Overclocked Genesis - Cooked!

[blackevilweredragon]

Well well well, I tried the famous 13.4MHz overclock on my Genesis, and what do you know, I kill the 68K..  Mine was the MC68000, the one that was supposed to overclock to 13.4MHz easily..  Nope, mine didn't..  It worked for a bit, then froze, and never came back.

I'm not upset or anything (i knew the disclaimer), I'm just warning people that want to do the overclock, it doesn't work all the time.

(i lucked out and had a ceramic 68k at my friends house, whom let me take TWO of them)..

[RobIvy64]

Dude, overclocking a Genesis will not kill it or hurt it in any way unless there was a problem with the install, like crossed wires.

You could overclock the the CPU to 800 MHz+ and it would not kill it... it wouldn't run at that high of a speed, but you could set it back to 7.6 MHz and all would be well.

My guess is that you crossed pins with the VCC that is located next to the clock pin and toasted the 68K.  

[Epicenter]

Technically, shorting those two points could destroy the clock divisor circuitry in the GLU chip but I doubt it would damage the processor at all, since the clock signal is just a 5V pulse interspersed with 0V on the same line-- shorting VCC (5v) to it would just be a worthless constant signal. But shorting an output (voltage line) to an output (clock) on the GLU chip like that is very potentially damaging.

And it's quite likely what killed the OP's MD. (it could also have blown up your 7805s, the power regulators. Does the LED still come on when you fire up the system? Or does it power up but sit on the Black Screen of Death?) Clock changes should never damage a processor, period.

[blackevilweredragon]

Dude, overclocking a Genesis will not kill it or hurt it in any way unless there was a problem with the install, like crossed wires.

You could overclock the the CPU to 800 MHz+ and it would not kill it... it wouldn't run at that high of a speed, but you could set it back to 7.6 MHz and all would be well.

My guess is that you crossed pins with the VCC that is located next to the clock pin and toasted the 68K.

nope, no crossed wires..  i was EXTREMELY careful NOT to do that...

not all processors overclock well..  you do know they get them from wafer boards, and aren't even designed at a certain speed...  they are rated them..  sometimes they are underated, sometimes they are over-rated...

i remember when I bought a Pentium 133MHz CPU..  it would work at 120MHz fine, but at 133MHz, the chip died *which obviously i was entitled to a replacement*

anyone saying overclocking won't kill, needs to learn how CPUs work, a little more...  just do a Google search, it's all over the net, AND certifications (like my A+ cert)

[blackevilweredragon]

Technically, shorting those two points could destroy the clock divisor circuitry in the GLU chip but I doubt it would damage the processor at all, since the clock signal is just a 5V pulse interspersed with 0V on the same line-- shorting VCC (5v) to it would just be a worthless constant signal. But shorting an output (voltage line) to an output (clock) on the GLU chip like that is very potentially damaging.

And it's quite likely what killed the OP's MD. (it could also have blown up your 7805s, the power regulators. Does the LED still come on when you fire up the system? Or does it power up but sit on the Black Screen of Death?) Clock changes should never damage a processor, period.

but i soldered in another 68000, and everything is working again...

[Epicenter]

You're not one to talk. You're demonstrating your own understanding of microprocessor theory to be significantly lacking.

Processors die from overvolting, or overheating causing electromigration to damage it. A 68000 produces nowhere near the amount of heat required to easily die of electromigration (this is something you'd see in a modern high-wattage PC processor, for example) and you are not altering its input voltage. Providing a corrupt clock signal or a very high frequency is harmless, but the chip won't operate like that. It won't, however, be damaged.

The only potential way to fry a 68000 by overclocking would be if you were to provide, say, a 5 GHz clock to its CLK pin .. or just a constant 5v ... and let it run for HOURS. I find it unlikely you did this.

[blackevilweredragon]

im not one to talk?  fuck, i must be retarded to even have certifications in electronics....

my ceramic 68000 CPU gets to 96f at 7.6MHz...  i know how CPUs are made...  don't EVER doubt me, as I don't doubt you guys...

[RobIvy64]

5 GHz 68K, now *THATS* blast processing!

[blackevilweredragon]

yes, it would..

what IM trying to say, some 68000 don't take over-clocking good..  some can get too hot, and get damaged..

my IR thermal system caught the 68000 at 96f at normal operation..  some get even hotter, some get hardly hot at all..  When they get the wafers off the assembly line, they don't know the speed of the CPU, until it's tested..  they keep pushing the CPU until it starts producing errors, then it's backed down a certain percentage set by the factory, then it's labeled it's speed...

[Epicenter]

96F? Terrifying That's 35.5C. The MC68000P8's max operational temperature spec at its surface is approximately 105C. Therefore its maximum rated junction temperature is much higher. My MC68000P8 runs much warmer than yours does, naturally, at 25.4 MHz. And it's been running that way for a very long time.

