Dreamcast hardware list based on internals

[Warning: work in progress... will add images/other stuff the next few days]

Over the years, a lot of people have discussed the different dreamcast models.
A lot of lists based on the external hull exist, but few reliable lists based on the internal hardware differences exist.
This list tries to regroup that information based on reliable sources only (ie, Dreamcast I have or detailed photos).

I’ve collected +- 30 dreamcasts, mainly Japanese for the moment, and made a small program to do a few BIOS/… checks.
It is a continuous work-in-progress, so it 1) is not complete (especially the production years) and 2) will be adapted in the next days/weeks/months/....

If you have Dreamcast models not mentioned here, or models that contradict / complete the info here, please:
- Post internal & external pictures of your model
- Specify it is first-hand or second-hand
- (to be added later: Run the checker program)

1) DREAMCAST
===========

having trouble with inserting tables at the moment... Is there a correct way to do this ?
I'll put it on my site for the moment: link here)

 

One you can add based on the DC in front of me:

670-14081G - SD - 2000

I'm guessing based on your information that it is a NTSC-U (1) model. Plastic fan, has its own GD-ROM daughterboard, "Compatible with Windows CE" and is made for "SEGA Enterprises,LTD".

 

Thanks for the info, I've added it & changed some formatting/...
In which country was it made ?

As you can see, I miss a lot of info on the US Dreamcasts, so any info is welcome.

If you can make pictures of the back label, that would be fantastic too.

 

What do you want pictures of internally, all individual boards? Or just with the top cover off?

I have a number of PAL DCs that I can interrogate.

Also, do you want the production date that's stamped into the bottom cover, under the motherboard? Any other data from there? There is a list (A:330, B: 250, C: F1350, etc.) in the one I have in front of me, any of it relevant?

Any other info? As I recall, there were a few different revisions of GD-ROM unit. Is that something you're compiling info on?

 

I've received a few similar questions, so I specified what would be good info at this stage to complete the list: cfr "How to participate".

Not necessary at this stage.
First, I'd like to have a complete & reliable list of the 670-xxxxxx model nrs with the info I've already put in the list (fan, wince logo, ...).
That should allow the average DC collector / buyer to know & choose what he buys.
The day we have this list, we might go further & look at the motherboard nrs & stuff like that.

 

Made in Japan.

One picture hot off the presses:



Sorry about the fuzziness on the right side. Can't seem to get my camera to not do that.

 

OK, here's pictures of mine, which is not completely detailed in the table.

Region: Europe
HKT nr. : HKT-3030Color Encoding: (1) PAL-E
Fan: Metal
Windows CE: Compatible With
Company: Sega Enterprises Ltd.
MIL-CD: Compatible
GD-ROM daughter board: NoModel nr.: 670-14088C

Do not have BBA or other connectors, so cannot do ELF test.

 

Data updated, thanks to both of you !

After seeing this, I realized it wasn't trivial for everybody to make the distinction.
I've added two pictures to help people decide if there is a daughterboard or not: http://users.skynet.be/t_chan/dc/mylist.htm#diff_gd_daugher_board
I've put "Yes" in my list for 670-14088C.

Could you take a close-up picture of the fan ?
It's quite different from the jap metal fan, so I'd like to add it to the fan comparison photos.

I've also added a row with the GD-ROM manufacturer, so the new template is:
Region: Japan/Asia/USA/Europe
HKT nr. : HKT-3000 / HKT-3010 / HKT-3020 / HKT-3030
Color Encoding: NTSC-J / NTSC-U (with the number in the circle) / PAL (with the letter & digit besides it, eg PAL-E (1))
Fan: Metal / Plastic
Windows CE: Designed For / Compatible With
Company: Sega Enterprises / Sega Corporation
MIL-CD: Compatible / Not Compatible
GD-ROM Manufacturer: Yamaha / Samsung
GD-ROM daughter board: Yes / No
Model nr.: The 670-xxxxxx nr, with the last x being a letter

 

I wasn't familiar with the non-daughterboard type, do you have any other pictures, or linked to on the net? I couldn't find any. Going by your data, it looks like a later "improvement" - are the motherboards significantly different to accommodate this?

Certainly, none of my PAL DCs are like that. It looks like the wires from the spindle apparatus (?) are connected directly to the motherboard?

