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View topic - Play SMS roms on a real SMS system (again)

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MrVCD
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Play SMS roms on a real SMS system (again)
Post Posted: Fri Oct 22, 1999 3:53 pm
I never really got my question answered but to all you electronics majors/die hard game hobbyists out there. Is there any way to play SMS roms on a real SMS system? I am not a fan of emulation (I own copier devices for many console systems except SMS) and I want to play SMS roms on a real sms. Perhaps some sort of blank cartridge? That would be cool for people who have a Mastergear and Gamegear...

Any suggestions? Anyone wanna try something? A disk drive interface of some sort would be nice.
 
Nyef
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Post Posted: Fri Oct 22, 1999 6:55 pm
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> I never really got my question answered but to all you electronics majors/die hard game hobbyists out there. Is there any way to play SMS roms on a real SMS system? I am not a fan of emulation (I own copier devices for many console systems except SMS) and I want to play SMS roms on a real sms. Perhaps some sort of blank cartridge? That would be cool for people who have a Mastergear and Gamegear...

The last time you asked this question, we went from the basic outline for the design of a blank cart to thinking about how to add a disk drive in about 4 messages. We then discussed the Saturn for a while.

The answer to the question you were asking then (and now) was given within the first few posts.

The time before, we came up with ideas for adding vectored interrupts, standard IDE hard drives, keyboards, internet access, and web browsing to a stock SMS.

Therefore, since both previous threads answered the question you asked, I must assume that you are not asking the question that you really want answered.

Given that you are addressing your question to "electronics majors" and "die hard game hobbyists" and that you own "coper devices for many console systems", I can only assume that what you really want is for someone to design and build the device for you because you don't want to have to figure out how to make one yourself. Am I right?

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> Any suggestions? Anyone wanna try something? A disk drive interface of some sort would be nice.

--Nyef
 
Michael Montague
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Post Posted: Fri Oct 22, 1999 7:43 pm
[Snip]

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> Given that you are addressing your question to "electronics majors" and "die hard game hobbyists" and that you own "coper devices for many console systems", I can only assume that what you really want is for someone to design and build the device for you because you don't want to have to figure out how to make one yourself. Am I right?

I think I missed some of these posts ... I know very little about electronics, but know enough to build cartiridge copies and such ...

Are there any ideas for how to build a device like that? (A blank ROM that is.) If someone can come up with some ideas on plans I'll build one and write software for it.

Also, in a related note, any ideas on using the user port of an SMS for debugging information? This would be sooo useful for budding SMS programmers and emu developers. :)

- Mike
 
Nyef
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Post Posted: Fri Oct 22, 1999 8:07 pm
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> [Snip]

> > Given that you are addressing your question to "electronics majors" and "die hard game hobbyists" and that you own "coper devices for many console systems", I can only assume that what you really want is for someone to design and build the device for you because you don't want to have to figure out how to make one yourself. Am I right?

> I think I missed some of these posts ... I know very little about electronics, but know enough to build cartiridge copies and such ...

Some of them are still on the board. Just scroll the index page down a bit. :-)

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> Are there any ideas for how to build a device like that? (A blank ROM that is.) If someone can come up with some ideas on plans I'll build one and write software for it.

http://smspower.speedhost.com/dev/forum/messages/628.html is the basic outline I alluded to earlier.

It wouldn't really be hard to write the software at all. The trick is actually converting the ideas presented to a usable device. I could possibly specify the chips to use more accurately, but I suck at actually building the damned things, so I don't bother. :-)

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> Also, in a related note, any ideas on using the user port of an SMS for debugging information? This would be sooo useful for budding SMS programmers and emu developers. :)

For debug info? Well, you could map a dumb serial port or a UART into the CPU I/O space and write code that dumps debug messages out over it... That's all I can really think of right now.

I also don't see how it would be of use to emulator authors. But that's probably just me. :-)

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> - Mike

--Nyef
 
Michael Montague
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Post Posted: Fri Oct 22, 1999 8:16 pm
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> It wouldn't really be hard to write the software at all. The trick is actually converting the ideas presented to a usable device. I could possibly specify the chips to use more accurately, but I suck at actually building the damned things, so I don't bother. :-)

I would definatly like to attempt to build one of these things, but I don't know how to wire all the parts together with out a schematic. Do we have any EE guys around? :)

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> For debug info? Well, you could map a dumb serial port or a UART into the CPU I/O space and write code that dumps debug messages out over it... That's all I can really think of right now.

> I also don't see how it would be of use to emulator authors. But that's probably just me. :-)

I'd love to be able to see the status of the various registers in the Z80 and the VDP. Imagine being able to watch the processor and such while the actual hardware was running. Was there ever a Pro Action Replay for the SMS?

