Topic for #homecmos is now Homebrew CMOS and MEMS foundry design | http://code.google.com/p/homecmos/ | Logs: http://en.qi-hardware.com/homecmos-logs/
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<bart416> azonenberg, http://www.keil.com/forum/11867/
<bart416> ^you should totally try to gravedig that thread :')
<azonenberg> lol
<bart416> Also, any suggestions for a transistor level flank triggered D latch?
<bart416> *rising edge
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<smeding> hahaha that thread
<smeding> bart416: do you need a schematic? i can rip one from a book of mine
<bart416> smeding, anything is welcome :P
<bart416> My design is not that uhm, great :p
<bart416> Uses way too much transistors in my opinion
<smeding> eh, latches use a fair bunch of them usually
<bart416> Too much heh :P
<smeding> the one here uses 22 transistors
<smeding> let me see what the actual SoG implementation for our uni project does
<bart416> well, if you're going VLSI or better it's not much of an issue if it works fast
<bart416> The thing is, I don't want to be using 160 transistors per 8 bit word
<smeding> do you want one with a reset
<smeding> and if so, sync or async?
<bart416> that doesn't matter that much actually
<smeding> i'll take a picture
<smeding> sec
<smeding> that's an implementation that's actually used
<smeding> it's for a 1.6u SoG process though, hehe
<smeding> but i don't think it should matter all that much
<bart416> Urgh, I'm using BJTs :P
<bart416> I have enough books on CMOS design to build a desk out of them by now I think
<smeding> well you should have mentioned that :p
<smeding> i don't have any books on TTL or anything
<bart416> It's RTL as well :P
<bart416> TTL is tricky in discrete components for reasons I'm so not getting into lol
<smeding> ah
<bart416> I'll leave it at you're quite often largely dependent on somewhat similar hFEs
<bart416> I can't count on that
<smeding> ah yeah
<bart416> I'm using 2N3904 bjts in my design
<bart416> so min hFE is about a hundred
<bart416> It should work as long as hFE stays above 50 or so
<azonenberg> Well you're also dependent on multi-emitter transistors if you build them the classic way
<azonenberg> I like CMOS
<smeding> me too
<azonenberg> And I want to build it :p
<bart416> BJT is cheaper and actually faster in this case
<azonenberg> Something as complex as a FF might take a while to be able to make
<bart416> It's easier to design a "high speed" BJT circuit than a MOS one
<smeding> ECL!
<azonenberg> I do wonder if Jeri's process would work with BJTs
<azonenberg> Because I have a pretty good idea of how to do a home MOS process
<azonenberg> I actually want to try prototyping a CD4000 series chip on a PCB with discrete FETs
<azonenberg> make sure i have the circuit right
<azonenberg> Using a standard-cell based design
<azonenberg> But actual fab is still a ways out
<azonenberg> I want to do a comb drive soon
<azonenberg> Just have to find the time to actually work on it ;p
<azonenberg> And make a new spin coater controller
<bart416> Best I've got right now is actually the very old trustworthy digital design, replace gates with transistor equivalents
<bart416> that'll do it with 18 transistors
<bart416> I fear I'll have to switch my design to 4 bit
<bart416> or 6 bit
<azonenberg> bart416: I would not attempt anything more complex than a single CD4000 chip
<azonenberg> until you have VLSI down well
<bart416> VLSI?
<bart416> I'm building discrete...
<azonenberg> ... oh
<bart416> That's why I'm worried about transistor count
<bart416> I don't give a damn about speed at this point actually
<bart416> I'm happy with 1kHz in fact
<azonenberg> lol
<bart416> My current method should alllow me to go past 100 kHz though!
<azonenberg> Very nice
<azonenberg> Btw, I was just thinking
<azonenberg> I can hit 12um on a film mask
<azonenberg> design rule
<bart416> yes...
<azonenberg> if i feed that into 10x reduction thats 1.2um design rules
<azonenberg> On an area about 1.6mm across
<azonenberg> Which should be enough to actually build something of useful complexity
<azonenberg> I think some time in the next week-ish i am going to try making a flip chip BGA
<azonenberg> Something of trivial complexity, not even projection litho
<bart416> If you do that you might be able to get some donations (to buy new equipment)...
<azonenberg> just contact at few-hundred-micron feature sizes
<azonenberg> IOW an inert packaging dummy
<azonenberg> but if i can conduct a signal from balls A1 to A2, B1 to B2, C1 to C2
<azonenberg> and not short between the pairs
<azonenberg> That will tell me the packaging technique is sound
<bart416> and you won't need to be nearly as careful at those feature sizes...
<azonenberg> Yeah
<azonenberg> The goal is to build a FCBGA in an amateur process
<bart416> and you could make 7400 series ICs already
<azonenberg> Even if the device is inert
<azonenberg> And i cant do 7400 yet
<azonenberg> i dont have dopants
<azonenberg> or a furnace
<bart416> oh :(
<azonenberg> I mean, my litho is good enough
<azonenberg> I just have to get the other tools
<azonenberg> its probably a few more months of work
<azonenberg> i'm right on the edge
<bart416> I guess I'll just ask a professor about it tomorrow
<bart416> btw, I pissed somebody off at an auction yesterday evening azonenberg
<bart416> I did a Google
<azonenberg> lol
<azonenberg> explain?
<bart416> Was placing bids based on physical and mathematical constants :P
<azonenberg> Lol
<azonenberg> I approve strongly
<bart416> So did the fellow engineering students that were there, sadly we weren't in charge of the auction :P
<azonenberg> lol
<bart416> So the polsoc major that was doing it got pissed cause he couldn't remember the numbers we were throwing at him
<azonenberg> lol
<bart416> ok, in his defence he might not know that the square root of pi is 1.772454
<bart416> But that's no excuse to suck that much :P
<azonenberg> lol
<azonenberg> sqrt(pi)?
<azonenberg> Why not sqrt(2)
<azonenberg> 1.414 ish
<azonenberg> or were you trying to beat 1.50
<bart416> Well, multiplied by 10 that is :P
<bart416> So 17.72 euro was our bid lol
<bart416> ofc we were shouting "TEN TIMES THE SQUARE ROOT OF PI"
<bart416> Actually, that might have been why they kicked us out halfway
<bart416> Well, two reasons
<bart416> 1) We were buying everything
<bart416> 2) We were being assholes
<bart416> 3) Constant math jokes
<bart416> Number 3 not being a real reason to get kicked out
<bart416> (Number 1 is problematic cause it's for some good goal and they were auctioning dinner seats :P )
<bart416> But we bought the entire table of 20 people with 7 xD
<bart416> well yeah, 20 pairs of people I meant sorry
<bart416> Considering most of us don't even have a relationship we'll take up 40 places with 7 people
<bart416> And that all for the price of 173.8 euro in total...
<bart416> Considering the restaurant it's a bargain lol
<azonenberg> lol
<bart416> The polsoc idiot also managed to sell his own bike without realising it :')
<azonenberg> lol
<bart416> One of his "friends" put it in between the items
<azonenberg> lol
<bart416> And it was described on the list as "bicycle, used"
<azonenberg> Dummkopf :p
<azonenberg> What'd you buy it for
<bart416> And he was too lazy to bring it up to the stage so he never noticed it
<bart416> Nah, we didn't buy it
<bart416> We didn't know it was his bicycle until the "friend" in question told us
<bart416> I'll just leave it at, it went cheap
<bart416> There were some nice items though
<bart416> Several rare books
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