I must dig out the coders cable and see if it still works, it's been ages since I had it out. Don't suppose you have a link to a good tutorial to refresh myself on how to use it?

 

Indeed, the cables of the GD Motor & Laser are directly connected to the motherboard, instead of to the GD-Rom daughterboard.

Here's another picture:

It's quite easy. In short:
1) launch your DC with dcload-ip
2) Launch a DOS command on your PC:
dc-tool.exe -t the_dc_ip_address -x release.elf

eg. dc-tool.exe -t 192.168.0.4 -x release.elf

 

Will try and do that tomorrow for you - I'll even try and use a better camera next time!

As for GD-ROM manufacturer, where would that be found? Stamped on the metal shielding beneath the drive?

 

I guess he needs dcload-serial (click) and use dc-tool.exe -x <filename> to upload and execute files.

 

Indeed, on the metal shielding under the drive, near the fan.

 

Great idea, I have wanted to see something like this for years :thumbsup: I have some advice though if you dont mind...

Firstly, I strongly recommend you start collecting console serial numbers as well, since the serial number can be broken down to give the week/year of production and the factory and lot number. You could also record the 'date clocks' which are molded into the casing and give the week and year the case was manufactured.

Also, you can break down the Yamaha and Samsung drive types even further, since there are different GD-drive sub-boards. Launch console GD-drives use a drive board with an OTI 9220 chip, whereas later drive boards have the code 'XV779' and use three chips made by either Yamaha or Toshiba, although sometimes they will be rebranded with a Sega name/part number. It might also be a good idea to record if the drive uses a Samsung or Yamaha laser, since there seems to be some mix-and-match parts between drives:-
http://www.assemblergames.com/forums/showthread.php?t=20285

Also, there are multiple revisions of the modem which use the same Rockwell/Conexant chips but are completely different, so it would be better to record the board name/part number rather than the chip, for instance I have seen these board names:-
IC BD MODEMARU JPN (SEGA 1998) 33k
IC BD MODEMARU USA (SEGA 1999) 56k
IC BD MODEMARU JPN/USA (SEGA 2000) 56k
IC BD MODEMARU EUR/AUS (SEGA 1999) 33k
There are also PCB part numbers such as '837-13171' but I have not identified which ones match which modem revisions. The number you are currently recording (e.g. 670-14140A) only identifies Sega's sticker part number, the 'A' or 'B' at the end denotes that the text on the sticker changed not that the modem board inside changed. Oh and there was no European 56k modem, so i'm not sure how one got on your list? Presumably it was imported.

Also, if you know the BIOS revision then there is no need to ask if its MIL-CD compatible, as MIL-CD compatibility is simply a matter of which BIOS revision is used.

There is probably even more info that I have forgotten, but its certainly an interesting area to look into. Good luck with the list :nod:

 

I agree with link83, aim to get as much comprehensive info as possible in one swoop, whilst contributers have their DCs out and open. They might be less inclined to go back later if they have to pull a few units out of storage just to pull a number off a power supply board, for example.

I know myself, I wouldn't mind spending a couple of hours some rainy afternoon pulling numbers off my 6 or 7 DCs for your project. The info is very much worth documenting.

 

Lots of remarks, I'll try to answer them all.

First of all, bare with me:
- I'm far from having transposed all my notes & pictures. Making it public so "raw" forces me a little bit to structure & document it properly, while getting feedback.
- Unless there's a typo, all data in the list have been verified by me (ie, only seeing it in reality or seeing clear pictures of it.). No rumors from the net have been used. You'll see the pictures to prove what's in the list, but updates & formatting take time.

I don't mind at all, any remarks are welcome. ;-)

Concerning what to ask to people to document: Both of you have a point, but I also want to propose a short version to the average guy who doesn't want to disassemble the Dreamcast entirely. I'll think about a profile-based documentation request (eg. "amateur" vs "pro").

I'll add a "min & max serial nr found" for the dreamcasts. (I already did have the info, but didn't transpose it to html)

I know about the manufacturer & year for japanese serials, and the year for US/EUR dreamcasts, but where can you find the week in the serials, or the manufacturer in US/EUR DC serials ? Same question for the lot number.

Week ? I suppose you mean 'month' ?
The big questions is how reliable this info will be, since the top hull is one of the easiest thing to swap with another DC...
But the date clocks on the hull are indeed interesting, I'll probably add a "min-max date found".

