Sega Saturn (Model 1): Difference between revisions

| image        = [[File:Sega Saturn VA0 PAL main board parts location.png|260px]]

| caption      = Sega's circuit board diagram for the VA0 PAL main board

| manufacturer = Sega Enterprises, Ltd.

| release date = 22 November 1994 (Japan)<br />11 May 1995 (North America)<br />8 July 1995 (Europe)<ref name="srsat">[https://segaretro.org/Sega_Saturn Sega Saturn], Sega Retro. '''Secondary source.''' Release dates, recommended retail prices and Sega model codes, each footnoted on that page to a contemporary source: Japan 22 November 1994 at ¥44,800 (HST-0001), North America 11 May 1995 at US$399.99 (MK-80001), Western Europe 8 July 1995, United Kingdom 8 July 1995 at £399.99 (MK-80208-05), Germany, Spain and France 7 July 1995. Also the source for the two case designs — the HST-3200, later revised as the HST-3210, sold from the Japanese launch until early 1996 with blue oval buttons and both Power and Access LEDs, and the HST-3220 announced at Sega Saturn Power Up Meeting '96 Spring and released on 22 March 1996, whose only functional change is the omission of the Access LED — and for the statement that overseas machines are physically identical to the Japanese ones save for region encoding and black plastic.</ref>

| discontinued = 1998 (Europe and North America)<ref name="srsat" />

| price        = ¥44,800 (Japan) • US$399.99 • £399.99<ref name="srsat" />

| cpu          = Two 32-bit RISC SH2, 28.4&nbsp;MHz, 25&nbsp;MIPS each; 68EC000 at 11.3&nbsp;MHz for sound<ref name="satman">Sega Enterprises, Ltd., ''Service Manual — Sega Saturn (PAL), No. 013-1'', June 1995 — hosted on this wiki as [[:File:Sega service manual - sega saturn pal - no. 013-1 june 1995.pdf]] (see [[Sega Service Manual - Sega Saturn Pal - 1 June 1995]]). Section 1 gives the ratings and specification (model MK-80200-50, AC 220–240 V 50/60 Hz, approximately 20 W, 5–35 °C and 10–80% RH non-condensing, 260 × 230 × 83 mm, master and slave 32-bit RISC SH2 at 28.4 MHz and 25 MIPS, 68EC000 at 11.3 MHz for sound, 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, 320 × 224 dot, 1024/2048 colours from 16,770,000, five screens maximum, 32 sound channels with PCM and FM and a 16-bit 44.1 kHz maximum sampling rate, and an intelligent double-speed CD drive); section 3 the accessories (lithium battery CR2032, RGB cable, and AC cables for the UK, SOE and Australia); section 4 the board identifications; section 5 the disassembly; section 6 the CD drive maintenance and adjustment figures; section 7 the block diagram with the power supply rails; section 9 the circuit board diagrams and section 11-3 the electrical parts list for the VA0 main board.</ref>

| memory      = Work RAM 16&nbsp;Mbit • video RAM 12&nbsp;Mbit • sound RAM 4&nbsp;Mbit • CD buffer 4&nbsp;Mbit • IPL ROM 4&nbsp;Mbit • backup RAM 256&nbsp;kbit<ref name="satman" />

| storage      = Intelligent double-speed CD-ROM drive; backup RAM, expandable by cartridge<ref name="satman" />

| display      = 320 × 224 dot and other modes; 1024/2048 colours from 16,770,000<ref name="satman" />

| sound        = 32 channels, PCM and FM, 16-bit sampling at up to 44.1&nbsp;kHz, audio DSP<ref name="satman" />

| dimensions  = 260 × 230 × 83&nbsp;mm<ref name="satman" />

| os          = IPL ROM, 4&nbsp;Mbit (EPR-17933 / MPR-17933 on PAL machines)<ref name="satman" />

| model        = MK-80200-50 (PAL) • MK-80001 (North America) • MK-80208-05 (UK) • HST-3200 / HST-3210 (Japan)<ref name="satman" /><ref name="srsat" />

The '''Sega Saturn''' is Sega's CD-based successor to the Mega Drive, released in Japan in November 1994 and in the West the following summer. "Model 1" on this wiki means the first case design — the '''HST-3200''', later revised as the HST-3210, with blue oval buttons and both Power and Access indicators, sold until the white HST-3220 arrived in March 1996.<ref name="srsat" />

'''The Saturn is mains-powered.''' The PAL machine is model MK-80200-50, rated AC 220–240 V at 50/60 Hz, drawing approximately 20 W, and it takes a detachable mains lead — Sega's accessories list gives three, for the UK, for SOE territories and for Australia.<ref name="satman" /> There is no DC adaptor, no barrel jack and no external power brick. Any guide that tells you to check for 9 or 10 V at a power input is not describing this console.

