Do you by any chance have the pinout spec for these sockets? I am more interested in PLCC-28, actually, for 22V10s

Thanks

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In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

I feel embarrassed... I could've done that myself but was too lazy after spending what felt like an hour on octopart... I thought you probably have a specsheet somewhere. Thank you.

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In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

Good news!

It is feasible to 3d-print your own wire-wrap sockets.

As previously discussed, wire-wrap sockets have gotten expensive and hard to get, especially when it comes to PLCCs. But for those of us with inexpensive (mine was under $200) 3D-printers, there is another option: print your own socket. Here is a picture of my early experiments:

Shown: a few DIP sockets, a pinned ̶P̶L̶C̶C̶-̶2̶8̶ PGA-28 socket (all but last pin, shown next to it), and an unpinned P̶L̶C̶C̶-̶2̶8̶PGA-28 socket.

_________________
In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

I've spent the last couple of weeks blowing my mind and really trying to figure out how circuits work. It's amazing how incredibly ignorant I've been all my life! You did try to straighten out my primitive thinking, but what really did it was watching Rick Hartley's videos, in particular 'How to Achieve Proper Grounding' https://www.youtube.com/watch?v=ySuUZEjARPY. But all of his videos are extremely enlightening, and unlike many youtubers he does not waste your time with self-aggrandizing crap.

The most important points I wish I had understood earlier:

• Clock speed is irrelevant; frequencies implied by rise time decide the 'speed' of the circuit. These are pre-decided by the chips used; the clock only triggers your high-speed circuit every so often.
• Energy in a circuit is not in the copper wiring; it is a field in the dielectric substrate between the conductor and the lowest-impedance return. The copper acts as a waveguide, directing the flow of energy along a path.
• Controlling impedance.. capacitance and inductance of interconnects at different frequencies, etc,
• Plan the return path - it is at least as important as the forward path, and may bite you if an unexpected lower impedance path exists (such as a nearby signal or power conductor)

I feel enlightened and horrified. I've been blindly playing 'connect-the-dots' in my PCB design, with a vague understanding that somehow a 'good ground' was important. I can see now that many of my signal tracks with no obvious returns created ridiculous fields that coupled to everything in their way to the nearest low-impedance return path. And I see why having a ground-plane is a pretty good idea, and why copper pours are not at all a substitute. I thank everyone who tried to tell me...

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In theory, there is no difference between theory and practice. In practice, there is. ...Jan van de Snepscheut

Thanks for the pointer!

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

I don't know if automotive technology is an appropriate branch of this discussion, but in my decades of experience with engine control systems I have found that a "dirty" or "noisy" VDD can be just as vexing as a "dirty" or "noisy" VSS. I don't design PCBs, but if I did I would treat them with equal significance wherever and whenever possible.

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Got a kilobyte lying fallow in your 65xx's memory map? Sprinkle some VTL02C on it and see how it grows on you!

Mike B. (about me) (learning how to github)

I used autorouter extensively. My designs were always 2-layer PCB up til few months ago. My 2-layer design approach is reducing board outline by 0.05" all around and bring out several power/ground pads to the edge of the reduced board outline; run the autorouter and then increase the board outline by 0.05" and manually route 0.025" power and ground traces connecting to the edge power/ground pads. This is an easy way to provide multiple ground returns.

W65C02/816 plus fast RAM are noisy combination. for 4"x4" size boards with W65C02 & RAM I'm gravitating toward 4-layer pc board. I've also found dynamic RAM can be quite noisy so I'm now migrating my designs with DRAM memories to 4-layer PCB.
Bill

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Just to elaborate on Garth's post above and his second paragraph here ...

Because making PCB traces traces wider does not significantly reduce their inductance, even thin traces are acceptable for creating a grid of ground traces (as an approximation of an actual ground plane). And thin traces mean such a grid needn't add significant area to the board.

Neither would the grid complicate the routing much. Regarding signal wiring, it's generally true that north-south traces tend to go on one side of the board and east-west traces on the other. And the ground grid can "go with the flow" of whatever else is there, interleaving its north-south ground traces with north-south signal traces, and likewise for east-west.

At every point where a N-S ground trace crosses an E-W ground trace you'll want to connect the two (otherwise the grid doesn't approximate a plane -- current must be able to flow N-S, E-W or in a zigzag for diagonal travel). And if the N-S and E-W ground traces are on opposite sides of the board then you'll need to use a via to connect them. Vias do add a bit of inductance, but hardly enough to negate the benefit of the grid.

I'm not advocating grids as the answer to every situation. But they certainly bear consideration as one useful option on the continuum between outright rats-nests and rigorous, controlled-impedance designs. As a moderately interesting data point, it's worth noting that portions of my 1988 KK Computer use 74AC series logic running at 80 MHz. KK is implemented in wire-wrap, and there's no ground plane. But there is a ground grid, which in this case means almost every IC has four connections (N, S, E and W) emanating from its Gnd pin to those of its neighbors. (Also, almost every IC's Gnd pin has a bypass cap running directy to the IC's Vcc pin, just as Garth suggested in the linked post).

-- Jeff

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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?