#NAND gate

[jhnn2varra]

https://www.futureelectronics.com/p/semiconductors--memory--storage--embedded-storage/emmc04g-m627-e02u-kingston-8130398

eMMC storage drives, emmc storage upgrade, eMMC multimedia cards

4GB eMMC v5.1 3.3V 153-ball BGA Operating Temp - 25C to +85C

[mrvaxxl]

Logic Gates (NOT, Buffer, AND, OR, NAND, NOR, XOR, XNOR) and Their Truth Tables

Logic gates are the cornerstone of digital electronics, serving as the fundamental building blocks for a vast array of electronic devices and computing systems.

Each gate, characterized by a unique symbol, performs a specific logical function, dictating how binary inputs are processed to produce a binary output.

Understanding the symbols and truth tables of various logic gates, such as AND, OR, NOT, NAND, NOR, XOR, and XNOR, is crucial for anyone diving into the realms of circuit design and digital computation.

Read more:

[mich2guezz]

74 A/HC/T Series Logic Chips, Types of 74 A/HC/T Series Logic Chips

74HC Series 6 V Dual Retriggerable Monostable Multivibrator with Reset - TSSOP16

[tgemorbingpaper]

imagigne two freaks. im talking two twisted fucking cycle paths,. twoof the worst guys youll ever encounter. now imagine that they r both autistic. and in love;. and t4t also

[jackoshadows]

The official website of Nand to Tetris courses

Came across this website and it’s such a helpful learning aid. I wish such websites existed back in the day when I was learning microprocessors and logic gates.

[hnry2kkrr]

https://www.futureelectronics.com/p/semiconductors--memory--storage--embedded-storage/emmc04g-w627-x03u-kingston-1111540

What is eMMC storage, eMMC memory, solid-state hard drives

EMMC04G-MT32-01G10

[rich2flirs]

Op amp comparator applications, Digital logic gate, hardware electronic device

LM2903 Series 36 V 250 nA SMT Dual Low Power Voltage Comparator - SOIC-8

[rymnd2liso]

Comparator applications, NOR gate indicate, Comparator circuit, NAND gates

LM2903 Series 36 V 250 nA SMT Dual Low Power Voltage Comparator - SOIC-8

[wlshy2ant]

What is 74HC series, Nova7400 quad 2-input NAND gate, d flip flop

74HC Series 6 V Dual Retriggerable Monostable Multivibrator with Reset - TSSOP16

[scarcelyodd]

"On the ground below, colors in the phalanx began to shift and move. Complicated and detailed circuit patterns appeared and gradually filled the entire formation. Ten minutes later the army had made a thirty-six kilometer square computer motherboard.

Von Neumann pointed to the gigantic human circuit below the pyramid and began to explain, 'Your Imperial Majesty, we have named this computer Qin I. Look, there in the center is the CPU, the core computing component, formed from your five best divisions. By referencing this diagram, you can locate the adders, registers, and stack memory. The part around it that looks highly regular is the memory. When we built that part, we found that we didn't have enough soldiers. But luckily, the work done by the elements in this component is the simplest, so we trained each soldier to hold more colored flags. Each man can now complete the work that initially required twenty men. This allowed us to increase the memory capacity to meet the minimum requirements for running the Qin 1.0 operating system. Observe also the open passage that runs through the entire formation, and the light cavalry waiting for orders in that passage. That's the system bus, responsible for transmitting information between the components of the whole system.

'The bus architecture is a great invention. New plug-in components, which can be made from up to ten divisions, can quickly be added to the main operation bus. This allows Qin I's hardware to be easily expanded and upgraded. Look further still - you might have to use the telescope for this - and there's the external storage, which we call the 'hard drive' at Copernicus's suggestion. It's formed by three million soldiers with more education than most. When you buried all those scholars alive after you unified China, it's a good thing you saved these ones! Each of them holds a pen and a notepad, and they're responsible for recording the results of the calculations. Of course, the bulk of their work is to act as virtual memory and store intermediate calculation results. They're the bottleneck for the speed of computation. And, finally, the part that's closest to us is the display. It's capable of showing us in real time the most important parameters of the computation.'"

