Author Topic: Just thinking about a replacement for a HuCard slot  (Read 643 times)

soop

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Just thinking about a replacement for a HuCard slot
« on: June 28, 2012, 03:00:42 AM »
Just searching "38 pin socket" and came up with this: http://www.allelectronics.com/make-a-store/item/HST-338/3-X-38-PIN-HEADER-SNAPPABLE/1.html - no idea about the dimensions.

Anybody ever find anything close, or moddable?

Necromancer

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Re: Just thinking about a replacement for a HuCard slot
« Reply #1 on: June 28, 2012, 04:04:35 AM »
I guess you missed this one: linky.  Similar to the region converters sold by TZD, he used a PCI connector, removing the pins on the bottom side and widening the slot a bit with a dremel.
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MottZilla

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Re: Just thinking about a replacement for a HuCard slot
« Reply #2 on: June 28, 2012, 09:36:31 AM »
That's great, now all we need is to add a boot rom and patching support sort of like Game Genie and make a pcb. ;)

soop

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Re: Just thinking about a replacement for a HuCard slot
« Reply #3 on: June 29, 2012, 03:34:25 AM »
I guess you missed this one: linky.  Similar to the region converters sold by TZD, he used a PCI connector, removing the pins on the bottom side and widening the slot a bit with a dremel.


Ah perfect, I forgot about that.  I just ordered one, so I'll try and replicate it.

Mishran

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Re: Just thinking about a replacement for a HuCard slot
« Reply #4 on: June 29, 2012, 06:39:15 AM »
A game genie/shark type device would be a cool idea, but I don't see it happening.

MottZilla

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Re: Just thinking about a replacement for a HuCard slot
« Reply #5 on: June 29, 2012, 04:18:56 PM »
It's not so far fetched. The operation of such a device could easily be made by one individual. Just design the pcb, order them from somewhere, mount the components. It's not beyond the great flash carts and other projects people have already done.

Mishran

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Re: Just thinking about a replacement for a HuCard slot
« Reply #6 on: June 30, 2012, 02:09:20 AM »
But such a device isn't highly sought, so it wouldn't be worth a person's time and money to design and manufacture such a device unless it is embedded into a flash cart.

MottZilla

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Re: Just thinking about a replacement for a HuCard slot
« Reply #7 on: June 30, 2012, 06:56:16 AM »
I don't think it would actually cost that much to make. PCBs are not terribly expensive. You wouldn't need a very expensive CPLD, and you could use any cheap 8bit eprom or flash memory to hold a BIOS. Now it's probably true that it wouldn't be extremely popular since it would be for those without region mods or both region systems, or those that want to use cheat codes. But I think such a device could be made, at the very least you could make new converters that don't do anything but swap the address lines but are on a PCB with a connector. I wouldn't mind having one as if I did I might consider opening my DUO-R and soldering a wire to the cpu to allow it to get past the software region check in US games and then be able to collect the US versions of certain games. Alternatively and less desirable I could collect the US games and then play them by instead flashing the images to flash cards. Not nearly as nice.

TheOldMan

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Re: Just thinking about a replacement for a HuCard slot
« Reply #8 on: June 30, 2012, 10:15:18 AM »
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A game genie/shark type device would be a cool idea, but I don't see it happening.
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It's not so far fetched. The operation of such a device could easily be made by one individual. Just design the pcb, order them from somewhere, mount the components. It's not beyond the great flash carts and other projects people have already done.

And how would you get cheats to work?? You would need a routine to monitor the interrupts so you could re-write RAM. I'm not sure you could do that, given that the irq routines on a tg16 can be anywhere. At the least you would have to decode the top bytes of the card addresses so your patch irq routine could run. Then you would have to call the card irq routine. Which is a problem, because of the way interrupts have to be acknowledged....

Not saying it -couldn't- be done. I just don't see a good way to do a game-genie kinda thing.
A line swapper, that's bloody easy, though. Mount Blue's circuit on a full size card, with a switch to control us/jp.
No problem, except for the connector..


MottZilla

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Re: Just thinking about a replacement for a HuCard slot
« Reply #9 on: June 30, 2012, 01:34:12 PM »
Game Genie would be easier. Game Genie monitors the access of ROM and patches values (which would be needed to crack region protection) so you could easily develop cheat codes on the same principal, afterall that's what Game Genie does. Now you are right about GameShark, that is a different cheat system more like Pro Action Replay. Those devices steal an interrupt, probably NMI, to rewrite RAM values every frame. This is more likely to cause problems than ROM patch codes like Game Genie.

