Saturn's cart port (the return)

[Dr.Wily]

Maybe the question has been already mentioned. but I'll try anyway.

You know that the STV system uses cartridges, I wonder if it is also possible to boot from Saturn's cart slot ? I ask, because some zone cartridge converters like CD++ display a Sega's screen license before booting. How works these cart ? It's just a "patch" who is modifying the code of Saturn's BIOS or a full custom program (I noticed that a soft reset cancel the effect of adapter) ?

If I ask this, it's about flash cartridges like tototek. A flash cart (or an interface cart) on Saturn could solve many thing like lens issues, modchip installation, zone... However I don't know how certain games will work with this system (game with red book audio or aditinal cartridge).

what do you think?

[alphagamer]

the menu you see when you start up your action replay is a small program loaded into the saturns memory, so why not?

[saturn_worship]

interesting

[TmEE]

The cartslot is bootable and the game I'm going to make for saturn after about a year is going to be a cart game.

[8bitplus]

Would the cartslot be any slower than the cd-rom drive?

[Druid II]

Would the cartslot be any slower than the cd-rom drive?
I'd imagine it would be a good deal faster.

[TmEE]

Unless there's wait states (and I think there aren't any), it will be really fast... CD is way slower in all cases.

[Calpis]

There's gotta be wait states since you don't need 35ns memory. Also since boot memory is 8-bit, there's gotta be a boot loader or the there has to be an 8-bit bus arbiter... Even 4 accesses at 120 ns would be over 5 times faster than the CDROM at its fastest though.

[8bitplus]

"over 5 times faster" very cool.

[Calpis]

ROM is great, but it comes at a very high price. If someone were to produce a new Saturn game of ST-V size (256M) on ROM, you're looking at a $25+ FlashROM and possibly $5 of logic for mapping/the likely necessary bankswitching, not to mention $5+ PCB and $5+ case.

[alphagamer]

ROM is great, but it comes at a very high price. If someone were to produce a new Saturn game of ST-V size (256M) on ROM, you're looking at a $25+ FlashROM and possibly $5 of logic for mapping/the likely necessary bankswitching, not to mention $5+ PCB and $5+ case.

not cheap, but doable!

[Twimfy]

not cheap, but doable!

Considering the average price of a A rated Neo Geo title that isn't bad at all.

[TmEE]

my setup is going to be some 4MBytes of 90ns NOR Flash for boot and crucial data, some MBytes of RAM (possibly DRAM...) and perhaps a 1GB NAND flash chip for data storage.

[Calpis]

Considering the average price of a A rated Neo Geo title that isn't bad at all.
With the PARTS that high, a homebrew title might cost as much as a Neo Geo game.


my setup is going to be some 4MBytes of 90ns NOR Flash for boot and crucial data, some MBytes of RAM (possibly DRAM...) and perhaps a 1GB NAND flash chip for data storage.
Jeez, sounds like overkill if you're going to make more than one of these.

[Shogeki]

I am currently making a daugther board to adapt sop 64mbit memory modules (MX26L6420) on a neo geo pcb (cha512 type).
Ill make a post if you guys are interested, first im just gonna try to run big commercial games, but it would help people that want to develop big games (up to 690mbit)
My point is that making a cart of this size only cost less than 40/50 dollars, making a cart saturn game at low cost seems very possible to me. ;-)

edit: Ok i just re-read Tmee's post and he is gonna use way more recent parts, I'm not quite sure about the price issue for those.

[TmEE]

Jeez, sounds like overkill if you're going to make more than one of these.

I think there will be at least thousand of those made after about 2 or 3 years when my Saturn game is estimated to be finished. Process of learning the workings of Saturn and making a dev environment and tools has not yet begun... it will in next year, when my MD game is finished and being sold on cart.

[Calpis]

I am currently making a daugther board to adapt sop 64mbit memory modules (MX26L6420) on a neo geo pcb (cha512 type).
Ill make a post if you guys are interested, first im just gonna try to run big commercial games,
<OT>So people can sacrifice cheap games to build their own bootlegs of expensive games? :banghead: The SNK ASICs aren't even complicated...

Also you know you can do this much cheaper using two 256M flashes and jumpering the high address lines normally decoded? That would mean only one PCB per "repro"/boot instead of 8.


I think there will be at least thousand of those made after about 2 or 3 years when my Saturn game is estimated to be finished.
A thousand? Wishful thinking when R&D hasn't begun? Also planning a multimedia game or just planning to blow away commercial Saturn games? ;-)

Looking at average prices on Digikey for 1000 pcs:
32M TSOP flash = $6
32M BGA PSRAM = $6
16M BGA PSRAM = $4
16M BGA SRAM = $16
16M TSOP SRAM = $29!
16M TSOP DRAM = $6 but need address MUX
Logic = $2 for address decoder PLD, $5+ for CPLD for NAND or MCU interface and DRAM MUX

PCB = $5+
case = $5+

When all is said and done, even if you self-publish, unless the game warrants $60+ I can't see you making any sort of profit.

