Vaguely reminiscent of 2 famous lines from an old movie...
- I come in peace !
- You go in pieces!
Man, this dates back to 1990. Am I really that old ? Looks like I am...
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Vaguely reminiscent of 2 famous lines from an old movie...
Saruman-64 and Saruman-TED are both ready for you. Since you have a Plus/4, I would suggest Saruman-TED with no switch.Gyro Gearloose wrote: ↑Sun Jan 19, 2020 9:23 pm I cleverly avoided the C16 RAM issue by buying a Plus 4. Boy am I smart. I wonder if one day I'll be able to put something useful instead of the built-in crap.
My approach, when something doesn't work the way I expect is to check every possibility and every possibly implicated signal... everyone of them.
Yes, everyone else but not the original datasheet...
It can be working because it is not your original design but the V1.4 "Christmas patched " version with the OR gate that ONLY on WRITE shorten the /CAS signal with PH0 CLOCK line... Sometimes people lose the opportunities to be silent...
Well, unlike you, I learn from my mistakes... you still sell VIC-20 expansions that can wreck VIC-20 cart port connectors.
If you think it can't have a decent read timing then you don't know how these components interact. I suggest you check using something like Microcap. https://www.spectrum-soft.com/demo.shtmDo you think that your new schematics with trigger inverters (didn't have to be with XNOR?) will be working?
amaze us! realize it and public the results!
(it can't have a decent READ timing...)
Hey! Looks like I'm a member of a select club!There is a user called MCes on the Plus4World forum. I have noticed before that he is quite aggressive. He has developed some hardware for the C16/Plus4 and attacks anyone who he sees as a rival.
eslapion wrote: ↑Mon Jan 20, 2020 10:39 am Just got this e-mail:Hey! Looks like I'm a member of a select club!There is a user called MCes on the Plus4World forum. I have noticed before that he is quite aggressive. He has developed some hardware for the C16/Plus4 and attacks anyone who he sees as a rival.
Now is more clear which kind of person I am, and which kind of person he is.Hi (XX),
yes, i seen the payment.
Originally Posted by (XX)
"I could addvertise those in Facebook group"
I am an old-style man, and I will explain what....
In the same days that I was waiting for the PCBoards of this project Mr. (YY) shows on Facebook its "(ZZ)" that's an internal expansion with same functionality of mine (...).
I and (YY) had message contacts and I decided that I will not present my expansion on Facebook (where (YY) was starting before) but my project is available via Ebay, Amibay, and some technical forum.
I consider this as respect of others work (some others use an opposite comportment with me, but I'm happy to be different to some people...).
I use the money gained with this hobby to realize the next project, not for living.
So I invite you, on public facebook post, to not write about my expansion.
(...).
Thanks for comprension
(MCes)
There you go...
Yeah but the threshold level for TTL/NMOS devices is 1.3V so the data is still valid. You're not indicating the value of your added resistor and you're not showing what happens when the value of D0 happens to be a logic 0. This brings the question: What impedance loading will render the data unreadable? Is this an impedance load you can reasonably find in a Commodore 8 bit computer ? I suspect not.so I made a little test: a resistor was placed from Data0 to ground for intercept a my doubt,
and this is the result.....
...
And voilà!
The CPU work as spec (or less too): At /CAS rising edge the CPU is not driving its data pins ( pins= high impedance) and the voltage remain on floating PCB traces (and leakage capacitance) until other devices will get the BUS, so on rising edge of /CAS a "floating" data will be captured.
Any kind of noise can destroy the information stored in a "not feeded" bus, also something that is from the cartridge connector...
Do I need to add anything else?
Oh yes... IMMATURE!Oh yes:
GOOD LUCK!