[Modems]
The problem with the different modem model/board/part numbers, is that there is no 100% correct way to identify some hardware just by looking at one number.
eg: 837-13771, IC BD MODEMARU EUR/AUS, 171-7955D is used for both the boards with a Rockwell 97 RP336LD R6785-17 chip, and those with a Connexant RP336LD R6785-18 chip. Here the 670-14116A / 670-14117A can sometimes tell the difference.

But yes, here, the more info, the better for the modems, since its limited anyways & since it's quite easily accessible (2 screws only).

I suppose you mean "_I don't think_ that that it exists". ;-)

Have a look at the updated modem chapter, you'll see pictures of a 56K EUR/AUS modem. ;-)
Was it sold and where, or was it a prototype ? No idea, but I've found one in a lot of 15 "junk" modems I bought a while ago. Unfortunately, the outside sticker is washed out, so no way to tell what was written on that.
(Again, I've only put & will only put things in the list that I can proove.)

Has this been proven by somebody dumping the bios of the non-MIL-CD compatible Dreamcasts ?
If not, I can imagine there are other ways to block the MIL-CDs by eg adapting the GD sub-board, but leaving the BIOS untouched.
Once my checker program is polished enough, I'll burn it on a GD-R & test it on those Dreamcasts.
(data-data CD's didn't work with those DC's for me, so I still haven't been able to verify if the data-data / adapted BIOS info was an urban legend or not)

Thanks and if you have Dreamcasts, feel free to post pictures ;-)

 

You can gather a lot of info without opening the system, the base stickers can give quite a bit of info, plus you can tell which type of laser is used by opening the drive lid, and if you can run hombrew you can identify the BIOS revision as well, all without opening the system.

You might also want to document Dreamcast accessory revisions? For instance the Dreamcast controller was manufactured in different countries/factories using different parts. The D-pad height was changed on later controllers, and they also have a more purple colored cable rather than the grey cable used on early models.

Thats useful, but it doesnt tell you as much. I compiled a serial list/revision guide for the N64:-
http://forums.benheck.com/viewtopic.php?f=5&t=27684
Obviously the N64 is much simpler to document compared to the multiple manufacturers and parts used on the Dreamcast, but you can see patterns in the serial numbers and production. I wanted to do exactly what your doing for the Dreamcast, but I just haven't got enough free time.

I worked this out for European Dreamcast serials years ago, but I cant find the details now :redface: Obviously the year is the third digit, the first two digits should be the factory like Japanese Dreamcasts, and there was also a lot number (Not week number, sorry) You may want to compare the serial numbers with the known Mega Drive serials:-
http://www.sega-16.com/forum/showthread.php?15874
and Sega Saturn serials:-
http://www.geocities.jp/atx197/SS_RESEARCH_02.pdf
Both of which use a similar serial layout. If you start compiling serial numbers and comparing them it should be possible to see patterns in the numbers ;-)

Yeah sorry, I meant month/year.

I'm not sure what you mean by 'hull'? (Perhaps the meaning is lost in translation?) I think 'casing', 'case' or 'shell' might be a better terms to use.

Thats just because Rockwell and Conexant are basically the same company and the chips are pin compatible and used interchangeably:-
http://www.conexant.com/company/about.html
"Conexant is a fabless semiconductor company that spun-off from Rockwell in 1999"

Yes the more info the better, so if you want to record the chip brands then theres no harm in doing so, I just think the PCB revision is more important.

Its very interesting to see an RP56LD chip in a EUR/AUS modem (Could it be Australian?) but it doesn't prove definitively that its a 56k modem. From what I have read in the datasheet the RP336LD and RP56LD chips are pin compatible, and it could be that Sega was just using up surplus RP56LD chips and that they were set to 33k speeds, especially since they both use the exact same PCB revision. Have you tested if this modem can actually run at 56k speeds?

Here is a list of BIOS revisions I have seen using Sega's chip numbering scheme:-
MPR-21068
MPR-21086-X2
MPR-21871
MPR-21931-X1
MPR-21931-X2
MPR-21933
MPR-21933-X2
MPR-23588
MPR-23588-X2 (JPN Sakura Wars Model)
Some more info about BIOS revisions here:-
http://dumpcast.thekickback.com/forum/viewtopic.php?t=499
From what I have read MIL-CD support was removed from MPR-21933 onwards, and I also read that people actually resorted to removing BIOS chips from old Dreamcast's to place into the newer ones to re-add MIL-CD support. Obviously this is anecdotal evidence, but i'm sure someone can confirm this for sure.