[TmEE]

The 1000 came from almost nowhere... but if you can sell same amount carts for MD, it should not be too hard for Saturn...

It is going to blow commercial games away, or at least get close to :) I am seriously looking forward to messing with Saturn. MD is fun, Saturn is more fun :) I am pretty confident in my ASM skills... still, there's going to be a 1 year learning and tool development period...
Only the boot ROM has to be of NOR flash (which is a bit expensive), data storage is all in a NAND flash and those cost nothing... If needed, I could use an SD card for data storage if there's no nice chips around :P
RAM is not mandatory, but it can be handy if there's something present...

and there's no profit involved, its made for fun to say so, more or less like Pier Solar for MD is being made (and I am helping to make that game BTW).

I will be building a proto cart which gets used a the base for my whole Saturn dev, much like things are right now with my MD ventures...

[Shogeki]

<OT>So people can sacrifice cheap games to build their own bootlegs of expensive games? :banghead: The SNK ASICs aren't even complicated...

Also you know you can do this much cheaper using two 256M flashes and jumpering the high address lines normally decoded? That would mean only one PCB per "repro"/boot instead of 8.


I saw some bootelgs using customs pcbs but a lot of them were actually using snk pcbs as well. (including some cart using 16 27c322 piggy backed, the whole things was so heavy).

I would like to take a look at those 100 in 1 carts to see what kind of memory is used, but your idea of using bigger memories sounds good since it would be only 2 roms to reprogram everytime.

But then again, a homebrew game like last hope is 188M, but still not as good as last resort (45M) (for gameplay reason but also graphically because of the use of some of the horrible cgi used ).

But I'm sure a larger team of developper would be able to use well the full ~700M availble.

[Calpis]

But I'm sure a larger team of developper would be able to use well the full ~700M availble.
Well technically the NG can address 1Gbit CHA directly out of the box, though obviously no games come close. By my count using the bankswitching schemes already in place, games could go up to 1228/1229M depending on whether the fixed layer ROM is discrete.

[MottZilla]

Well technically the NG can address 1Gbit CHA directly out of the box, though obviously no games come close. By my count using the bankswitching schemes already in place, games could go up to 1228/1229M depending on whether the fixed layer ROM is discrete.

So 64 Mbytes (8 x 8Mbyte CHR) that the biggest NeoGeo game had wasn't actually the limit? I thought that they had basically hit the limit.

[l_oliveira]

So 64 Mbytes (8 x 8Mbyte CHR) that the biggest NeoGeo game had wasn't actually the limit? I thought that they had basically hit the limit.

Don't that amount exactly to 16 27C322 eproms ?
That's what I have seen on Neo Geo botlegs... That or Macronix 26L6420 EEPROMs ripped from scrapped pachinko machines (the chinese botleggers even leave the pachinko machine stickers on the chips !!!!!!)

So you see ... For the chinese to make all these botlegs it does not cost them anything but the scrap they buy...

[Shogeki]

yeah, i found a preshistoric isle bootleg recently that is using a real bout 2 pcb, with 16 27c322 piggy backed (and the encrypted romset programmed on them on it since it used a chafio board).
A hex inverter is also used.
Ive seen some half artisanal cps2 bootlegs using 26L6420 too, mostly sf2 hyper fighting and progear arashi.
Thanx for the infos calpis, i would love to see some homebrew games using the full potetial of the neo geo.

[Jamtex]

No homebrew game is ever going to use the full potential of a machine and if they do, it's likely to be a crap game. There are a lot of technically great Atari 2600 games but most of them are a borefest.

[Taucias]

You could say that for almost all Atari 2600 games though, the later comment anyway...

[alecjahn]

Don't stop the momentum, this thread is awesome.

As amazing and unique it'd be to have a cartridge-booted homebrew SS game... actually, I guess a disc wouldn't be much easier, with the holographicy copy protection ring...

How about crack the cart slot, put instructions for your own flash carts?

[TmEE]

I need to get more richer and buy some RAM carts to see how they work... I have a PAR which I need to reverse engineer a little to know what it does so its booted...
I've heard Saturn cartslot is a POS so if at least RAM expansion and external save space is added to the cart makes need to change carts less frequent and thus help preserving the cartslot to some extent....

[Mr. Sound-About]

No homebrew game is ever going to use the full potential of a machine and if they do, it's likely to be a crap game.

Wait for the release of Zaku (http://www.zaku-lynx.com/) and I think you'll be quite pleasantly surprised at how wrong you are. :)