You did something wrong. Admit it.

[RobIvy64]

I've overclocked over a dozen Genesis systems without any problems at all and they still run fine today. I'll admit one did die, because I was a newbie and made a mistake, it does happen occasionally even to experienced modders.

[Epicenter]

I wonder if he even took basic ESD precautions. Static electricity is usually in the tens of thousands of volts, and can easily destroy a 68000 or any integrated circuit.

[blackevilweredragon]

but I tested EVERYTHING before finalizing a hack..  I use a low-voltage continuity tester (.01v), and there was no shorts where I soldered..  everything checked out..

It was working fine, perfectly fine when overclocked..  the chip got a bit hot to the touch, then it froze up with the top half of the Sonic 2 split screen turning into ";;;;;;;;;;", then it never came back..

If I did something wrong, I doubt it would have booted at all, it would have died from the start...  I even had friends watching the overclock, some even engineers, and they all said it got "cooked", because they felt it was hot to the touch..

(the one running at 95f is my "replacement" CPU..)

(oh yea, soldering iron set to the lowest temperature of the solder, and only held against a pin for no longer than 1 second..)

[Joe Redifer]

5 GHz 68K, now *THATS* blast processing!

But YOU said Blast Processing comes from the VDP.  Tom Kilanske did not invent the VDP.  Well actually I guess he did.  And no, your Pontiac does not have Blast Processing because when Pontiac called Tom Kilanske and asked him if they could use it, he said "no" and hung up.  Then he went to the restroom and dropped a man-sized load and didn't flush.

[blackevilweredragon]

I wonder if he even took basic ESD precautions. :rolleyes:

DUH!!!  that's the number 1 rule..

but you still failed to explain the:  how it was running in the first place..  if it was a static discharge, it would have fried it INSTANTLY...

[RobIvy64]

The 68000 was not invented by Sega of America's president from 1990-1996. The 68000 was developed by Motorola in the mid-late 70's, far before the Genesis was even concieved.

Sega decided to use the 68000 in it's console, so they struck a deal with Motorola, Hitachi, and Signetics to supply the *already designed* CPU for use.

And yes, my Pontiac did have a 68K as it's ECU controller.

[Epicenter]

5 GHz 68K, now *THATS* blast processing!

But YOU said Blast Processing comes from the VDP.  Tom Kilanske did not invent the VDP.  Well actually I guess he did.  And no, your Pontiac does not have Blast Processing because when Pontiac called Tom Kilanske and asked him if they could use it, he said "no" and hung up.  Then he went to the restroom and dropped a man-sized load and didn't flush.

He's joking. It's true, 'Blast processing' is an aspect of how the MegaDrive/Genesis was engineered to let a frame be put together by the 68000 while the VDP drew the first. It was also a marketing gimmick to explain to the average Joe why a 7.67 MHz 68000 was faster than a 2.68 MHz (on average) 65c816 processor in the SNES.

And no, Tom Kilanske had no role in designing the MD's VDP. It was built based on the Sega Master System's VDP, which was based on the Texas Instruments part TMS9918. In fact he didn't work on the MegaDrive at all, because he joined Sega of America in 1990, and the MegaDrive was designed predominantly in Japan in the late 80s.

DUH!!!  that's the number 1 rule..

but you still failed to explain the:  how it was running in the first place..  if it was a static discharge, it would have fried it INSTANTLY...

There's such a thing as partial damage to an IC, partial and sporadic failure, and existing damage causing failure at a later time/date. It is also very possible you damaged a different component, such as a resistor or capacitor, or a portion of any of the system's many ICs. Without knowing your exact procedure and the environment in which you modified and operated your machine it's nearly impossible to know where and how the fault transpired.

[Joe Redifer]

And yes, my Pontiac did have a 68K as it's ECU controller.

Yes I know it did, but Tom Kilanski did not let Pontiac use Blast Processing because that feature was too advanced for the rest of the world.  Blast Processing would have rendered your Pontiac as the fastest car ever made, and Tom had a Ferarri and didn't want it to be outrun by your Pontiac.  Tom was not president of Sega when the 68000 was invented, so he traveled back in time to invent the 68000 beforehand and give it Blast Processing.  This is why the 68000 was the most advanced chip ever made... it used technology from the future.

[RobIvy64]

And yes, my Pontiac did have a 68K as it's ECU controller.

Yes I know it did, but Tom Kilanski did not let Pontiac use Blast Processing because that feature was too advanced for the rest of the world.  Blast Processing would have rendered your Pontiac as the fastest car ever made, and Tom had a Ferarri and didn't want it to be outrun by your Pontiac.  Tom was not president of Sega when the 68000 was invented, so he traveled back in time to invent the 68000 beforehand and give it Blast Processing.  This is why the 68000 was the most advanced chip ever made... it used technology from the future.

