IBM PS/2 Model 70
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| IBM PS/2 Model 70 386 (8570) | |
| Specifications | |
|---|---|
| Manufacturer | IBM |
| Type | Desktop personal computer |
| Released | 2 June 1988 (E61, 121, A21) |
| Intro price | US$5,995 (E61), US$7,995 (121), US$11,295 (A21) at launch[1][2] |
| CPU | Intel 80386 at 16 MHz (E61), 20 MHz (061, 081, 121, 161) or 25 MHz with a 64 KB cache (A-models); Intel 80486 at 25 MHz (Model 70 486, B-models) |
| Memory | 1, 2 or 4 MB as shipped; 6 MB on the 16 and 20 MHz system boards, 8 MB on the 25 MHz boards; 16 MB system maximum |
| Storage | 1.44 MB 3.5-inch diskette drive; 60, 80, 120 or 160 MB fixed disk with integrated controller |
| Display | VGA on the system board, 256 KB video memory |
| Sound | Speaker |
| Dimensions | 360 × 420 × 140 mm (W × D × H)[3] |
| Weight | 9.55 kg[3] |
| OS / Firmware | IBM DOS 3.30; OS/2 Standard and Extended Editions; AIX PS/2[1] |
| Model no. | 8570 |
The IBM Personal System/2 Model 70 386 (machine type 8570) is a desktop computer with an Intel 80386 and IBM's Micro Channel bus, announced on 2 June 1988.[1] It uses the chassis of the IBM PS/2 Model 50, with a 132 W supply, three Micro Channel slots (two of them 32-bit) and a fixed disk with its controller built in.[1][4] A 25 MHz model with a 64 KB cache, the A21, was announced the same day; the 486/25 Power Platform upgrade and the Model 70 486 followed in 1989, and 4 MB models with 80 MB and 160 MB drives in 1991.[2][5][6][7][8]
Models
[edit | edit source]| Submodel | Processor | Memory as shipped | Fixed disk | Announced | US price |
|---|---|---|---|---|---|
| 8570-E61 | 80386, 16 MHz | 1 MB | 60 MB | 2 June 1988 | $5,995 |
| 8570-121 | 80386, 20 MHz | 2 MB | 120 MB | 2 June 1988 | $7,995 |
| 8570-A21 | 80386, 25 MHz, 64 KB cache | 2 MB | 120 MB | 2 June 1988 | $11,295 |
| 8570-061 | 80386, 20 MHz | 2 MB | 60 MB | 26 September 1989 | $5,795 |
| 8570-A61 | 80386, 25 MHz, 64 KB cache | 2 MB | 60 MB | 26 September 1989 | $8,395 |
| 8570-B61 | 80486, 25 MHz | 2 MB | 60 MB | 19 December 1989 | $12,390 |
| 8570-B21 | 80486, 25 MHz | 2 MB | 120 MB | 19 December 1989 | $12,990 |
| 8570-081 | 80386, 20 MHz | 4 MB | 80 MB | 11 June 1991 | $4,095 |
| 8570-161 | 80386, 20 MHz | 4 MB | 160 MB | 11 June 1991 | $4,745 |
| 8570-A81 | 80386, 25 MHz, 64 KB cache | 4 MB | 80 MB | 11 June 1991 | $5,845 |
| 8570-A16 | 80386, 25 MHz, 64 KB cache | 4 MB | 160 MB | 11 June 1991 | $6,445 |
Sources: IBM's announcement letters.[1][2][6][7][8] IBM's 1994 manual also lists B81 and B16 486 models.[9]
System boards
[edit | edit source]IBM's Technical Reference identifies four system-board types by their model and submodel bytes:[3]
| IBM type | Model / submodel byte | Processor | Memory sockets | System-board memory | Cache |
|---|---|---|---|---|---|
| Type 1 | F8 / 09 | 80386, 16 MHz, on the board | Three 72-pin | 1 to 6 MB | None |
| Type 2 | F8 / 04 | 80386, 20 MHz, on the board | Three 72-pin | 1 to 6 MB | None |
| Type 3 | F8 / 0D | 80386, 25 MHz, on a processor card | Four 72-pin | 2 to 8 MB | 64 KB, 82385 controller |
| Type 4 | F8 / 1B | 80486, 25 MHz, on a processor card | Four 72-pin | 2 to 8 MB | 8 KB inside the 80486 |
The 16 and 20 MHz boards were also built in two layouts, which IBM calls full size and reduced size.[10] Ardent Tool's pages call these layouts "Type 1" (long) and "Type 2" (short), which is not IBM's numbering.[11][12] IBM's 1994 parts list gives the system-board FRU by submodel and serial-number range: 96F7309 or 41G3984 for the 16 MHz E61, 96F7308 or 41G3985 for the 20 MHz 061 and 121, 41G3985 for the 081 and 161, 92F0580 with processor board 15F7659 for the 25 MHz 386 models, and 41G3979 with processor board 64F0123 for the 486 models.[9]
