Re: A new generation of PLA for the C64 is now available.
Posted: Thu Jun 08, 2017 8:33 pm
Why? Have I said something bad about your products? Or have I been badmouthing your electronics skills or knowledge? Or your soldering procedures?
Or maybe I have been spreading around rumors about your product not based on any facts?
I think I'm the one that should be pissed!
My choice of using a regulator may steal 6 mA of current, but for that I get steady voltage that does not fluctuate with input voltage or current the CPLD is using, like a plain resistor and a diode does. With this 6 mA I also get protection for the CPLD for overvoltage that using original C64 power supply may cause (yes, there are still people using original power supplies!), and a protection for inserting PLA accidently to a SID socket.eslapion wrote: For one thing, a voltage regulator, to me, is an indicator of lack of knowledge in electronics. It's just extra parts to impress gullible people.
And raising voltage with resistor on ground pin isn't a "hack" if that was what you were trying to say earlier... it's perfectly valid method described in regulator's datasheet.
My goal was 25ns based on my measurements on 906114-01. And to achieve that I chose 5ns version over 10ns, because using 5ns "blocks" would get me exactly to my goal (5x5ns -> 25ns) insteadeslapion wrote: For another, this '5ns for accurate' thing is major horse manure - genuine Commodore PLAs themselves have enormous response speed discrepancies; from 24 to 38ns - a 60% variation.
of using 10ns "blocks" that would have got me into either 20ns or 30ns (2x10ns or 3x10ns) delay. After receiving the parts I found out that there is a lot more things involved with
the timing, but nevertheless the same principle stays. Using a faster chip enables you to use shorter "building blocks" and thus getting more accurately to your goal.
I agree that it's pretty close to the rearest original PLA - 251064-01.eslapion wrote: Third, PLAnkton is correctly delayed on all outputs. CASRAM requires more but otherwise, the low power mode and slew rate limiters do all that's needed.
I had already ordered new PCBs (with pads new parts) ordered when I shipped the J-PLA to e5frog (before any of your comments about J-PLA), I also mentioned that to him (you can check that from him).eslapion wrote: Last but not least, the latest 'incarnation' of J-PLA suddenly have new parts added on the underside. Apparently a result of me posting more technical information here. If emulation is the sincerest form of flattery then I could definitely do without this one...
The extra parts are added resistor and capacitor like new C64's have (C204 and R42), that can be enabled. Possibly not needed (because of extra delay in #CASRAM inside CPLD) and not enabled by default, but they exists there now incase somebody finds a C64 that needs them.
I did not "emulate" that from you, I put these components after the CPLD output, like the original C64 has after the PLA. Not in middle of two CPLD signals.
The facts needed to create J-PLA did not come from your or from your posts. The facts needed have been around from the 90's, the exact same information that you used. Your posts don't add any technical information that wasn't available before. Even the CPLD based implementations existed before, you weren't the first one and can't take the credit of that. I did select the same CPLD, that's true, but not for the reason of copying you but only for the reason it seemed like a good alternative. I didn't use any VHLD's found on the net, as using them wouldn't have got me to my goal with the timings. Not even if I would have used 10ns version in low power mode & slow slew rate mode. I made my own VHLD based on the logic equations available on the internet, but made much simplified code (but keeping the logic 100% same) with the stuff needed for the extra delay.eslapion wrote: J-PLA exists because I posted the necessary technical information online on Melon64 nearly 2 years ago. Of course, Mr. Schönfeld and his friends dismissed all that as lunacy coming from Neptune. All Janilaa managed to prove is that he won't so quickly disregard information coming from outside the officially accepted views of the 'Old Boys Club'. He just grabbed information fetched through the hard work of other people and uses it to make his own amateurish replica.
You really should stop guessing things as your bad at it! I would appreciate you asking me if you don't know something, before making guesses and representing these guesses as facts!eslapion wrote: Even the solders are inconsistent because they are made one at a time with an ordinary soldering iron using normal soldering procedures. No wave or drag soldering with professional methods and products.
I'm using solder paste and hot air rework-station. I'm not using a stencil, so I get occasionally solder bridges between legs, which I the fix with a regular soldering iron. That's how the spike may have formed. I really didn't realise that this was a beauty competition? I thought that it would be enough that all the legs are soldered firmly to the pads...
I assume you have some REAL evidence for that argument?eslapion wrote: Counterfeit IC rated for 5ns.
You may have just found out the reason they were cheaper!eslapion wrote: Manufacture date is 1309 - this chip is 4 years old!!
Old stocks might have been sold to a smaller dealer for discounted price.
Check out the following picture...eslapion wrote: Typeface is smaller and very difficult to read; this photo had to be taken with more lighting and longer exposure.
On the left is a genuine 5ns XC9536XL bought from Digikey and on the right is a 10ns version also bought from Digikey.
The one on left been soldered and after that cleaned with IPA. Cleaning makes the text much harder to read as you see.
Both were originally exactly the same. I don't have any unsoldered 5ns CPLD's right now, but I can assure that they looked exactly same.
Don't get excited about the 10ns version on J-PLA PCB, I'm not still going to use those but I did order some to make some tests.
Also notice the difference in typeface and the logo when compared to your 10ns chip.
My genuine CPLD's have a lot thicker letter I's on the logo. Also the logo is different size, on my sample the registered trademark symbol is
at the second pin from the right in upper row and in yours it's on the third pin. Also the R-symbol is different size.
Our genuine 10ns chips bought from the same distributor have that much differences with
only 4 weeks difference in manufacturing date, imagine how much differences there can be in 4 years.
Even if the CPLD's I can prove to be genuine are that much different from yours, I ain't claiming your
chips counterfeits as I know that there are different plants in different countries manufacturing the same
GENUINE chips and some variation in markings can exist.
And once again for the audience, only few of the first CPLD's on J-PLA were bought from China (which doesn't automatically mean they are counterfeits).
I can't prove them to be genuine (and neither can eslapion prove them not to be genuine), but they have exactly same electrical characteristics and
functionality as the originals and that's why I believe them to be genuine. If any of the those first CPLDs would happen to fail, I'm more than happy to replace those to a J-PLA's with CPLD's I know to be genuine.
The one seen on the left above is the one I'm using currently and have been using for some time already and will use
these in all J-PLA's in the future. I guarantee these to be genuine and purchased from Digikey, which is large authorized distributor for Xilinx.