Projects in progress

[kendrick]

In an effort to stave off holiday boredom and ennui, I start this off-topic topic about what kinds of gaming and mod projects our strange and off-putting club is presently engaged in. If you're working on something that would interest the teeming masses here on GameSX, please share and perhaps you'll gather praise or inspire imitators.

A retailer I trust (www.goatstore.com) is liquidating Genesis/Megadrive Mark I consoles for $2.00 a pop. It's not such a great bargain once you figure in shipping, but I have three on order anyway. One I may resell to the local game shop to recoup costs, and they've been lusting after a Genesis anyway as they have something on the order of $50,000 in Genesis cartridge inventory and no console to go along with it. The other two I plan on using for invasive, life-changing mods. One is going to have every video mod known to man applied to it, and the other is going to get a transfusion of Dreamcast parts. To what end yet I know not.

In a fit of fiscal irresponsibility I ordered a Virtua Fighter 2 arcade board. The Sega Model 2A PCB is unique in that it's not quite Jamma-compatible, and requires a 24 kHz RGB monitor for proper video output. I may end up carting home a Sega arcade cabinet and monitor in the next week or two. Barring that, I plan to do a little research to see what monitors can be bent to accept that level of sync. I have this mental image of wandering around one of the local computer shows carrying the board in a briefcase, with an AC plug and three BNC connectors hanging out of it so I can try out monitors before I buy.

Also in the hopper is a clipboard full of stupid tricks to perform with a Compact Flash to IDE adapter. I learned only recently that CF and IDE are pretty much pin-for-pin protocol compatible, and so it's trivial to substitute one storage device for another. However, the practical limitation to substituting flash memory for a hard drive is that flash memory can withstand only a limited number of write actions before going belly up. The solution comes from professional-grade server hardware, which makes use of a battery-backed cache that queues up disk writes so that you don't lose data if the power goes out. The relevant part of that technology is to limit the number of write actions so that they occur all at once over regulated intervals. This is all by way of trying to engineer an Xbox that has no moving parts at all, apart from a fan.

Well, that's my list of pipe dreams in progress. What are *you* working on? I'm interested to know.

-KKC,

[Guest]

I have been reading a bit about Mega Drive overclocking and plan to mod my system in a similar way.

Hoping to get rid of the slowdown in Thunder Force IV and I'll learn in the process as well.

[kripp]

Right now im trying to hunt down an RGB monitor locally, no luck so far. I do have an arcade monitor that I do not use, but im not big on the idea of having one of my projects kill me. Once I have a monitor I would like to start adding RGB output to my consoles that support it.

Thats about all thats on my menu for the next while, should keep me busy.

Thanks.

[TJ_Kat]

i'm still working on my s-vid and component switch boxes. i have all the materials and plans ready to go, it's just a matter of getting off my lazy ass and over to my grandpa's to use his drill press and table saw.

many dreamcast mods. except i'm currently lacking a working dreamcast.

building a couple of twinsticks for virtual on. same problem as the switchs. everything's ready to go, i'm just too lazy to drive across town.

those are my works in progress. i have a whole other big list of stuff i haven't started yet.

[atom]

Wow kendrick, looks like you got your hands full.

-ahb, who wonders why kkc didnt do that cool spur of the moment signature thingy

[Aidan]

The relevant part of that technology is to limit the number of write actions so that they occur all at once over regulated intervals.

Whilst FLASH only suvives a limited amount of writes, it's split up into a number of 'pages'. When you come to write, you erase a page (IE, set the bits back to 1), and then write all the 0 into it. That way, when the FLASH does start to die, it tends to do it a page at a time, rather than the whole chip.

What would be a different approach would be to rotate pages on the FLASH, so that the next write to the same sector on the disk would end up writing to a different page on the FLASH. This, of course, has the disadvantage that you need to keep track of which page maps to which sector. Sony do something similar with their memory stick to try and avoid problems. Their system also allows pages to be mapped out when they do go faulty. Incidently, some compact flash controllers automatically do this already. However, I don't know how you find out if the controller on the CF is actually going to be doing this or not.

Obviously with the caching idea, you're going to hit a point where you can't store everything in the cache and you have to flush data out. On the other hand, profiling the reads verses writes might give you an idea of just how much a problem it might or might not be.  

[benzaldehyde]

I am working on controller mods. Lots of 'em.

[DaveJ-UK]

Right now im trying to hunt down an RGB monitor locally, no luck so far. I do have an arcade monitor that I do not use, but im not big on the idea of having one of my projects kill me. Once I have a monitor I would like to start adding RGB output to my consoles that support it.