| Device | Full-size 16/20 MHz board | Reduced-size 20 MHz board | 25 MHz board |
|---|---|---|---|
| Processor | U143 (80386) | U20 (socket) | On the processor card in J15 |
| 80387 socket | U148 | U42 | On the processor card |
| Real-time clock and CMOS RAM | U150 MC146818A | U81 MC146818AFN | U143 MC146818AFN |
| Static RAM | U145 µPD446G-20L (2K × 8) | U79 HM6264LFP-15T (8K × 8) | U123 HM6264ALFP-15T (8K × 8) |
| VGA controller | U15 15F6864 | U61 90X8941 | U20 15F6864 |
| RAMDAC | U2 IMSG171 | U68 IMSG171 | U15 IMSG171 |
| Memory sockets | J30 to J32 | J7, J9, J10 | J17, J18, J20, J21 |
| 32-bit channel connectors | J2, J3 | J11, J12 | J2, J3 |
| 16-bit channel connector with video extension | J1 | J13 | J1 |
| Drive riser connector | J34 | J5 | J16 |
| Power supply edge connector | J36 | J1 | J14 |
| Battery and speaker connector | J19 (card edge) | J14 (header) | J19 (card edge) |
Sources: Ardent Tool's planar maps, which identify U145 and U79 as the chips holding the Micro Channel configuration.[11][12][13] The 25 MHz 386 processor card (FRU 15F7659) carries the 386DX-25, a 387DX-25 socket, the 82385-25 cache controller and eight 8K × 8 SRAMs; the 486 card (FRU 64F0123) carries only the 486DX-25 and a 50 MHz oscillator.[13][9] On the 25 MHz machines, IBM's snap tool 57F2859 also separates the processor card from the system board.[10]
The system board has 128 KB of ROM, 64 bytes of CMOS RAM with the real-time clock plus a 2 KB CMOS RAM extension, VGA with 256 KB of video memory, eight DMA channels, 16 level-sensitive interrupt levels, the keyboard and auxiliary-device controller with password security, a diskette controller for 720 KB and 1.44 MB media, a serial port with FIFO mode and a bidirectional parallel port.[3] The BIOS is split into a compatibility BIOS (CBIOS) that addresses up to 1 MB and an advanced BIOS (ABIOS) that addresses up to 16 MB.[1]
Micro Channel
[edit | edit source]There are three channel connectors: one 16-bit connector with the auxiliary video extension, and two 32-bit connectors with the matched-memory extension.[3][1] IBM's load limit is 1.6 A at +5 V for the 16-bit connector and 2.0 A for each 32-bit connector, with 0.175 A at +12 V and 0.040 A at −12 V on each.[3] Section 1.0 of IBM's Model 70 Hardware Maintenance Reference lists "two 16-bit expansion slots" and a 90 W supply; the same manual's board diagrams, the Technical Reference and the announcements give two 32-bit slots and 132 W.[10][3][1]
Memory
[edit | edit source]The 16 and 20 MHz boards take up to three 72-pin parity modules (6 MB with three 2 MB kits); the 25 MHz boards take four (8 MB). With Micro Channel memory adapters in the 32-bit slots the system supports 16 MB.[10][1][2] IBM sold 85 ns 1 MB and 2 MB kits for the 16 and 20 MHz boards, and a 2 MB 80 ns kit (#5214) for the 25 MHz boards, on which the 85 ns kits must not be used.[1][2][6] Ardent Tool's contributors report that on the 25 MHz board the modules should be fitted from J21 and J20 first; one reports 215 errors when starting at J17 or J18.[13] Tim O'Connor, on Ardent Tool, puts the 16 MB ceiling down to the Micro Channel DMA controller's 24 address lines.[14]
