FPGA Based Videogame System

[CZroe]

 

The jailbroken software, cartridges with onboard saves, or an Everdrive will only be writing something when you've saved your game. It's as easy to avoid with how he's doing it as it is with the physical power button.

 

There's no protection built into the system's firmware to prevent you from hitting the power button at the wrong time. You just don't do it at the wrong moment such as at the split second you've exited back to the system menu in a game with onboard save capabilities that you're playing via the SD card. Same with how he's cutting power when switching to another HDMI port or turning his tv off.

...except that the button is a software button and does not just kill power. It goes through some kind of a shutdown process... just like your phone. That sure seems like protection built in to the systems firmware to me and certainly not something I’d be comfortable bypassing with the “Eco” port on a power strip. Super Nt was the same way. Heck, SNES CE and NES CE were the same way.

 

System settings are saved internally but it’s probably possible to corrupt those too. Hopefully powering off between core changes doesn’t affect the FPGA too much.

 

With SNES many games used the SRAM as work RAM. This meant that the SRAM was being near constantly accessed and changed. Rather than wear out your storage with continuous reads/writes, it made more sense to cache it in memory and save regularly. If you are done playing and hit save right before you kill the power, there’s a chance that you could lose your progress and/or corrupt your filesystem... even if the game says you saved successfully. I don’t know if any Genesis games ever use SRAM in this way but, if so, this is possible. I definitely wouldn’t be comfortable yanking the cord after copying Sega CD Backup RAM, that’s for sure.

 

The device seems to have a shut-down procedure instead of a power insta-kill switch, so I’d assume there’s a reason for it and do a proper shut down. Of course, I’m likely not getting one every time the system reboots when I try to shutdown.

 

 

I haven’t had any static shocks at all. I wonder why this is happening for some and not for others?

Yeah I don't either, but in my apartment I've got a hardwood floor and never get static shocks on anything.

 

At work, there's a carpet which I swear, I don't have to do much to get a big zap from touching any metal. I always have to 'discharge' myself by touching the metal handle on the door, get a shock, so that I can safely remove some USB sticks (iLoks) which I used to get shocked with unless I touch the door handle first. It would worry me, as my iLoks are extremely important and if I lost them to corrupted data I'd be screwed for a while.

 

Anyways, are those who are getting shocked wearing shoes on a carpet? Cuz that'll do it.

Well, I haven’t felt/noticed a shock but my twin brother has and we have hardwood floors. I may not have felt/noticed the shock myself but I bet the static is still discharging, since I’ve had the system reboot instead of shutdown many times.

 

This deep and involved, rigorous twin-study, along with reports from the likes of Enragedwhale, shows that it’s still happening even when some of us don’t notice the shock. One day, it will also show the effect Mega Sg has on our DNA in space.

[Drunk_Caterpillar]

I have hardwood floors in my place and the shocks have been BRUTAL.

Edited April 14, 2019 by Drunk_Caterpillar

[Kaide]

With SNES many games used the SRAM as work RAM. This meant that the SRAM was being near constantly accessed and changed. Rather than wear out your storage with continuous reads/writes, it made more sense to cache it in memory and save regularly. If you are done playing and hit save right before you kill the power, there’s a chance that you could lose your progress and/or corrupt your filesystem... even if the game says you saved successfully. I don’t know if any Genesis games ever use SRAM in this way but, if so, this is possible. I definitely wouldn’t be comfortable yanking the cord after copying Sega CD Backup RAM, that’s for sure.

 

With games that saved to SRAM (vs EEPROM or MRAM), losing power to the SRAM causes the save data to be lost. The battery is there to provide continuous power to the SRAM. Interrupting power to the console is not the problem, as the original consoles cut power to the PCB/cart when the power switch was opened.

 

The issues you bring up happen in situations where there’s a cache, and the cache is then written out somewhere. Original carts don’t fall into this category. Instead, it is mostly more modern things like Everdrives, since the SRAM content has to be swapped out when switching ROMs. The JB firmware is probably similar, but I’m not sure when it moves the contents of SRAM to the SD Card.

 

There’s no real reason the Mega SG or Super NT need to “cache” anything itself without the JB.

[Kismet]

I have hardwood floors in my place and the shocks have been BRUTAL.

 

I have hardwood floors and haven't had any zaps at all in this place.