- from Cixin Liu's The Three-Body Problem, translated by Ken Liu

[commodorez]

Thy Graphics

A graphics card for the Cactus directly patterned after the OSI-440, with a few modernizations and optimizations.

I've replaced the eight 2102 SRAM chips with a pair of 2114s. I've also swapped the 2513 character generator ROM with a 2816 EEPROM which gives me not only lower case letters, but pseudo-graphical characters not unlike PETSCII. I've re-implemented the address select logic using modern parts (thank you 74688), and swapped the open-collector NAND gate based video/sync combiner circuit with one I copied from a PET video combiner circuit using 4066 analog switches. I didn't like how vague the delay taps were described, so I added in some jumpers to let the user pick their delay timing.

And hooo boy this had some motherfucking BUGS in it.

Vertical sync polarity was backwards.

Video pixel data was inverted too.

In fact, so were the DIP switches for the address select.

I also got half of the 74123 resistor/capacitor inputs backwards due to not paying attention to the idiosyncrasies of the symbols in my old version of KiCAD.

Oh, and the character ROM I stole from my OSI-540B replica has inverted bit order, so the characters looked backwards.

Every single problem I had was due to something being backwards.

Nothing a little debugging can't fix. Took about 7 hours of tired stumbling with help from friends in the retrotech crew to figure out all the little faults and work around them, but in the end...

It works! It fucking works! The Cactus has video! I made a fucking video card from scratch! I didn't use any dedicated video chipsets or FPGAs or microcontrollers or CRTCs or any of that shit. I didn't make VGA, I made composite video.

All 24x24 usable characters on screen in monochrome goodness from this tiny little PCB. Now onto the Rev B design!

[srhe203]

kumie speaking

Me learning how to make NAND gates vs whatever saucy gif sets ppl are reblogging on here of an atm getting bashed open with a base ball bat

over

[moose-mousse]

What is half-adder and full-adder combinational circuits?

So this question came up in the codeblr discord server, and I thought I would share my answer here too :3

First, a combinational circuit simply means a circuit where the outputs only depends on its input. ( combinational means "Combine" as in, combining the inputs to give some output )

It is a bit like a pure function. It is opposed to circuits like latches which remembers 1 bit. Their output depends on their inputs AND their state.

These circuits can be shown via their logic gates, or truth tables. I will explain using only words and the circuits, but you can look up the truth tablet for each of the circuits I talk about to help understand.

Ok, so an in the case of electronics is a circuit made with logic gates ( I... assume you know what they are... Otherwise ask and I can explain them too ) that adds 2 binary numbers, each which have only 1 character. 

So one number is 1 or 0

And the other number is 1 or 0

So the possible outputs are are 0, 1 and 2.

Since you can only express from 0 to 1 with one binary number, and 0 to 3 with 2, we need to output 2 binary numbers to give the answer. So the output is 2 binary numbers

00 = 0

01 = 1

10 = 2

11 = 3 // This can never happen with a half adder. The max possible result is 2

Each character will be represented with a wire, and a wire is a 0 if it is low voltage (usually ground, or 0 volts) and a 1 if it is high voltage (Voltage depends. Can be 5 volts, 3.3, 12  or something else. )

BUT if you only use half adders, you can ONLY add 2 single character binary numbers together. Never more.

If you want to add more together, you need a full adder. This takes 3 single character binary numbers, and adds them and outputs a single 2 character number.

This means it have 3 inputs and 2 outputs.

We have 2 outputs because we need to give a result that is 0, 1, 2 or 3

Same binary as before, except now we CAN get a 11 (which is 3)

And we can chain full adders together to count as many inputs as we want.

So why ever use a half adder? Well, every logic gate cirquit can be made of NAND (Not and) gates, so we usually compare complexity in how many NAND gates it would take to make a circuit. More NAND gates needed means the circuit is slower and more expensive to make.