The Model 70 manages memory in 1 MB blocks. An error in the first 512 KB of system-board memory disables the first 1 MB block and moves its addresses to the second block if one is fitted. An error elsewhere is reported, and the customer diagnostics on the Reference Diskette can then disable that block so that later starts ignore it.[10]
Video
[edit | edit source]The VGA is on the system board, with 256 KB of video memory. It supports 640 × 480 in 16 colours, 320 × 200 in 256 colours and 720 × 400 text, and is compatible with CGA and EGA modes. The 16-bit slot with the auxiliary video extension takes adapters that work with the on-board VGA.[1][10]
Storage
[edit | edit source]Diskette
[edit | edit source]The machine ships with one 1.44 MB 3.5-inch drive and has a position for a second.[1] Both drives and the fixed disk plug into a drive riser in the system board's 56-pin drive connector; IBM's 1994 FRUs are 64F0207 for the diskette drive and 90X9287 for the bus adapter, and Ardent Tool records riser FRU 90X1111, with two diskette connectors and the fixed-disk connector.[10][9][15] PS/2 3.5-inch drives are direct drive, with no belt; their usual fault is failed surface-mount electrolytics on the drive board.[16][17]
Fixed disk
[edit | edit source]The fixed disk has its controller built in and plugs straight into the drive riser through a 2 × 36-pin edge connector, which carries a subset of the 16-bit Micro Channel. The subset omits the top eight address lines.[1][18] The controller appears to the Reference Diskette as adapter ID DF9F, "Integrated Fixed Disk and Controller".[14] Peter Wendt describes these drives as technically MFM RLL 2,7 drives with the controller built in, which IBM's BIOS treats as ESDI.[19] The drives park their heads automatically when the power is switched off.[10]
| Capacity | IBM FRU | Cylinders | Heads | Sectors per track | Transfer rate | Average access |
|---|---|---|---|---|---|---|
| 60 MB | 6128294 | 762 | 6 | 26 | 8.4 Mbit/s | 27 ms |
| 80 MB | 56F8894 | Announced 1991 | ||||
| 120 MB | 6128291 | 920 | 8 | 32 | 10.2 Mbit/s | 23 ms |
| 160 MB | 56F8895 | Announced 1991 | ||||
Sources: IBM's announcements and 1994 parts list.[1][8][9]
Power supply
[edit | edit source]The supply is an ASTEC AA15530, IBM P/N 90X9409, FRU 90X8626, rated 132 W, with an automatic 100–125 V / 200–240 V input and its own fan.[15][1][9] It plugs into a 50-pin edge connector on the system board, the same pinout as the Model 50's 94 W supply, and gives +5 V, +12 V and −12 V to the system board, and +5 V and +12 V to the drives.[15][3] A short on any output, or an internal overvoltage before any output reaches 130 % of nominal, latches all outputs off until the fault is removed and the power switch has been off for at least ten seconds.[3] The supply raises Power Good, and lights the green power-good light on the front, only when the outputs are above +4.5 V, +10.8 V and −10.2 V.[10] Ardent Tool records two 5 A 250 V fast-blow fuses, F1 and F2, one in each mains line.[15]
IBM figures from the Technical Reference: heat output 215 W (735 BTU per hour); input 90–137 V or 180–265 V AC; 0.13 kVA as shipped and 0.36 kVA fully configured; 275 mA for the keyboard and 300 mA for the auxiliary device.[3] The announcement gives a maximum draw of 4 A at 100–125 V and 2 A at 200–240 V.[1]
Clock and battery
[edit | edit source]The clock is a Motorola MC146818A soldered to the system board, with a 32.768 kHz crystal. The 2 KB CMOS RAM extension that holds the rest of the configuration is a separate static RAM.[11][12][13][10] A 6 V lithium battery, IBM part 72X8498, in battery and speaker assembly 33F5950, keeps them running when the supply is off.[9][10] The assembly plugs into a card-edge connector on the full-size and 25 MHz boards and a 6-pin header on the reduced-size board.[20] IBM retain tip H024809, filed for the Models 60, 65 SX and 80, which use the same battery and assembly, says to replace the battery if it reads below 5.5 V DC out of the assembly.[21]
