Sega Saturn (Model 1)
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| A North American first-generation Saturn with the original control pad | |
| Specifications | |
|---|---|
| Manufacturer | Sega Enterprises, Ltd. |
| Type | Home video game console |
| Released | 22 November 1994 (Japan) 11 May 1995 (North America) 8 July 1995 (Europe)[1] |
| Discontinued | 1998 (North America)[1] |
| Intro price | ¥44,800 (Japan); US$399 (North America, with Virtua Fighter); £399.99 (Europe)[1] |
| CPU | Two Hitachi SH-2 (32-bit RISC); 68EC000 at 11.3 MHz for sound[2] |
| Memory | Work RAM 16 Mbit; video RAM 12 Mbit; sound RAM 4 Mbit; CD buffer 4 Mbit; IPL ROM 4 Mbit; backup RAM 256 kbit[2] |
| Storage | Double-speed CD-ROM drive; battery-backed RAM; cartridge slot[2] |
| Display | 320 × 224 and other modes[2] |
| Sound | 32 channels, PCM and FM, 16-bit, up to 44.1 kHz[2] |
| Dimensions | 260 × 230 × 83 mm[2] |
| OS / Firmware | IPL ROM, 4 Mbit |
| Predecessor | Sega Mega Drive / Genesis (Model 2) |
| Successor | Sega Saturn (Model 2) |
| Model no. | HST-3200, HST-3210 (Japan); MK-80000 (North America); MK-80200-50 (Europe)[3][2] |
The Sega Saturn is Sega's CD-based console, released in Japan in November 1994 and in North America and Europe in 1995.[1] The Model 1 is the original design: in Japan the grey HST-3200 and its revision the HST-3210, and abroad the black MK-80000 (North America) and MK-80200-50 (Europe). The cheaper HST-3220 of March 1996 and its overseas equivalents are the Model 2.[3] Sega's PAL service manual covers the MK-80200-50.[2]
The Model 1 has separate Power and Access lamps. On the first HST-3200 the CD subsystem (the SH-1 CPU, its gate array and the CD buffer DRAM) is on a separate board above the main board; the HST-3210 moved it onto the main board.[3] Sega's PAL manual documents the two-board arrangement, with an SH-1 board (838-10834) carrying the SH-1 at IC101, the CD buffer DRAM at IC102 and the OCU gate array at IC103.[4]
Power
[edit | edit source]The Saturn runs from the mains through a power supply inside the case. The PAL MK-80200-50 is rated AC 220-240 V, 50/60 Hz, about 20 W;[2] North American machines are AC 120 V 60 Hz.[3] Sega lists the PAL supply as "AC power unit Saturn EUR" (400-5271 or 400-5272), with a 1.6 A fuse (514-5066) and the mains inlet marked as safety-critical parts, and supplies a detachable mains lead for the UK, for other European countries and for Australia.[4] Console5 lists supplies from Fujitsu, Panasonic, Phihong, Voltek and Yamaha across the production run.[5]
Warning: the power supply carries mains voltage and its primary reservoir capacitor can hold a charge after unplugging. Unplug the console and leave it before working on the supply.