 

At work though, I get static zaps all the time around laptop touchpad buttons. Haven't recently but that's due to a change in the humidity, as it's typically only a winter condition.

 

I'm thinking if the zaps are brutal these might be a grounding issue. My Mega SG is plugged into the Super NT's USB power supply which is plugged into a surge protector which is plugged into a UPS (The UPS inverter circuit is toast however) though.

[CZroe]

With games that saved to SRAM (vs EEPROM or MRAM), losing power to the SRAM causes the save data to be lost. The battery is there to provide continuous power to the SRAM. Interrupting power to the console is not the problem, as the original consoles cut power to the PCB/cart when the power switch was opened.

 

The issues you bring up happen in situations where there’s a cache, and the cache is then written out somewhere. Original carts don’t fall into this category. Instead, it is mostly more modern things like Everdrives, since the SRAM content has to be swapped out when switching ROMs. The JB firmware is probably similar, but I’m not sure when it moves the contents of SRAM to the SD Card.

 

There’s no real reason the Mega SG or Super NT need to “cache” anything itself without the JB.

Yes. I’m talking about the way it handles SRAM for the jailbreak as one example of what can happen. Who knows what all is being cached in memory. It certainly doesn’t go insta-off when you push Power. It’s doing something. If the creators think it has to shut down why do we think it doesn’t strongly enough that we’d argue in favor of pulling the power and skipping shut-down? Until Kevin weighs in, that’s the crux of what I’m saying. Edited April 14, 2019 by CZroe

[Atariboy]

SRAM isn't used in the manner you've described, CZroe. And like I've already said, it only writes to the SD card with the jailbroken software when you've exited your game after manually saving it. So not only does it not apply for the majority of SNES games, but it also virtually never will apply for the Mega SG. All you have to do is not shut down the system at the split second you've returned to the system menu from a save capable game.

 

...except that the button is a software button and does not just kill power. It goes through some kind of a shutdown process... just like your phone.

 

Seen no evidence of this myself of the system going through some shutdown procedure and even if it did, I really doubt it's taking into account that's going on with the SNES core at that particular moment in time (Or Genesis core) by delaying the procedure until some process has concluded.

Edited April 14, 2019 by Atariboy

[Kaide]

Yes. I’m talking about the way it handles SRAM for the jailbreak as one example of what can happen. Who knows what all is being cached in memory. It certainly doesn’t go insta-off when you push Power. It’s doing something. If the creators think it has to shut down why do we think it doesn’t strongly enough that we’d argue in favor of pulling the power and skipping shut-down? Until Kevin weighs in, that’s the crux of what I’m saying.

What do you think is being “cached” beyond the SRAM? Settings have to be saved out manually to the built-in NAND that holds the firmware. It’s thrown away on power off. Same with the simulated SRAM.

 

Everything else that would be loaded is R/O, or part of the system’s internal state that can be thrown away on power off.

 

Honestly, power on/off isn’t instant because it is a momentary switch. It isn’t an on/off switch. Something has to poll/trigger off the switch being pressed to turn on or off. Latency isn’t exactly a high priority for such a circuit, and I’d imagine vampire draw is a bigger concern.

 

The thing is, while your suggestion is prudent for many systems that run a full blown OS in them with HDDs/SSDs that have internal write caches, etc... here not so much. I think you’re reading more into this than there is.

[Kaide]

(Double Post)

Edited April 14, 2019 by Kaide

[Razzie.P]

No shocks here so far, luckily. I have the USA version.

[Fafner]

No shocks for me either!

US version as well.

[RetrogamerX]

No shocks here. EU version

[atmn]

No schocks here either, US version.

 

Using this to power the Sg:

https://www.ikea.com/se/sv/catalog/products/90280826/

[zetastrike]

Analogue replied to my request. They're blaming it on things like the humidity, carpet, and the clothes I'm wearing. They also asked if I'm using all the cables and psu included with the console. They suggested using a different TV or removing any surge protector/power strip and plugging it directly into the wall.

 

I explained to them that I have a bunch of other consoles, including the Super NT, connected to the same setup and they never shock me. I also mentioned that I know I'm not the only one experiencing this.

 

I'm starting to think there's something wrong with the power button's design.

 

I never plug consoles or TVs directly into the wall.