A half adder takes 5 NAND gates to make

A full adder takes 9 NAND gates.

So only use a full adder if you need one.

Geeks for Geeks have a page for each of the most normal basic cirquits:

I hope that made sense, and was useful :3

[sexhaver]

NAND Gate is a beautiful name for a baby girl

[szhmidty]

Kinda distressing that NAND and NOR are the universal logic gates but neither has an identity so you can't construct a nice algebra with them.

[sambhavami]

The Lost Flute - Part 1 (An Open Door)

Balarama's chariot kicked up the dust on the rustic road as it rustled past the sun-soaked fields and bristling bushes of Mathura's countryside. The sun was already about to kiss the horizon. His arms were wrapped around the half-asleep young girl beside him. She had covered her mouth with the end of her dress, her head resting on Balarama's shoulders. This journey had been long overdue, but it was finally drawing to a close.

"Can I ask you a question, Rama?" The girl asked quietly.

"You know you don't need my permission, Subhadre." Balarama smiled down at her.

Subhadra laughed quietly, "Rama, I've always heard how great of a flautist Kanha is, but I've never seen him play. He always makes excuses when I ask. Did he not enjoy playing the flute?"

Balarama shifted slightly in his seat, "Who told you that? He and that flute used to be inseparable. We wouldn't be able to pry it from his sleeping hands!" He chuckled at the memory.

"So why doesn't he play now?" Subhadra asked.

"I don't know Bhadre, maybe he's just too busy to be indulging in a hobby right now."

"Is that why he didn't come with us today?"

"Probably." Balarama sighed.

Suddenly, he sat up in his seat, "Look, there's our Vrindavan! Do you see those stone houses across the horizon? That's the village! And to the west, those are the pastures. From sunrise to sunset, that is where we lived! Nand-baba used to teach us every day- in the morning follow the sun but when he sets, you turn and run! I must tell you the stories about the times we got lost in the forests and nearly forgot that little poem!"

Balarama stood up from the cushioned seat of the chariot and started waving frantically at a man across the field, "Hey Madhu, MADHU!" He jumped down from the slowing chariot and ran towards him. Soon, a crowd gathered around them. A few boys ran back to the village to announce their arrival. The farmers and the gopas stood with folded hands as Balarama went around inquiring about their lives. 

As some villagers approached them carrying on torched, Balarama turned to Subhadra with a broad smile, "Come on then! We can walk the rest of the way!"

Balarama stopped and turned as the torchbearers fell a few steps behind. Subhadra was approaching him with her bejewelled skirt held high as she trod carefully on the muddy, uneven road as five villagers attempted to light the way as best they could. He laughed, "I probably should have told you to wear a lighter dress!"

"Well," Subhadra raised an eyebrow, "You did say I was going to meet two of the most important people of your life. You can't fault me for trying to impress!" Though her tone was soaked in sarcasm, she smiled warmly.

Balarama smiled back as he took a torch from one of the villagers, "Come on, walk with me!" He said as he put an arm around her.

---

Standing at the gates of the stone villa, Balarama looked around. There was no one standing to welcome them. There were no extra lights lit or flower garlands hung. "That's strange," he said, almost to himself, "Are they not home? But the others would've told us if they weren't!"

He walked up the stairs leading up to the heavy, wooden gate. The door was unlocked. As usual, he thought. He walked into the sprawling courtyard, Subhadra trailing along awkwardly. In the inner sanctum under the archway, stood a dark figure. Balrama smiled as he saw the man.

"Grand gestures are for strangers, my son can walk right in."

Balarama dashed to embrace the man, both of them tearing up slightly. Balarama turned and beckoned his sister, "Subhadra, meet him. He is our Nand-baba, and Baba, this is my Bhadra, our little sister!"

Subhadra smiled politely and went to touch his feet, utterly unaware of the fact that Nand had gone white as a sheet. Balarama, noticing immediately, quickly ushered his sister to the guestroom.

