azonenberg | berndj: LOL | 03:08 |
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azonenberg | that woulud be hilarious | 03:08 |
azonenberg | i want to see it happen | 03:08 |
berndj | nandminer | 03:08 |
berndj | care to speculate on why the MH/J (something like 0.08MH/J _at best_) is so terrible? is it the relatively giant transistors needed to drive external pins? | 03:11 |
azonenberg | Probably | 04:50 |
azonenberg | well, also | 04:50 |
azonenberg | sec, let me find pics | 04:50 |
azonenberg | http://i.imgur.com/iJ5Lg6a.jpg | 04:52 |
azonenberg | This isn't a perfect stitch, you can see the edges should be straight but arent, it was one of my first die pics | 04:52 |
azonenberg | 7407 | 04:52 |
azonenberg | hex buffer with open collector outputs | 04:53 |
azonenberg | you can see there's a few internal buffering transistors and then the giant pad drivers | 04:53 |
azonenberg | so those obviously pull quite a bit of power | 04:53 |
azonenberg | But also, look how big the inner transistors are | 04:53 |
azonenberg | and how huge all of the internal signal wires are | 04:53 |
azonenberg | that's a lot of parastic C to drive every time you change a signal | 04:54 |
azonenberg | The pin at far right is ground | 04:54 |
azonenberg | far left is power | 04:54 |
azonenberg | then each pair of pads is input (the one not connected to the giant transistor) and output (the giant transistor) | 04:55 |
azonenberg | One of the benefits of old-school 74xx from a study perspective is that they're relatively simple, you can see every transistor clearly | 04:56 |
azonenberg | The downside is that since they're not standard cell based, or even CMOS, reading them doesn't help that much with understanding modern chips | 04:56 |
azonenberg | http://siliconpr0n.org/map/nat_semi/dm7474j__ns50su__semipol/ | 04:57 |
azonenberg | better pic, this is a national semiconductor 7474 | 04:57 |
azonenberg | dual positive edge triggered dff | 04:57 |
azonenberg | The resolution of this pic might be... excessive... but you can see everything clearly :p | 04:59 |
azonenberg | The black things are what looks like aluminum bond wires, wedge-bonded to the die | 04:59 |
azonenberg | berndj: as opposed to the more common ball bonding | 04:59 |
BleedingBytes | hi | 13:49 |
Sync_ | hio | 13:49 |
BleedingBytes | I've just stumbled into this channel | 13:51 |
BleedingBytes | and I'm a bit amazed that there's a project for making CMOS at home | 13:51 |
BleedingBytes | lol | 13:51 |
BleedingBytes | just wanted to say that | 13:51 |
BleedingBytes | I'll keep in mind to watch how this goes | 13:51 |
BleedingBytes | I want my home-chip-fab too :) | 13:52 |
BleedingBytes | chip-home-fab* | 13:52 |
nmz787 | hi BleedingBytes ! | 20:16 |
BleedingBytes | hi | 22:47 |
--- Mon May 27 2013 | 00:00 |
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