 

Sent from my SAMSUNG-SM-J727AZ using Tapatalk

Edited April 15, 2019 by zetastrike

[Toth]

For anyone who doesn't follow Twitter, Firmware 4.4 has released.

 

https://twitter.com/analogue/status/1117773768544243712

[RetrogamerX]

For anyone who doesn't follow Twitter, Firmware 4.4 has released.

 

https://twitter.com/analogue/status/1117773768544243712

 

Hope they do 4.4 jailbreak? It's good to have more options

[Razzie.P]

Analogue replied to my request. They're blaming it on things like the humidity, carpet, and the clothes I'm wearing.

 

 

 

 

They really should have included some sort of FYI that it was meant to be played naked while taking a bath. That would have prevented some of these issues, I guess.

[lame gag]

For anyone who doesn't follow Twitter, Firmware 4.4 has released.

 

https://twitter.com/analogue/status/1117773768544243712

That's interesting. I played through Final Fight CD and the games backgrounds were getting progressively worse the further I got. The background on the final boss was completely broken. This may help with it.

[killersquirel]

I have hardwood floors in my place and the shocks have been BRUTAL.

 

Have you tried putting the rubber mat that was included for connecting it to the Sega CD under the system? I would think that would stop the shocks.

[CZroe]

 

Have you tried putting the rubber mat that was included for connecting it to the Sega CD under the system? I would think that would stop the shocks.

Mine was on the mat when it shocked my brother.

[Razzie.P]

I feel like this has been asked before in this thread, but my search isn't finding anything -- does the Super NT work properly with a Snes Power Pack? I got one from Retro USB a few years ago, and all games (that I've tested) work fine on my real SNES systems, but when trying to load a game on the Super NT, I get an error reaching "No Internal Header Found"

[Atariboy]

Super Powerpak is compatible. I don't own a Super Powerpak so I'm not familiar with your error, but I do know that you're supposed to check the box labeled "use launch system timing" under the Super NT's hardware menu. I'd go double check that before proceeding since I suspect it's likely your issue if the same roms work fine on original hardware.

Edited April 16, 2019 by Atariboy

[Razzie.P]

Super Powerpak is compatible. I don't own a Super Powerpak so I'm not familiar with your error, but I do know that you're supposed to check the box labeled "use launch system timing" under the Super NT's hardware menu. I'd go double check that before proceeding since I suspect it's likely your issue if the same roms work fine on original hardware.

 

 

That did it! Thank you!

[vanfanel]

The misterious organization (heh, doesnt it sound like an arcade or NES introduction text?) that has been releasing JB firwares is again at it!

 

Updated JB firmware available on the usual place!

[zetastrike]

The misterious organization (heh, doesnt it sound like an arcade or NES introduction text?) that has been releasing JB firwares is again at it!

 

Updated JB firmware available on the usual place!

Does it add anything cool, or just incorporate the fixes from the official firmware? Github won't load for me right now for some reason.

 

Sent from my SAMSUNG-SM-J727AZ using Tapatalk

[vanfanel]

Does it add anything cool, or just incorporate the fixes from the official firmware? Github won't load for me right now for some reason.

 

Sent from my SAMSUNG-SM-J727AZ using Tapatalk

Whoa!! As if fixes were not cool enough, man

 

It also fixes some Colecovision games (remember the MegaSG is also a fantastic Colecovision machine)

 

Here is the list of the news:

JB7.4 2019-04-16

    includes all fixes from official firmware v4.4:
        Sega CD - adjusted timing i.e. Mickey Mania
        Overdrive 2 demo is 100%
        X-men 2 character select fixed
        Fixed player 2 XYZ (6 buttons)
        Allow no controller on player 2
        SMS fixes for X7 and flash everdrive
        You now stay in the file browser when selecting a font
        Changed "hotkeys" to "hotkeys & controllers"
    plus:
        Sega CD BIOS substitution works properly now on games like snatcher
        Fixed speech on Coleco Wizard of Wor
        Fixed random crashes in Wizard of Wor and majikazo
        Fixed graphics issue on Juno First and Astrododge
        Fixed sprites sticking around between games
        Added warning: CD BIOS replacer only works if fix region is turned on
        SMS BIOS now also works for cartridges
        Game gear buffer changed to zero delay by default
    PDF user guide with documentation