Sega's own ratings and specification tables.<ref name="satman" />

 

The service manual's block diagram gives a master clock of 28.6 MHz and a 14.318 MHz reference into the PLL, against the 28.4 MHz quoted in the specification table; the two figures are for the same part and the difference is a rounding convention rather than two different machines.<ref name="satman" /><ref name="satva13">''Sega Saturn VA13 Service Manual (PAL)'' — hosted on this wiki as [[:File:Sega Saturn VA13 Service Manual PAL.pdf]] (see [[Sega Saturn VA13 Service Manual (PAL)]]). A partial scan, redrawn and watermarked by a third party: an overall block diagram giving the 28.6 MHz 32-bit clock and the 14.318 MHz PLL reference, eleven main-board schematic sheets and power supply and CD unit sheets. It carries no parts list. Sheet 1/11 shows IC1 and IC2 as the two Hitachi SH-2 devices (IC2 marked 315-0998) with IC3 and IC4 as 4 Mbit SDRAMs on a separate LVCC supply; sheet 2/11 shows IC5 as a Yamaha 315-5966, a different part from the VA0 board's IC5.</ref>

== Rails ==

From Sega's block diagram, measured at the main board's power connector.<ref name="satman" />

{| class="wikitable styled-table" style="width:70%;"

|-

| +9 V || CD drive, and the PLL

|-

'''There is no +12 V rail on a Saturn''', and no negative rail. The supply is a bought-in switching module mounted inside the case, and its manufacturer varies by machine and market.<ref name="satman" /><ref name="c5sat">console5 TechWiki, ''Saturn'', https://wiki.console5.com/wiki/Sega_Saturn . Secondary source — per-revision capacitor lists read off real boards, covering VA0 through VA15, the power supply units by manufacturer and model, and the CD-ROM PCBs. Its VA0 PAL list (837-11491 / 837-11493) agrees position for position with the parts list in Sega's own PAL service manual, including the values at CE30 and CE54 that are specific to PAL boards.</ref>

On VA0 PAL boards the position silkscreened '''FUSE''' is filled with a jumper wire, Sega part 600-6458, "JUMPER WIRE L=10MM".<ref name="satman" /> There is nothing to test there.

== Boards ==

 

 

The bare PAL main board numbers for the earliest machines are 837-11491 and 837-11493.<ref name="c5sat" />

 

 

From Sega's electrical parts list.<ref name="satman" />

{| class="wikitable styled-table" style="width:88%;"

|-

| IC7 || EPR-17933 / MPR-17933 || IPL ROM — the PAL part; NTSC machines carry a different ROM

| IC25 || S-80741AL || Voltage detector

|-

| IC31, IC32 || 4 Mbit DRAM || CD buffer RAM

 

Sega's identifying-parts drawing gives the console's external connections as the '''power jack''' (the mains inlet for the detachable lead), the '''AV OUT jack''', two '''control ports''', the '''cartridge slot''', the '''OPEN''' button, the '''ACCESS''' light and the '''Master Reset''' switch.<ref name="satman" />

 

 

 

Saves and the clock are held up by a '''CR2032''' cell; Sega's accessories list gives it as "Lithium Battery (CR2032)" with the note "Positive Side B".<ref name="satman" /> A machine that forgets its saves and its clock wants a cell, not a board repair.

 

 

Several different CD-ROM boards were fitted across the range — JVC EXL-P604, EXL-P605 and ENR-007 B/D, Hitachi JA00292 and Sanyo CDK94V5SGC — so a drive from one Saturn is not necessarily the same assembly as the drive in another.<ref name="c5sat" />

Sega's maintenance figures, and its warning about the one adjustment people reach for first, are on [[Sega Saturn (Model 1) Maintenance Guide]].

== Documentation ==

 

* [[Sega Service Manual - Sega Saturn Pal - 1 June 1995]] — No. 013-1, June 1995, the PAL service manual with the VA0 parts list.

* [[Sega Saturn VA13 Service Manual (PAL)]] — a partial scan of the later VA13 board's schematics, with no parts list.

 

 

* [[Sega Saturn (Model 1) Maintenance Guide]]