You are a very special and insightful person!

[blackevilweredragon]

Here's the environment it was modded in...

(but the Genesis is fine..  it's working NOW, I just beat Snatcher on it today)

79f Room Temperature  (Florida, not some ICE cold state where static discharge is a big worry)..  i was grounded too...
Done on an electronics lab table (with all the parts, oscilloscopes, multimeters, etc)

im not new to electronics, and don't appreciate being treated like a newb..  i've been doing this for years...

[Joe Redifer]

You are a very special and insightful person!

I'm just reporting the cold, hard facts.  It's all documented on Wikipedia, CNN, Fox News, the BBC (they did a television documentary about the time traveling escapades of Tom Kilanski), and even PBS.  

[Epicenter]

Here's the environment it was modded in...

(but the Genesis is fine..  it's working NOW, I just beat Snatcher on it today)

OK, so we know you damaged your 68000. We just don't know how. We probably won't ever know that, unfortunately. I'd really plug it back in and make sure it was connected properly. You said before it had a dry solder joint that prevented boot, and your socket looks a bit faulty. It has extra pins added with parts from another socket, so stability is a big concern.

79f Room Temperature  (Florida, not some ICE cold state where static discharge is a big worry)..  i was grounded too...

Temperature isn't the largest concern in buildup of a triboelectric charge that can cause ESD. It's humidity.

im not new to electronics, and don't appreciate being treated like a newb..  i've been doing this for years...

I didn't call you out on your post because of concern for your level of experience. I called you out because you were posting things that were blatantly false, and posed the danger of spreading invalid and harmful rumor to the modding community.

[GZeus]

Here's the environment it was modded in...

(but the Genesis is fine..  it's working NOW, I just beat Snatcher on it today)

79f Room Temperature  (Florida, not some ICE cold state where static discharge is a big worry)..  i was grounded too...
Done on an electronics lab table (with all the parts, oscilloscopes, multimeters, etc)

im not new to electronics, and don't appreciate being treated like a newb..  i've been doing this for years...

Dude, demonstrate some knoweldge and maybe we'll listen.

Just because you've been doing something for a long time doesn't mean you've been doing it WELL.
All that is: me pointing out a logical fallacy.

[blackevilweredragon]

but come on, an overclock can be dangerous..  i wasn't even getting an attack at you, notice my OP, remember I said that i read your disclaimers, and i wasn't mad..

but sometimes overclock CAN cause damage...

(and i mentioned florida, because the humidity was low that day, damned heat waves)

[blackevilweredragon]

ok, look guys, there's a slight possibility there's misinformation going on..

i've said it before, and i'll say it again (as much as i HATE saying it)..  my autism gets in the way of "explaining" things..  i know what i want to say, but i don't know HOW to say it..  (and the same autism made me better with hardware, software, and electronics overall, because of how my mind sees it)

[Epicenter]

I didn't claim you made any personal attack against me. My replies are purely factual response to incorrect technical information you posted.

Overclocking can cause damage .. in situations where the processor's temperature or voltage are out of operational spec. Neither of which are.

[GZeus]

im not one to talk?  fuck, i must be retarded to even have certifications in electronics....

my ceramic 68000 CPU gets to 96f at 7.6MHz...  i know how CPUs are made...  don't EVER doubt me, as I don't doubt you guys...

I doubt the hell out of the idea that you might be certified for DIGITAL electronics.
And your knoweldge of ANALOG signal mechanics is lacking as well.

You've advised people to run the various processors in their genesis to different speeds. Increasing the clock speed of the sound and video processors but leaving the main at PAL speed will cause 'tearing' on screen and sound dropouts.
And NO boost in performance.
Inverting that causes the same problems.

[blackevilweredragon]

ok, how about this..  is it possible that the 68000 in my Genesis was just on it's last leg?  and it was purely coincidence?

(because I had test equipment, and all said I did good, no discharge on the monitors, no shorts)

[RobIvy64]

ok, how about this..  is it possible that the 68000 in my Genesis was just on it's last leg?  and it was purely coincidence?

(because I had test equipment, and all said I did good, no discharge on the monitors, no shorts)

No. Something had to have happened during the overclocking procedure.

[blackevilweredragon]

im not one to talk?  fuck, i must be retarded to even have certifications in electronics....

my ceramic 68000 CPU gets to 96f at 7.6MHz...  i know how CPUs are made...  don't EVER doubt me, as I don't doubt you guys...

I doubt the hell out of the idea that you might be certified for DIGITAL electronics.
And your knoweldge of ANALOG signal mechanics is lacking as well.