Chassis
[edit | edit source]The case is 360 mm wide, 420 mm deep and 140 mm high and weighs 9.55 kg.[3] The cover is held by captive screws at the rear; loosen them, slide the cover forward about two inches and lift it off. Peter Wendt's method for a locked case is to push the cover forward, then open a 4 to 5 mm gap between the cover and the rear wall with a large screwdriver and slide the cover over the locking tab.[4] Four posts on the drive support structure carry the weight of a monitor on the lid down to the base.[4]
Upgrades
[edit | edit source]The 486/25 Power Platform (feature 5220, part 6450876, US$3,995, announced 20 June 1989) replaces the 386 processor card of a 25 MHz Model 70 with an 80486 card and includes two EPROMs that update the system-board firmware. At announcement it was for the A21 only; IBM later listed it for the A61, A81 and A16.[5][6][8] The 486 card has no external cache; the 80486 has an internal 8 KB cache and floating-point unit.[13][7] Ardent Tool notes that every known 486 processor card has yellow rework wires fitted at the factory.[13] IBM's 1994 manual also lists a 486DX33 processor upgrade card (FRU 92F0436) and 486DLC2 and 486DX33 system boards (FRUs 71G2606 and 71G2641) for the Model 70.[9]
Documentation
[edit | edit source]- IBM PS2 Model 70 Technical Reference (May 1988) and IBM PS2 Model 70 Technical Reference (October 1990): IBM's hardware references; the October 1990 edition covers all four system-board types.
- IBM PS2 Model 70 Hardware Maintenance Reference (S64F-3993-00, March 1990): removal procedures, locations, power-good sense levels and memory rules.
- IBM Personal System 2 Hardware Maintenance Manual (S52G-9971-02, October 1994): the Micro Channel checkout and error codes, voltage checks (p. 141), system-board locations (pp. 203–205) and the Model 70 parts list (pp. 254–256).
Known faults
[edit | edit source]- Lost configuration, a clock that stops, or 161 and 163 at POST: the battery or its assembly. See the IBM PS/2 Model 70 Maintenance Guide.[21]
- Diskette errors and 6xx codes: failed capacitors on the drive board, or a sticking head carriage. See the IBM PS/2 Model 70 Capacitor Replacement Guide.[17]
- A fixed disk that will not spin up after storage: stuck heads. Peter Wendt names the Seagate ST-177I 60 MB drive in some Model 70-061 machines as prone to it.[22]
- 104xx fixed-disk errors: IBM's list for the read/write group is Advanced Diagnostics, then the riser card, the drive and the system board.[9]
- IBM's engineering changes for the 25 MHz board, as recorded by Ardent Tool: ECA 021, a replacement system board (P/N 15F7657) for an A21 that shows a 110 error with five question marks after a memory upgrade; ECA 029, the same board for 25 MHz machines with bus-master problems whose board barcode starts B1HC"A" to B1HC"H"; and ECA 092, a data modification patch for 25 MHz machines with 80 MB or 160 MB drives under DOS or OS/2.[13]
- A machine that hangs at start-up with the mouse connected: in one case on Ardent Tool, Jim Shorney traced it to the keyboard, which shares the controller with the mouse port; he also suggests cleaning dust out of the system board and supply.[14]
Troubleshooting is in the IBM PS/2 Model 70 Troubleshooting Guide.
