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Re: [WDC65C02] STA writing when it feels like it?
Posted: Thu Jul 08, 2021 8:13 pm
by ThisWayUp
Want to give the chap a moment to breath
That's amazing
would never have thought such an old CPU had still a so active community
I just made myself a 5v power supply from a USB cable like suggested by BigEd and ThisWayUp and well, things are looking much better! I'm having a really consistent flow of instructions running now !
Seems like the 5v given by the Arduino were indeed the root cause of the problems.
I'll keep you posted if things go south again but works like a charm right now.
but I am also seeing a lack of decoupling capacitors.
I read about those capacitors but indeed didn't put any on my setup. I guess I will put them on as well
A big thank to all of you guys
Awesome! The devil/gremlin is most often in the details. It's a constant struggle.
Re: [WDC65C02] STA writing when it feels like it?
Posted: Fri Jul 09, 2021 5:52 am
by BigDumbDinosaur
Having seen a few of the Ben Eater videos and watched them from the perspective of someone who has a lot of experience with digital circuits—and the 65xx family, I wish those who watch those videos and then get the urge to build a 6502 machine first read Garth's tutorial in its entirety. Mr. Eater is skipping over details that may make the difference between a machine that computes and one that is DOA. I think the problems that Doko encountered likely would not have occurred if he had been given more detail in the videos he watched.
Re: [WDC65C02] STA writing when it feels like it?
Posted: Fri Jul 09, 2021 5:57 am
by BigDumbDinosaur
Want to give the chap a moment to breath
That's amazing
would never have thought such an old CPU had still a so active community
Just so you know, the 65C02 (the CMOS version of the 6502) is readily available from electronics distributors. The design may be old, but it is also current, being used in all sorts of applications that you can't imagine. It has been estimated over 100 million per year are produced and shipped in one form or another. For example, the 65C02 is used in implanted medical devices, such as pacers and defibrillators. Someone you know may well be "powered" by a 65C02.
Re: [WDC65C02] STA writing when it feels like it?
Posted: Fri Jul 09, 2021 7:07 am
by Doko
first read Garth's tutorial in its entirety.
Where can I find this tutorial?
Someone you know may well be "powered" by a 65C02.
Actually I know Bender is
Re: [WDC65C02] STA writing when it feels like it?
Posted: Fri Jul 09, 2021 7:28 am
by GARTHWILSON
first read Garth's tutorial in its entirety.
Where can I find this tutorial?
http://wilsonminesco.com/6502primer/
It was written to answer questions and problems that kept coming up on the forum, and I keep making improvements to it; in fact, I made a few minor changes and added a link just yesterday, and should receive some information for another improvement in the next day or two. It's in 22 logically organized sections covering the various aspects of designing, building, debugging, and programming your own 6502 computer, and the last section, "circuit potpourri," gives lots of ideas for interfacing lots of things. It's mostly about hardware but does have some software tips and what to put in your source code. I encourage you to go through the sections in order.
The 65c02 is still going into automotive, appliance, toy, and industrial equipment. Until recently, it had been going into in-body implantable electronics too like defibrillators; but I have not been able to find out if it still is. Apparently it was, for many years, the only processor approved for that kind of thing.
Re: [WDC65C02] STA writing when it feels like it?
Posted: Fri Jul 09, 2021 7:30 am
by jfoucher
Where can I find this tutorial?
There you go:
http://wilsonminesco.com/6502primer/
Edit: You beat me to it Garth but I’m leaving it up anyway
Re: [WDC65C02] STA writing when it feels like it?
Posted: Fri Jul 09, 2021 10:26 am
by fredericsegard
Having seen a few of the Ben Eater videos and watched them from the perspective of someone who has a lot of experience with digital circuits—and the 65xx family, I wish those who watch those videos and then get the urge to build a 6502 machine first read Garth's tutorial in its entirety. Mr. Eater is skipping over details that may make the difference between a machine that computes and one that is DOA.
Having been initially inspired by Ben Eater videos also, I researched the 6502 as much as I could before I assembled the parts together. Those videos reminded me of my 6809 days at school some thirty years ago... Ahhh, the nostalgia bug. But in my research, I came across Garth's primer which was invaluable. Thanks Garth, for sharing your expertise!
My build may need some more tweaking, but it's getting there. I'm actually up for a second read-through as a refresher before tackling version 2:
viewtopic.php?f=4&t=6681