The connector apparently you can use one of these 32bit PCI card connectors was it? You just physically modify it a bit and you're good to go apparently.

So again, Game Genie type ROM patching should be doable. Game Genie works usually by a simple encoded string that contains the address to intercept and the value to replace with. On NES and Gameboy they also have "Compare" values due to bankswitching. I don't think that is needed for PC-Engine since the cartridge connector has all the address lines for an 8 megabit ROM, so only SF2CE would be left out.

It seems doable to me, you just need a boot rom/bios to enter patch codes which will in turn configure registers on a CPLD for what addresses it should be looking to intercept and respond to. I mean basically we are just talking about making a game genie for PC-Engine/Turbografx 16 which could easily have been done back in the 90s if they wanted, plus adding a region pin swapping.

TheOldMan

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Re: Just thinking about a replacement for a HuCard slot
« Reply #10 on: June 30, 2012, 02:47:28 PM »
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You just physically modify it a bit and you're good to go apparently.
<lol> Look up what it takes to mod a pci card connector :)

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Game Genie works usually by a simple encoded string that contains the address to intercept and the value to replace with. On NES and Gameboy they also have "Compare" values due to bankswitching

I get the idea, but there's a couple of problems.
  1) Some cards user a large rom and a smaller rom, with the smaller rom mirrored. So, you would need 2 code slots to catch both.
  2) To replace the data, you would have to disconnect the rom from the data lines (ie, disable the rom) so you could put the new data on the lines without conflict. Most eeproms take longer to switch on than to access a location, so you would prossibly have timing problems....Though you might get away with it since the tg16 roms are pretty slow by today's standards...

Still, it -might- work....Just not sure exactly how...



TailChao

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Re: Just thinking about a replacement for a HuCard slot
« Reply #11 on: July 01, 2012, 03:25:57 AM »
  2) To replace the data, you would have to disconnect the rom from the data lines (ie, disable the rom) so you could put the new data on the lines without conflict. Most eeproms take longer to switch on than to access a location, so you would prossibly have timing problems....Though you might get away with it since the tg16 roms are pretty slow by today's standards...
If the theoretical HuGenie is just controlling the original cards' OE line, it shouldn't be too large of an issue as long as your address comparator is fast enough. Essentially don't enable ROM output until the device is sure that it's not a "patched" address, but everything else is still passed so the original ROM will still be able to go and fetch the data (CE is still asserted), just not output it on the bus. That would compensate for slower ROMs as much as possible.
But yeah, trying to find new HuCard slots is the biggest issue here.

HercTNT

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Re: Just thinking about a replacement for a HuCard slot
« Reply #12 on: July 01, 2012, 03:56:03 AM »
I'm with Mish. Not sure how many people would use a game genie on a turbo system. Now, make a device that acts like a real time hardware save state like this device:

http://www.swapmagic3.com/superufopro8/content.asp?id=6

MottZilla

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Re: Just thinking about a replacement for a HuCard slot
« Reply #13 on: July 01, 2012, 04:34:40 AM »
I didn't look at what all you had to do to mod the connector. But alternatively it's possible to get some chinese factory to make HuCard connectors for you these days. If you have the money.

While some HuCards mirror data throughout the address space, like many systems that mirror ROM, they don't likely rely on that. They probably only access the code or data at one location in the address map. So you most likely would not need two codes.

Really such a device would be nice, but a region modification is more practical. That's what I'll eventually do.

TheOldMan

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Re: Just thinking about a replacement for a HuCard slot
« Reply #14 on: July 01, 2012, 04:57:39 AM »
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But alternatively it's possible to get some chinese factory to make HuCard connectors for you these days. If you have the money.

But I don't <sigh>.

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While some HuCards mirror data throughout the address space, like many systems that mirror ROM, they don't likely rely on that. They probably only access the code or data at one location in the address map. So you most likely would not need two codes.

If that were true, they would work fine on a flash card, without mirroring, wouldn't they?

I don't know all that much about how the HuCard electronics were actually done, or how the roms were dumped.
But I do know that making dumps work on a flash card requires that some data be duplicated to make them work...

I do wonder if different eeprom setups used different address lines for CE and OE on the roms. Seems to me that is the easiest way to use different size eeproms, and it would cause the eeproms to be mirrored at different addresses.
So maybe the problem is caused by the way the cards were dumped, and it would work okay with a single compare.