The supply feeds the main board through CN3 with three rails, as Sega's block diagram labels them:[6]
| Rail | Use on Sega's block diagram |
|---|---|
| +9 V | CD drive, and the PLL |
| +5 V (VCC, AVCC2) | All chips other than the SDRAM |
| +3.3 V (LVCC) | SDRAM |
There is also a µPC78L05 or TA78L05 regulator at IC34 on the main board.[4] The position silkscreened FUSE on the VA0 PAL main board is fitted with a 10 mm jumper wire (Sega part 600-6458), not a fuse.[4]
Specification
[edit | edit source]From Sega's ratings and specification tables for the PAL machine.[2]
| Item | Figure |
|---|---|
| Model | MK-80200-50 |
| Power supply | AC 220-240 V, 50/60 Hz |
| Power consumption | Approximately 20 W |
| Operating environment | 5 to 35 °C, 10 to 80% RH, non-condensing |
| Dimensions | 260 (W) × 230 (L) × 83 (H) mm |
| CPUs | Master and slave SH-2, 32-bit RISC, 28.4 MHz, 25 MIPS; sound 68EC000, 11.3 MHz |
| Memory | Work RAM 16 Mbit; video RAM 12 Mbit; sound RAM 4 Mbit; CD buffer RAM 4 Mbit; IPL ROM 4 Mbit; backup RAM 256 kbit |
| Graphics | 320 × 224 and other resolutions; 1024/2048 colours from 16,770,000; sprite enlargement, reduction, rotation and transformation |
| Scroll screens | Up to five: four XY scroll, two rotation, two enlargement/reduction, two windows |
| 3D | Dedicated polygon hardware; wire frame, flat and Gouraud shading |
| Sound | PCM and FM, 32 channels, 16-bit, sampling up to 44.1 kHz, audio DSP |
| CD-ROM | Double-speed drive |
The 28.4 MHz in the specification table is the PAL figure. The PAL parts list fits a 17.7344 MHz crystal at X1,[4] while the block diagram in the same manual shows a 14.318 MHz clock and a 28.6 MHz SH-2, which are the NTSC figures.[6] English Wikipedia gives 28.6 MHz.[1]
Main board, VA0
[edit | edit source]Sega's parts list for the VA0 main board, with the functions from the block diagram.[4][6]
| Position | Device | Function |
|---|---|---|
| IC1, IC2 | HD6417095F28 or HD6417095SF28 (Hitachi SH-2) | Master and slave CPUs |
| IC3, IC4 | 4 Mbit SDRAM (HM5241605TT, µPD4504161) | Work RAM high |
| IC31, IC32 | 4 Mbit DRAM (HM514260 and equivalents) | Work RAM low |
| IC5 | 315-5688 | SCU, system control unit |
| IC6 | 315-5778 | DCC, DRAM controller |
| IC7 | EPR-17933 or MPR-17933 | IPL ROM (PAL) |
| IC8 | 32K × 8 SRAM (CXK58267AM, µPD43257B and others) | Backup RAM |
| IC9 | 315-5744 | SMPC; the controller ports, reset and the 32.768 kHz clock crystal X4 connect to it |
| IC10 | 315-5689 or 315-5883 | VDP1, sprites and polygons |
| IC11 | 4 Mbit SDRAM | VDP1 sprite (character) RAM |
| IC12, IC13 | 2 Mbit SDRAM | VDP1 frame buffers |
| IC14 | 315-5690, 315-5690-02 or 315-5890 | VDP2, backgrounds |
| IC15, IC16 | 2 Mbit SDRAM | VDP2 video RAM |
| IC17 | 315-5687 | SCSP, sound processor |
| IC18 | MC68EC000FN12 | Sound CPU |
| IC19 | 4 Mbit DRAM (HM514270 and equivalents) | Sound RAM |
| IC20 | 315-5746 | PLL clock generator |
| IC21 | CXA1645M | RGB encoder, to the AV connector CN5 |
| IC22 | TDA1386T | Audio DAC |
| IC33 | 74HC157 | Digital audio multiplexer |
Console5 lists a PCM1717E as an alternative DAC at IC22 on other boards.[5] Sega's mechanical parts list gives the PAL board assembly as 837-11492, "ASSY IC BD SATURN VA0 PAL", while the board in Sega's circuit board diagram is silkscreened "837-11493 IC BD SATURN MAIN VA0 PAL" and "171-6963B"; Console5 gives 837-11491 and 837-11493 for VA0 PAL boards.[4][5]
Later main boards renumber and merge parts. On the VA13 board, for example, IC5 is a 315-5966.[7]
Connections
[edit | edit source]Sega's identifying-parts drawing shows the OPEN button, the cartridge slot, the ACCESS light and control ports 1 and 2 at the front and top, and the POWER jack, the A/V OUT jack and the Master Reset switch at the back.[8] The A/V OUT jack is a 10-pin mini-DIN (CN5) fed by the RGB encoder IC21.[4] Sega's accessories list gives UK and other European machines an RGB cable and Australian machines an RF unit.[4]
Backup battery
[edit | edit source]The backup RAM and the clock run from a CR2032 lithium cell, which Sega's block diagram shows feeding the SMPC (IC9).[6] The parts list gives it as "Battery CR2032/1F" (401-0054) in a Matsushita holder behind a battery lid (253-6915-03).[4][8] A Saturn that loses its saves and asks for the date and time at every start needs a new cell. See Battery Refurbishment.
