS/2 Model 30 Capacitor Replacement Guide.

edit
  •  
    IBM PS/2 Model 30 (8530) system unit
  •  
    PS/2 Model 30 286 (8530-E series) front view
  •  
    Model 30 286 with top cover removed
  •  
    Front-panel badge from the 8086 Model 30
  •  
    Front-panel badge from the Model 30 286
edit

References

edit
  • IBM PS/2 Model 30 — Wikipedia. Source for release dates, submodel list, MCGA/VGA video distinction and chronology.
  • IBM PS/2 Model 30 — DOS Days. Source for submodel pricing, hardware compatibility, ISA bus distinction, PSU rating (70 W), proprietary ST-506 hard drive interface, single Sony 1.44 MB drive compatibility, dimensions (406 × 397 × 102 mm), weight (~8 kg).
  • IBM PS/2 Model 30 — Technical Specifications, Ardent Tool of Capitalism (IBM document GJAN-43VKBR). Source for the 8086 / 286 planar architectures, MMK SIMM details, and option-card list.
  • IBM, IBM Personal System/2 Hardware Maintenance Reference (S52G-9971 series, October 1994). Authoritative source for FRU listings.


Retrieved from "https://wiki.retrotechcollection.com/index.php?title=IBM_PS/2_Model_30&oldid=11030"