I'm not sure what you mean by "I still haven't been able to verify if the data-data / adapted BIOS info was an urban legend or not"?

I really wish I could as I bought a few broken Dreamcast's some years ago but I ended up mixing and matching parts to get them all working, so I dont think I can help. I really wish I had recorded all the details :crying:

 

The Modems/LAN/BBA part has been updated into this document:
http://users.skynet.be/t_chan/dc/dc_modems.xhtml
Feel free to check it / post your comments if you have models that don't match those of the list.

If someone has a USA Broadband adapter, can you check if it matches the PCB numbers of the JAP version ?

That was my point for asking a limited list of properties, I guess I wasn't clear enough.

No I haven't, since I haven't an easy way to test it.
Since other 56k modems sometimes use the same PCB revision as some 33k modems (cfr USA C3 vs JAP B), in the benefit of the doubt, I'll leave the EUR/AUS 56k modem marked as 56k, until proven otherwise.

Interesting link, but we have another definition of 'BIOS revision'.
For me, a 'BIOS revision' is the content (software) of the BIOS, not the rom-chip on which it was burned.
I suppose they could have burned different BIOS revisions on the same chip nr on different motherboards, so for me here the content of the chip is more important than the marking.
We might find a correlation between the marking & the content once we start inventorizing the motherboards though.

-> I want to check the content (CRC) of the two non-MilCD compatible Dreamcasts I have to see if the BIOS is really different from the 1.01d version, but for the moment I can't:
- I can't upload a program to them since the cd with dcload-ip is not recognized,
- cd's with data-data in the first session instead of audio-data doesn't work, contrary to what people believe of the non-milcd compatible Dreamcasts.
And as far as I know, nobody has ever done a CRC on the BIOS of these Dreamcasts.
So I'm afraid I'll have to sacrifice a GD-R to check that.

Well, at least you should be able to help for the modems then

 

Thats really great, you have obviously put a lot of work in :thumbsup:

Sorry, I worded that sentence badly but I was just trying to give some suggestions as to the sort of things you could ask.

Hmm, well i'm not certain but it appears that Sega used the 837-XXXXX silkscreen numbers to show which chips/part numbers could be used on any given PCB revision, this is corroborated by chessage's findings at Sega-16 forums:-
http://www.sega-16.com/forum/showth...ve-Genesis-Main-ASIC-List&p=355756#post355756

Since the USA C3 and JAP B both have two numbers next to each other (837-14040 and 837-14041) It implies that the 'IC BD MODEMARU JPN/USA' PCB was designed so that one of two different chips could be used, probably referring to the RP336LD and RP56LD. this seems even more likely when you notice that the modem that uses the RP336LD (JAP B) has at least four less capacitors (C5, C14, C23 and C27) than the exact same PCB revisions which use the RP56LD (USA C3 and JAP C) Likely because the RP56LD needs these capacitors but the RP336LD doesn't. There also appears to be at least one point labelled 'JP1' suggesting these might be jumpers used to determine which chip is used?

Since the 'IC BD MODEMARU EUR/AUS' PCB doesnt have multiple 837-XXXXX numbers silkscreened on the board it seems likely to me that it was only designed with one chip in mind, that being the RP336LD. Obviously your pictures prove that Sega also used the RP56LD on this PCB revision, but I think its probably still fixed to 33.6k speeds since the PCB was not designed for the RP56LD.

...This is just a guess/theory and i'm not saying you should change your guide, but I just thought I would point out a few things I noticed.

You are correct, but from what I have read the MPR part number/BIOS revision correlation was confirmed a long time ago as the Mega-CD and Sega Saturn use the same MPR chip naming scheme. The MPR-XXXXX number is Sega's way of recognising which particular BIOS revision is on the Mask ROM/EPROM, so each different MPR number should contain a different BIOS revision (You can ignore the 'X1' and 'X2' numbers, its the main number thats important)

Interesting, do your data-data disks work on a standard Dreamcast? Also is this a very late model? I only ask as I wonder if Sega could have revised the BIOS one last time after the data-data format started being used.

I'll see what I can dig out ;-) (They are all European though, so I think the only difference is some use Rockwell chips and some use Conexant)

 

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