You've advised people to run the various processors in their genesis to different speeds. Increasing the clock speed of the sound and video processors but leaving the main at PAL speed will cause 'tearing' on screen and sound dropouts.
And NO boost in performance.
Inverting that causes the same problems.

lacking?  all you do is copy and paste what other people say...  oh, and not to mention, bitch at Joe all the time, which is unfair to him, because he knows things too you know, he's just, weird, that's all...

"not to mention, what you JUST posted, made no sense at all"

[RobIvy64]

As Devon (Epicenter) stated above, there is simply no way to kill a 68000 by overclocking it (considering everything was installed correctly). I would state why, but I would just be echoing what has already been said.

[blackevilweredragon]

ok, how about this..  is it possible that the 68000 in my Genesis was just on it's last leg?  and it was purely coincidence?

(because I had test equipment, and all said I did good, no discharge on the monitors, no shorts)

No. Something had to have happened during the overclocking procedure.

well, im not going to explain the condition i did this overclock in..  it was a planned test..  we used equipment that made sure NOTHING got damaged..

during Genesis operation, the test equipment showed the temp rise fairly quickly, then the address lines ceased functioning...

[GZeus]

ok, look guys, there's a slight possibility there's misinformation going on..

i've said it before, and i'll say it again (as much as i HATE saying it)..  my autism gets in the way of "explaining" things..  i know what i want to say, but i don't know HOW to say it..  (and the same autism made me better with hardware, software, and electronics overall, because of how my mind sees it)

I'm mildly autistic.
This is NOT simply autism.
You're being an ass ON TOP OF it.

Instead of admitting "I don't know how to explain this, let me get some advice, i'll post later" you MAKE SHIT UP and expect us to swallow.

You're arrogant, egotistical AND autistic. The first two are treatable.
The third is largely listening.
Listen and read about what you want to explain. read it from 3 different sources. Once you have multiple viewponts, you'll likely be able to describe it on your own terms.


Also, autism doesn't IMPROVE certain skills. It FORCES you to learn other means of communicating/expression/entertainment because normal means don't work.

Simply put, you have alot to learn in many areas. memorization does not equal understanding.

[GZeus]

im not one to talk?  fuck, i must be retarded to even have certifications in electronics....

my ceramic 68000 CPU gets to 96f at 7.6MHz...  i know how CPUs are made...  don't EVER doubt me, as I don't doubt you guys...

I doubt the hell out of the idea that you might be certified for DIGITAL electronics.
And your knoweldge of ANALOG signal mechanics is lacking as well.

You've advised people to run the various processors in their genesis to different speeds. Increasing the clock speed of the sound and video processors but leaving the main at PAL speed will cause 'tearing' on screen and sound dropouts.
And NO boost in performance.
Inverting that causes the same problems.

lacking?  all you do is copy and paste what other people say...  oh, and not to mention, bitch at Joe all the time, which is unfair to him, because he knows things too you know, he's just, weird, that's all...

"not to mention, what you JUST posted, made no sense at all"

Joe's an ass.
I can';t think of a time he wasn't being snotty or sarcastic.

[Epicenter]

How were you checking all the address lines? Do you have an online 68000 debugger? I doubt this. Interference from test equipment could have introduced unknown factors and in some way led to the failure.

At any rate, how hot WAS it? If it wasn't hot enough to burn you, it should've continued to chug along. I've operated my desktop processors at temperatures hotter than what is required to boil water without incident. They continued working flawlessly, with no visible errors, in very strenuous tasks. When I say my 68000 operates superbly at 25.4 MHz, that is to say, 331% NORMAL SPEED, it casts severe doubt on the concept of your chip dying of catastrophic overheating at a mere 13.4 MHz, or 174%.

[GZeus]

ok, how about this..  is it possible that the 68000 in my Genesis was just on it's last leg?  and it was purely coincidence?

(because I had test equipment, and all said I did good, no discharge on the monitors, no shorts)

No. Something had to have happened during the overclocking procedure.

well, im not going to explain the condition i did this overclock in..  it was a planned test..  we used equipment that made sure NOTHING got damaged..

during Genesis operation, the test equipment showed the temp rise fairly quickly, then the address lines ceased functioning...

All possible causes of damage have been laid out.
Deductive reasoning proves that YOU are the cause.

[blackevilweredragon]

shut the hell up GZeus, you know why most call you a troll? because all you do is repeat what others say, and make yourself look better..

And Joe isn't an ass..  he knows what he's saying too..  i mean, you alone think the Genesis has a 30Hz refresh rate...

[NFG]

Sorry guys, I'm gonna lock this while some people take a time out.

We're all after the same goals here and I'd prefer a more supportive atmosphere.

[update]  By request this thread will not be reopened.