CD drive
[edit | edit source]The PAL manual lists one drive assembly, 610-5679-20 or -21, and gives Sega's pickup check and adjustment procedure for it.[4] Console5 lists CD-ROM boards from JVC (EXL-P604, EXL-P605, ENR-007 B/D), Hitachi (JA00292) and Sanyo (CDK94V5SGC) across the range, so the drive in one Saturn may differ from another.[5] The procedure is on the Sega Saturn (Model 1) Maintenance Guide.
Documentation
[edit | edit source]- Sega Service Manual - Sega Saturn Pal - 1 June 1995: No. 013-1, Sega's PAL service manual, with the VA0 parts list and the CD drive adjustment.
- Sega Saturn VA13 Service Manual (PAL): the schematic set for the later VA13 board, with two power supply drawings.
- Sega Saturn VA0.5 Schematics: a hobbyist's traced schematic of a VA0.5 board.
Gallery
[edit | edit source]-
A Japanese HST-3200 with the top case off -
Sega's circuit board diagram for the VA0 PAL main board
Related pages
[edit | edit source]- Sega Saturn (Model 1) Maintenance Guide
- Sega Saturn (Model 1) Troubleshooting Guide
- Sega Saturn (Model 1) Capacitor Replacement Guide
- Sega Saturn (Model 2)
- Sega Dreamcast
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 Wikipedia, "Sega Saturn" (secondary source; release dates, launch prices and discontinuation, each cited there to contemporary sources).
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 Sega Enterprises, Service Manual: Sega Saturn (PAL), No. 013-1, June 1995, section 1 "Specifications" (p. 3). See Sega Service Manual - Sega Saturn Pal - 1 June 1995.
- ↑ 3.0 3.1 3.2 3.3 Japanese Wikipedia, "セガサターン" (secondary source), section "バリエーション" (variants): HST-3200 (product HST-0001, 22 November 1994), HST-3210 (HST-0004, from early 1995) and HST-3220 (HST-0014, 22 March 1996), and the overseas equivalents MK-80000 / MK-80000A (North America) and MK-80200-50 / MK-80200A-50 (Europe).
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Sega Enterprises, Service Manual: Sega Saturn (PAL), No. 013-1, June 1995, section 11 "Exploded view and parts list": 11-2 mechanical parts list (p. 71), 11-3 electrical parts list for the main, power indicator, R.SW and SH-1 boards (pp. 72-76) and 11-4 accessories (p. 77). See Sega Service Manual - Sega Saturn Pal - 1 June 1995.
- ↑ 5.0 5.1 5.2 5.3 Console5 TechWiki, "Saturn" (secondary source): IC list for the VA0 main board, capacitor lists by main-board revision (VA0 to VA15), power supply units by maker and model, CD-ROM boards, the VA0 PAL and VA13 PAL schematics, and a repair note on controller-port voltage drops on VA0 to VA0.8 boards.
- ↑ 6.0 6.1 6.2 6.3 Sega Enterprises, Service Manual: Sega Saturn (PAL), No. 013-1, June 1995, section 7 "Block diagram" (pp. 11-12). See Sega Service Manual - Sega Saturn Pal - 1 June 1995.
- ↑ Conjunto P.C.I. VA-13 (Saturn VA13 schematic set, Portuguese title blocks, scanned by Brasilmodchip), main schematic diagram sheet 2/11. See Sega Saturn VA13 Service Manual (PAL).
- ↑ 8.0 8.1 Sega Enterprises, Service Manual: Sega Saturn (PAL), No. 013-1, June 1995, section 2 "Identifying parts" (p. 4) and section 3 "Accessories" (p. 5). See Sega Service Manual - Sega Saturn Pal - 1 June 1995.