....yet MORE things for me to buy and play with!! 😀😀😀 I imagine that controller card will follow in quick order, so will bide my time before raiding your tindie store again!
Thanks for your continued support. It’s really appreciated! I’m looking forward to sharing my CreatiVision Controller with others, who might also enjoy it like I have. Be sure to note my “Follow-up” (in the Blog). Specifically, that the NMI button may not have been absolutely necessary (for the CreatiVision project), however it does implement “exact hardware re-creation”, to help ensure compatibility with all CreatiVision software.
@@DigicoolThings Well, this is the exciting thing - I'm perfectly aware of how ahead of myself I am on this, but I already have visions of recreating my original computer I had growing up, recreating a pin compatible bus that should accept the original cards - something this project lends itself very well to. I also imagine my proposed Atari 2600 recreation would benefit from the controller card you have, and I imagine any number of other potential 8-bit system recreations will benefit just the same, including mine! I think you've struck a perfect chord with this MECB project...
Thanks. You ask a very observant question! 🤓 The reason is that I wanted enough space around the PLD to allow for a ZIF socket, which also limited locations for a bypass capacitor in close proximity to the power pins. I further considered that six bypass capacitors was sufficient for the board’s devices, with them all located as close to individual device power pins, as reasonable. The lack of an additional bypass for the PLD has not caused any issues, and power line noise levels appear acceptable on the scope.
@@DigicoolThings If using a socket for the IC you can place a SMD cap under it. saving space, sometimes do it with TPH caps as well as 100n's are quite small and will fit under the socket.
@@TheEmbeddedHobbyist Good suggestion. Although, I'm a bit of a neat freak (perhaps a little OCD?), so I probably wouldn't like the resulting requirement to use an IC socket, and to probably bend the Cap over to lie on it's side! LOL The main issue for me was to ensure that during typical operation, the noise level seen on the PLD power pins was within acceptable levels. Of course, you can never have too many bypass capacitors! 🤓
@@DigicoolThings Sometimes quite hard to capture those nasty little spikes on the scope. those hungry little chips take gulps when you least expect it . 🙂
@@TheEmbeddedHobbyist Indeed, a fair comment. Certainly, my testing methodology wouldn’t be adequate for a consumer product, but for my hobbyist / maker experimental use, it has (so far), proven to provide an acceptable level of reliability. 🤔
Was there no spare pins with interrupt function that you could have used? Tend to think of the NMI as the last ditch interrupt, as the bugger has you my the balls as, as the NMI states you can't mask it out if you don't want to be interrupted. Can break the disabling of interrupts to make a function atomic. not that in playing games you need atomic functions. Now i can feel the old grey cells going back to sleep. 🙂
Note that I'm using NMI to replicate the original CreatiVision design (which used NMI for it's Reset button). So, it wasn't really my choice to use this approach, but I figured an NMI button may well be useful for compatibility with other applications that may also use NMI for a "soft" Reset, which I believe NMI was often used for.
@@DigicoolThings Well as it can't be masked a software reset as a good use for it. Normally I'd save it for errors that need instant attention. But if that's what they did who are we to say different. 🙂
....yet MORE things for me to buy and play with!! 😀😀😀 I imagine that controller card will follow in quick order, so will bide my time before raiding your tindie store again!
Thanks for your continued support. It’s really appreciated! I’m looking forward to sharing my CreatiVision Controller with others, who might also enjoy it like I have.
Be sure to note my “Follow-up” (in the Blog). Specifically, that the NMI button may not have been absolutely necessary (for the CreatiVision project), however it does implement “exact hardware re-creation”, to help ensure compatibility with all CreatiVision software.
@@DigicoolThings Well, this is the exciting thing - I'm perfectly aware of how ahead of myself I am on this, but I already have visions of recreating my original computer I had growing up, recreating a pin compatible bus that should accept the original cards - something this project lends itself very well to. I also imagine my proposed Atari 2600 recreation would benefit from the controller card you have, and I imagine any number of other potential 8-bit system recreations will benefit just the same, including mine! I think you've struck a perfect chord with this MECB project...
Nice video, thanks :)
@@RixtronixLAB Thanks for feedback. 🤓
Cool. How come the glue login chip doesn't have a decoupling cap?
Thanks. You ask a very observant question! 🤓 The reason is that I wanted enough space around the PLD to allow for a ZIF socket, which also limited locations for a bypass capacitor in close proximity to the power pins. I further considered that six bypass capacitors was sufficient for the board’s devices, with them all located as close to individual device power pins, as reasonable. The lack of an additional bypass for the PLD has not caused any issues, and power line noise levels appear acceptable on the scope.
@@DigicoolThings If using a socket for the IC you can place a SMD cap under it. saving space, sometimes do it with TPH caps as well as 100n's are quite small and will fit under the socket.
@@TheEmbeddedHobbyist Good suggestion. Although, I'm a bit of a neat freak (perhaps a little OCD?), so I probably wouldn't like the resulting requirement to use an IC socket, and to probably bend the Cap over to lie on it's side! LOL The main issue for me was to ensure that during typical operation, the noise level seen on the PLD power pins was within acceptable levels. Of course, you can never have too many bypass capacitors! 🤓
@@DigicoolThings Sometimes quite hard to capture those nasty little spikes on the scope. those hungry little chips take gulps when you least expect it . 🙂
@@TheEmbeddedHobbyist Indeed, a fair comment. Certainly, my testing methodology wouldn’t be adequate for a consumer product, but for my hobbyist / maker experimental use, it has (so far), proven to provide an acceptable level of reliability. 🤔
Was there no spare pins with interrupt function that you could have used?
Tend to think of the NMI as the last ditch interrupt, as the bugger has you my the balls as, as the NMI states you can't mask it out if you don't want to be interrupted.
Can break the disabling of interrupts to make a function atomic. not that in playing games you need atomic functions.
Now i can feel the old grey cells going back to sleep. 🙂
Note that I'm using NMI to replicate the original CreatiVision design (which used NMI for it's Reset button). So, it wasn't really my choice to use this approach, but I figured an NMI button may well be useful for compatibility with other applications that may also use NMI for a "soft" Reset, which I believe NMI was often used for.
@@DigicoolThings Well as it can't be masked a software reset as a good use for it. Normally I'd save it for errors that need instant attention. But if that's what they did who are we to say different. 🙂