Gallery
[edit | edit source]-
Model 70 386, front -
Model 70 with the cover off, showing the battery and speaker assembly and the drive riser -
25 MHz system board with its processor card, and the supply and fan assembly -
Reduced-size 20 MHz system board from an 8570-121, fitted with an Intel RapidCAD -
Model 70 386 badge -
Model 70 486 badge
Related pages
[edit | edit source]- IBM PS/2 Model 70 Maintenance Guide
- IBM PS/2 Model 70 Troubleshooting Guide
- IBM PS/2 Model 70 Capacitor Replacement Guide
- IBM PS/2 Model 50
- IBM PS/2 Model 80
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 IBM Announcement Letter 188-079, IBM Personal System/2 Model 70 386 (8570 E61/121), 2 June 1988, text at ardent-tool.com. Prices; 16 or 20 MHz 80386; up to 6 MB on the system board and 16 MB in total; fixed disks with integrated controller and their geometry; VGA modes; CBIOS and ABIOS; three slots ("two 32-bit bus slots and one 16-bit bus slot with video extension"); 132 W automatic voltage-sensing supply; battery-backed clock; second diskette position; 85 ns memory kits; dimensions, weight (9.5 kg) and electrical input; DOS 3.30, OS/2 Standard and Extended Editions, AIX PS/2.
- ↑ 2.0 2.1 2.2 2.3 2.4 IBM Announcement Letter 188-078, IBM Personal System/2 Model 70 386 (8570-A21), 2 June 1988, text at ardent-tool.com. US$11,295; 82385 cache controller and 64 KB cache; up to 8 MB on the system board; the 2 MB 80 ns kit (#5214) for the A21 only, and the instruction not to use the 85 ns kits on the A21 system board.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 IBM, IBM Personal System/2 Model 70 386 Technical Reference, October 1990. Hosted on this wiki as IBM PS2 Model 70 Technical Reference (October 1990) (PDF). Description and system-board types, p. 1-3; model and submodel bytes, Figure 1-1; system board devices and features, Figures 1-2 to 1-4; physical specifications, Figure 1-10; power supply, outputs, component maximum current and channel load current, Figures 1-12 and 1-13; output protection.
- ↑ 4.0 4.1 4.2 Ardent Tool of Capitalism, "8550 and 8570 – Common Devices". Opening and closing the case; Peter Wendt on opening a locked unit; the weight-transfer posts; removing the planar.
- ↑ 5.0 5.1 IBM Announcement Letter 189-102, IBM Personal System/2 486/25 Power Platform, 20 June 1989, text at ardent-tool.com. Feature 5220, part 6450876, US$3,995; i486 with internal cache controller, 8 KB cache and floating-point unit; "can be installed on the 8570-A21 only".
- ↑ 6.0 6.1 6.2 6.3 IBM Announcement Letter 189-144, New Models of IBM Personal System/2 Model 70 386 (8570-061 and 8570-A61), 26 September 1989, text at ardent-tool.com. Prices US$5,795 and US$8,395; system-board memory to 6 MB (061) or 8 MB (A61); 80 ns kit for the A21 and A61; Power Platform for the A61 and A21.
- ↑ 7.0 7.1 7.2 IBM Announcement Letter 189-196, Personal System/2 Model 70 486 (8570-B61 and 8570-B21), 19 December 1989, text at ardent-tool.com. Prices US$12,390 and US$12,990; 25 MHz i486 with internal cache controller, 8 KB cache and floating-point unit; system-board memory to 8 MB.
- ↑ 8.0 8.1 8.2 8.3 IBM Announcement Letter 191-079, IBM Personal System/2 Model 70 386 (081, 161, A81 and A16), 11 June 1991, text at ardent-tool.com. 4 MB standard; 80 MB and 160 MB drives with integrated controller; prices US$4,095, US$4,745, US$5,845 and US$6,445; the Power Platform for the A81 and A16.
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 IBM, IBM Personal System/2 Hardware Maintenance Manual, S52G-9971-02, October 1994. Hosted on this wiki as IBM Personal System 2 Hardware Maintenance Manual (S52G-9971-02, October 1994) (PDF). ESDI error codes, pp. 46–48; processor upgrades, p. 137; Model 70 parts (power supply and fan 90X8626, battery/speaker assembly 33F5950, battery 72X8498, system and processor boards by serial number, 486DX33 upgrade 92F0436, bus adapter 90X9287, diskette drive 64F0207, fixed disks), pp. 255–256; system specifications, p. 436.