- Mike
 
Eric
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Post Posted: Fri Oct 22, 1999 8:44 pm
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> > It wouldn't really be hard to write the software at all. The trick is actually converting the ideas presented to a usable device. I could possibly specify the chips to use more accurately, but I suck at actually building the damned things, so I don't bother. :-)

> I would definatly like to attempt to build one of these things, but I don't know how to wire all the parts together with out a schematic. Do we have any EE guys around? :)

Regarding building a SMS "RAM" cart:

Dallas Semiconductor (www.dalsemi.com) has an interesting memory device they call NV-SRAM. It's a RAM chip that includes on on-board battery that is automatically enabled once power (Vcc, specifically) is removed from the chip, thus allow the cartridge to store data indefinitely (the manufactures claim the batter lasts up to 10 years). Additionally, there are sizes up 16 Megabit (i.e., FOUR times the size required by standard SMS games.)
The difficulty is creating the paging logic. I believe it could easily be done with a PAL, but I lack the tools to create my own custom PAL chips. Since the whole design fits on two chips, a board could be created that would easily fit into a standard SMS cartridge case.

Again, I lack the tools necessary to complete such a project, but would be happy to help out. I have experience building a (working) SMS cartridge copier.

Quote
> > For debug info? Well, you could map a dumb serial port or a UART into the CPU I/O space and write code that dumps debug messages out over it... That's all I can really think of right now.

> > I also don't see how it would be of use to emulator authors. But that's probably just me. :-)

> I'd love to be able to see the status of the various registers in the Z80 and the VDP. Imagine being able to watch the processor and such while the actual hardware was running. Was there ever a Pro Action Replay for the SMS?

The Z80 has no innate debugging capabilities, making it difficult to create useful in-circuit debugging tools for the SMS.

Additionally, there's no way to view the Z80 registers. Because they are registers, any data transfers to/from them occur internally, no register transactions appear on the bus. I imagine the same is true for the VDP.

Nyef's idea of creating a debugging port has serious potential, however, it's only useful in developing new programs, and not reverse-engineering existing SMS software.

Again, I'd be happy to help out any one interested in creating a SMS bus device, I do have experience creating hardware of this type. Currently, though, I'm not willing to start such a project myself. I'm still working on my emulator.

Eric Quinn
 
Nyef
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Post Posted: Mon Oct 25, 1999 5:56 pm
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> > > It wouldn't really be hard to write the software at all. The trick is actually converting the ideas presented to a usable device. I could possibly specify the chips to use more accurately, but I suck at actually building the damned things, so I don't bother. :-)

> > I would definatly like to attempt to build one of these things, but I don't know how to wire all the parts together with out a schematic. Do we have any EE guys around? :)

> Regarding building a SMS "RAM" cart:

> Dallas Semiconductor (www.dalsemi.com) has an interesting memory device they call NV-SRAM. It's a RAM chip that includes on on-board battery that is automatically enabled once power (Vcc, specifically) is removed from the chip, thus allow the cartridge to store data indefinitely (the manufactures claim the batter lasts up to 10 years). Additionally, there are sizes up 16 Megabit (i.e., FOUR times the size required by standard SMS games.)

I would much prefer to use Flash memory, but that may just be because I'm more familiar with it (I'm also concerned about the possibility of a game checking for this kind of stuff as a copy protect).

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> The difficulty is creating the paging logic. I believe it could easily be done with a PAL, but I lack the tools to create my own custom PAL chips.

Always the paging logic. A rough guess at the component count for a discrete-logic version is 5 or more chips. I could probably design it that way, but I'd rather not.

On the other paw, I currently have access to a universal programmer that should suffice for programming PALs, and I have no problem with learning how to write the logic for one (except time, of course).

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> Since the whole design fits on two chips, a board could be created that would easily fit into a standard SMS cartridge case.

Would it still fit if one were to use sockets for all the chips? (so that new PALs could be made and tested in short order and so that one could save a programmed ROM for later)

What about hookups for a battery and a static RAM? (three chips and a battery fit (phantasy star), what about four?)

What about using a PLCC package for the ROM as opposed to a DIP? (probably more expensive, more of a pain to solder, but smaller)

Quote
> Again, I lack the tools necessary to complete such a project, but would be happy to help out. I have experience building a (working) SMS cartridge copier.

I may be able to design this. I can certainly code it. It is not given me to be able to build it (yet).

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> Eric Quinn

--Nyef
 
Paul
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Well, you could use a.... :)
Post Posted: Tue Nov 02, 1999 2:27 am
Magic Drive Plus (and probably Super Magic Drive, but I never tried it back when I had one) copier on a Megadrive/Genesis will let you play master system games normally (and also gamegear games, but with screwed up palette and controls). Since megadrive/genesis has this SMS 'compatibility mode', it should be pretty close to what you want to do without having to build anything of your own :)

This doesnt work on other MD/Genesis copiers as far as I know (I know for sure it doesnt work on Double Pro Fighter/SmartBros, unless there is a trick I never found out hehe). It is accessed by adding a special SMD header to the SMS rom images which tells the copier to switch into SMS mode. If you own a Magic Drive and want to know I will search my old texts for the bytes you need to set in the header...
 
Michael
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Re: Well, you could use a.... :)
Post Posted: Wed Nov 10, 1999 2:40 am
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> Magic Drive Plus (and probably Super Magic Drive, but I never tried it back when I had one) copier on a Megadrive/Genesis will let you play master system games normally (and also gamegear games, but with screwed up palette and controls). Since megadrive/genesis has this SMS 'compatibility mode', it should be pretty close to what you want to do without having to build anything of your own :)

WOW!! Where do I get one? How much would one cost?
 
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