Thats about all thats on my menu for the next while, should keep me busy.

Thanks.

Monitors aren't as dangerous as you might think. It's only the tubes high voltage that's dangerous, and that's safely contained within the tube unless you remove the anode (the suction-cup-type-thing that runs to the flyback transformer).

If you just want to hook up the RGB inputs, that should be a piece of cake. If you want to work on the chasis then just read up on how to safely discharge the tube (easily done with a long screew driver and a bit of electrical cable).

The only thing I'd never mess with is a micro-wave.

[kripp]

I may just have to consider pissing around with my arcade display now! What I would really like to do is get the entire cabinet up and going again. I bought a new JAMMA harness a couple of years ago and never bothered to hook things up, im thinking its because I don't know what im doing! I tried it once and blew some fuse, thats about as far as I got with that.

The only thing I would never mess around with is a cobra!

[DaveJ-UK]

The only thing I would never mess around with is a cobra!

That made me laugh.

Where were you blowing fuses? (sorry to hijack the thread; perhaps create a new one?)

If you have a standard 3 button JAMMA cabinet, the wiring should be pretty simple.

And what monitor do you have?

[Adeptus]

Shoestring budget Supergun... still in planning stages...

My parts list so far includes:
one of those N-PAL convertors (CXA1145 or 1645 based, as mentioned in another thread) to output video to composite;
[edit] a car audio impedance convertor to convert the speaker output to line level, safe for TV audio input;
an old PC power supply;
and a JAMMA harness.

I have a couple of 2-player joysticks for old consoles (NES/SNES/MS/MD/Atari) made with real arcade parts, I just need to rewire one to bypass the encoder PCB & hook up to a 25-pin cable.

The other stick I'm planning to rewire to PSX, to then work on most modern consoles via adaptors

[Aidan]

Monitors aren't as dangerous as you might think. It's only the tubes high voltage that's dangerous, and that's safely contained within the tube unless you remove the anode (the suction-cup-type-thing that runs to the flyback transformer).

Unless you have the misfortune to be working on a TV or monitor with a floating chassis. That typically means they've connected to around half the mains potential. In the UK, that'd put the chassis at 120V or so, and is quite capable of killing people.

The beam forming components can be fed with relatively high voltages too. The tube's HT supply might well be lethally high at voltages as much as 24,000V, but voltages over 60V are equally good for killing and there's plenty of those around the tube and not necessarily enclosed either.

[TJ_Kat]

Monitors aren't as dangerous as you might think. It's only the tubes high voltage that's dangerous, and that's safely contained within the tube unless you remove the anode (the suction-cup-type-thing that runs to the flyback transformer).

In school, I don't think they ever mentionned the tube when discussing why not to take apart monitors. We were always told it was the charge in some of the capacitors that would kill you. Same as with a power supply.

[DaveJ-UK]

Unless you have the misfortune to be working on a TV or monitor with a floating chassis. That typically means they've connected to around half the mains potential. In the UK, that'd put the chassis at 120V or so, and is quite capable of killing people.

The beam forming components can be fed with relatively high voltages too. The tube's HT supply might well be lethally high at voltages as much as 24,000V, but voltages over 60V are equally good for killing and there's plenty of those around the tube and not necessarily enclosed either.

I've only worked with Hantarex and WG monitor's (and a Sony Trinitron once) and I'm not exactly a qualified technician, but I always understood that this live chasis business was only ever used in cheapo Russian monitors made in the 70's.

Discharging capacitors is the same as discharging the tube (which is actually a giant capacitor itself). You don't normally have more than a couple of high voltage caps on the chasis and they're easily identifiable.

If you leave it turned off for a few days, you can be pretty confident it will have lost its charge on its own but you should always go through the routine just to be sure.

[NFG]

Arcade monitors use an isolation transformer to safely power the display.  It's shockingly common for operators to skip this and power the monitor directly from the mains, and this creates a perfectly functional monitor, as well as a live, dangerously high-voltage monitor chassis.

Also, discharging the tube once isn't enough.  Do it once, wait a few minutes, and do it again.

[Aidan]

Don't assume that the bleeding resistors on capacitors are functional either. I have come across cases where they have failed, leaving residual high voltage across parts. When it comes to safety, it just isn't worth taking chances.

[MARCUS CROY]

HI guys,

  I just joined up today. I have being watching this site for some time and all i can say is COOL!!!  Anyway i've done a simple mod on one of my Playstation 2 controllers. All i did was swap out the motor with the less weight on it. And soldered a motor from a Nintendo 64 rumble pak. And boy does it ever kick!!

     What do you think of it??