ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
<cr1901_modern>
well that rules me out lol
<Wohali>
hm, i have an MS
<cr1901_modern>
I DNF'd
<ej5>
cr1901_modern, it's for making the current mirror more symmetrical by reducing the base current draw from the reference side of the mirror
<cr1901_modern>
I see... cool!
<cr1901_modern>
so it's to compensate for unmatched transistors
<cr1901_modern>
like a "super" current mirror or something
<ej5>
it's called a buffered feedback current mirror
<cr1901_modern>
I have a 2010 edition of Sedra and Sm- oh, this is a free textbook
<fseidel>
ej5: might give that a shot. I always wanted to take analog courses in both undergrad/ms but never had the space in my schedule
<fseidel>
thanks for the rec!
<cr1901_modern>
I got an A-minus in electronics. I did not deserve that A-minus then; I _did_ get better at analog by the time I graduated, but I have trouble remembering stuff like how to calculate hfe and the sat/linear equations for a mosfet
<cr1901_modern>
hfe has some temperature correction in the divisor if memory serves
<ej5>
it's kinda approximate anyway
<ej5>
BJTs are really voltage dependent current sources, but the base has this nasty parasitic diode that allows current to flow to the emitter
<cr1901_modern>
I've always modeled it as current controlled current source
<cr1901_modern>
In part b/c that's what "Beta testers" on multimeters measure
<TD-Linux>
sedra and smith is very lacking in practical designs
<cr1901_modern>
I thought it was a good textbook- it's one of them I actually still consult :P
<cr1901_modern>
Sedra and Smith is good for the math, Horowitz and Hill is good for "you need to get shit done"
<TD-Linux>
yeah I guess normally what I want is "pls spoonfeed me a topology"
<cr1901_modern>
I could make a tweet on hellsite for more collaborators- or not
<Foone_>
I'd help advertise it
<cr1901_modern>
The offer to get boards made might be limited to ppl in here :P. So I want to be sure first.
<Wohali>
i'm fine with whomever, i don't care about google docs or not, set up a google form/survey thing so ppl can put in their mailing info & # of boards
<Wohali>
1. get enough names 2. people pay
<Wohali>
3. i order them
<Wohali>
4. i ship them
<Wohali>
busy rn but can talk more later
* cr1901_modern
nods
<Wohali>
ej5: where's the repo so I can check that i can load/read the design?
<Wohali>
Lord_Nightmare: i'm not doing oshpark, it'll be cheaper. I use blue for all my personal stuff
<Lord_Nightmare>
ISA is also a pretty reliable connector and a decent* standard
* cr1901_modern
concurs
<Lord_Nightmare>
* if you ignore ibm's bullshit with edge triggered irq lines at least and do proper level triggering, that is. that's the biggest flaw in ISA
<cr1901_modern>
Wohali: What's special about green, is it cheaper?
<Wohali>
ISA is fine, though for lower pin count I prefer MTA156, esp. if ther'es going to be any analogue content
<fseidel>
cr1901_modern: I don't have a machine to put it in, but CMU's computer club may be interested, I'll bring it up this weekend
<Lord_Nightmare>
eurocard connectors are way better than ISA reliability wise
<fseidel>
"monitor smoke, don't breath this" - the 'Will It Blend' guy
<fseidel>
*breathe
<cr1901_modern>
vita mix lost a lawsuit to that guy
<fseidel>
oh really?
<cr1901_modern>
according to wiki anyway
<cr1901_modern>
and my family loves vita mix because it can be used to cook soup LOL
<fseidel>
yeah, my uncle used to brag about making soup with his vitamix
<fseidel>
what an odd feature
<Wohali>
i am so tired :(
<cr1901_modern>
I know that feeling
<Wohali>
cr1901_modern: this is fine for pass 1, for pass 2 obviously I'll need shipping addresses/etc, which I can run thru PayPal I guess. Let that handle the GDPR side of things, since it's part of doing a business transaction with ppl
<Wohali>
maybe add a field for destination country
<Wohali>
so I know roughly where things are going
<cr1901_modern>
Wohali: My original draft _had_ shipping address. Want me to put that back in?
<Wohali>
Added
<Wohali>
i think htis is fine
<cr1901_modern>
Idk how the paypal side of things is gonna work... I have two accts (one personal, one business). Does Paypal allow you to collect payments that are reserved for a specific product (as well as shipping info, etc)?
<Lord_Nightmare>
i can't answer that, you need to consult paypal docs
<Wohali>
yes, it does, i can deal with it
<cr1901_modern>
awesome
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<whitequark>
hm
<whitequark>
so, OPLL has an integrated DA converter, *but*
<whitequark>
it says that it outputs OPLL test data to D0/D1 pins with certain bus state
<cr1901_modern>
I posted about it on VCF because I was excited, and a number of posts were accusing ej5 of making it easy to pass off clones as originals
<whitequark>
you literally just look at the pcb substrate
<whitequark>
old substrate was fucking junk
<ej5>
yeah people were super pissed :P
<whitequark>
you cant find a board house bad enough to actually reproduce an adlib quality pcb
<whitequark>
they dont exist anymore
<cr1901_modern>
I mean, adlib isn't a difficult card to make on your own (this is not a slight against your work ej5)
<ej5>
of course, i also cloned the ultra rare IBM extender/receiver card pair
<cr1901_modern>
either*
<gruetzkopf>
ej5: ooh
<gruetzkopf>
for the 5161?
<ej5>
posted that on VCF, nobody gave a shit
<whitequark>
lol
<ej5>
yeah for the 5161
<TD-Linux>
obviously all original adlib cards need to be graded and encased in VGA hermetic cases
<cr1901_modern>
VGA?
<cr1901_modern>
Not the video standard I'm guessing
<gruetzkopf>
hmm i could maybe use that
<TD-Linux>
cr1901_modern, google it
<gruetzkopf>
i have a XT clone board and another case with a more modern industrial 14-slot isa backplane
<cr1901_modern>
ej5: Anyways, even if VCF is pissed and are a ultra grumpy gatekeepers, _I'm_ proud of the work you've done :3! You've done a great public service!
<cr1901_modern>
a bunch of*
<ej5>
thanks man :)
<ej5>
gruetzkopf, the IBM cards work fine in passive ISA backplanes, with one caveat: the 14.318KHz oscillator is not provided
<gruetzkopf>
yeah but that's no trouble
<cr1901_modern>
MHz?
<ej5>
*coughs* MHz
<gruetzkopf>
i have a good handful of those in DIP14