- ↑ 10.00 10.01 10.02 10.03 10.04 10.05 10.06 10.07 10.08 10.09 10.10 IBM, IBM PS/2 Model 70 Hardware Maintenance Reference, S64F-3993-00, March 1990. Hosted on this wiki as IBM PS2 Model 70 Hardware Maintenance Reference (PDF). Product description, 1.0; CMOS RAM and extension, 1.2.2; VGA, 1.2.4; diskette controller, 1.2.7; fixed disks park their heads, 2.2; power supply and under-voltage sense levels, 3.1; system-board memory and memory errors, 3.3.1 and 3.3.4; snap tools 72X8547 and 57F2859, 5.0; battery caution, 6.3; full-size, reduced-size and 25 MHz system-board locations, 7.4 to 7.6.
- ↑ 11.0 11.1 11.2 Ardent Tool of Capitalism, "8570 Type 1 Planar". Designator map of the full-size 16/20 MHz board (FRU 96F7309 or 41G3984); U150 MC146818A and U145 µPD446G-20L; Model 70 386 Reference Disk v1.12.
- ↑ 12.0 12.1 12.2 Ardent Tool of Capitalism, "8570 Type 2 Planar". Designator map of the reduced-size 20 MHz board (FRU 96F7308 or 41G3985), including F1 keyboard/mouse fuse, U81 MC146818AFN and U79 HM6264LFP-15T.
- ↑ 13.0 13.1 13.2 13.3 13.4 13.5 13.6 Ardent Tool of Capitalism, "8570 Type 3 & 4 Planar". The 25 MHz board (FRU 92F0580 for 386, 41G3979 for 486); J15 processor card socket; memory notes; ECAs 021, 029 and 092; the 386 processor card (FRU 15F7659) and 486 card (FRU 64F0123) with its rework wires; Model 70 486 Reference Disk v1.06; the Power Platform kit's two EPROMs.
- ↑ 14.0 14.1 14.2 Ardent Tool of Capitalism, "8570 – Common Devices". Tim O'Connor on memory and the 16 MB limit; the integrated fixed disk and controller ADF (adapter ID DF9F); Jim Shorney on a machine that hung with the mouse connected.
- ↑ 15.0 15.1 15.2 15.3 Ardent Tool of Capitalism, "8550 / 8570 / 756x – Power Supply". Common 50-pin pinout for the 8550 (94 W) and 8570 (132 W); 8570 supply ASTEC AA15530, IBM P/N 90X9409, FRU 90X8626, with per-pin currents; fuses F1 and F2, 5 A 250 V fast-blow; riser card FRU 90X1111.
- ↑ Mitsubishi Electric, 3.5 inch Flexible Disk Drive Standard Specifications, MF355C, UGD-0527A, February 1987. Hosted on this wiki as File:Mitsubishi MF355C 3.5 inch Diskette Drive Specifications (UGD-0527A, Feb 1987).pdf. Section 3: brushless DC direct-drive spindle motor at 300 rpm.
- ↑ 17.0 17.1 Ardent Tool of Capitalism, "8580 Diskette Drives", content by Fred Spencer and Al Savage. Surface-mount electrolytic failures on PS/2 diskette drives; mechanical causes of a 162.
- ↑ Ardent Tool of Capitalism, "IBM DBA-ESDI Hard Drives". The Model 70 drive riser connector; the 2 × 36-pin edge-connector pinout from the Model 70 Technical Reference; the omission of the top eight address lines.
- ↑ Ardent Tool of Capitalism, "8550 HDD Adapters". Peter Wendt on the IBM integrated hard disk adapter (card ID DF9F) in the 50 Z, 55 SX, 70 and P70.
- ↑ Ardent Tool of Capitalism, "Battery/Speaker Assembly". Header and card-edge connector versions and pinouts; the power-on password override.
- ↑ 21.0 21.1 Ardent Tool of Capitalism, "60, 65 SX, and 80 – Common Devices". IBM retain tip H024809: battery 72X8498 in speaker/battery assembly 33F5950; replace below 5.5 V DC.
- ↑ Ardent Tool of Capitalism, "Known Problems – Experience, RETAIN Tips, ECAs". Peter Wendt on hard-disk stiction and the Seagate ST-177I.