Balarama walked out to the courtyard to find Nand pouring some soma juice into two large chalices. He sat down beside the old man, "I probably should have told you I was bringing her."

"Yes, you should have." Nand turned away.

"Come on, Baba, you can't lie to me." Balarama took a sip from one of the cups, "It was a tough call you made. There was always going to be only one: either Kanha or her. I have lain awake several nights pondering what I would have done in your position. Before it was so simple- save the saviour, but ever since our Shashi came to us, I cannot make a decision! I love Kanha, but I do not think I would have been able to give up my Shashi, even if it was his life on the line!"

Nand sighed, "I do not care how brave people say I was. Do not tell me how Kamsa was the one who killed her. I sent her to him! I made that decision, to end one life for another. There is blood on my hands that will never be washed away."

"Subhadra is innocent in this. How is it fair to punish her?"

"I am not punishing her. Haven't you heard the rumours? They say she is her, reborn! How can I look in those eyes after what I've done?"

Balarama refilled Nand's chalice, "I get it, Baba, but the rumours are baseless. She is her own person. She doesn't deserve to be seen as someone she is not. Also, is it fair to replace her? She who gave herself to give us victory, in more ways than one! She gave us Kanha! Is it so easy to replace her sacrifice with another child? Subhadra deserves a chance to have you in her life in the same way as we have! Besides, where's Yashoda-maa, does she not want to see us?"

---

Yashoda had concealed herself in her chambers when the boys had brought news of their arrival.

Krishna had not come with them.

An overwhelming emptiness had suddenly engulfed her. She had watched Balarama walk in from the window in her bed-chamber. He had come up to talk to her after dinner but she had locked the door. After knocking for a few minutes, he had left thinking she was asleep. The truth was that she had stayed awake all night, pacing up and down the room. Up until then, everything had seemed surreal.

There had been a faint hope that Krishna would return, and then everything would go back to normal. Seeing Balarama walk in with their new sister, without Krishna, had suddenly made everything so very real. It felt to Yashoda like the invisible wall between her and Krishna was finally cemented.

---

As the sun rose, Yashoda straightened her mostly undisturbed bed and went out to face her bland, ordinary day. Outside, she found the young princess standing in the centre of the corridor. Her hair was tied back neatly in a tight braid, and she wore bright yellow apparel. In the darkness of the night, Yashoda had not realized how much her face resembled Balarama. However, her mannerisms reminded Yashoda of Kanha. She stood upright in a regal fashion, but her eyes were lowered in deference.

"May I know who you are?" Yashoda asked, although in her mind she already had guessed.

The girl looked up, "I am Princess Subhadra, daughter of the great Prince Vasudeva and the pious Princess Rohini of Mathura, granddaughter of the illustrious King Ugrasena of the renowned family of Yadavas, ruler of the kingdoms of Mathura and Dwarika, niece of the distinguished Lord Nanda, ruler of Gokula and Vrindavana, and sister to the unparalleled warriors- Prince Balarama, viceroy of Mathura and Prince Krishna, viceroy of Dwarika."

Subhadra's words seemed like a twisting knife lodged in Yashoda's heart. The one this girl spoke of, is Devaki's Krishna, not Yashoda's! Still, the girl is innocent, she thought and forced herself to smile once more. Clearly, the girl had been taught to parrot off her titles from a young age.

She smiled at the girl, "Well, I am Lady Yashoda, Consort to the Lord of the realms of Gokula and Vrindavana, Mistress of the household you currently grace, and maiya to anyone who's interested."

Subhadra's eyes lit up immediately. Dropping the regal demeanour, she sighed with relief, "I hate having to do that, maiya! Rama makes me practice that all the time! He says how we conduct ourselves should always reflect the standing of our illustrious family!"

Yasoda laughed, "Yes, he does find happiness in perfection. I see no reason why he shouldn't inculcate the same values in his sister!"