Tweets
Replying to @cabe_bedlam
it’s true! The piezo buzzer is fused to the backplate, and two contacts at the top and bottom connect the buzzer and the backplate to a signal and the positive terminal of the battery, respectively. (yes technically the back of the watch and all of the button pushers are at +3V)
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Replying to @josecastillo
I don’t yet have any way to make use of it, but I’ve long wanted to put one of these I²C EEPROM chips in the ’extra stuff’ area I’ve set aside in the watch. In theory it would let you get data in and out without having to take it apart and plug into USB. https://www.adafruit.com/product/4701
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finally putting together a JLCPCB order with all the stuff I finished over the weekend. Also thrown in: today I recalled some prior art in Casio watch mods. The NODE Data Runner included this design for an NFC antenna in the shape of the F-91W front bezel. https://n-o-d-e.net/datarunner.html
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Replying to @tarahaelle, @westcoastsal, @DrJenGunter, @SaadOmer3 and @nataliexdean
I think half the replies are conflating policy & politics. Science has always informed policymaking, but we just lived through 4 years where basically all public policy was dictated by politics. That’s not how things usually work. but I sense some folks are still in that mindset.
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Replying to @arturo182
forbidden chocolate fountain
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Replying to @JohnKennedyMSFT
You nailed it! Eurostile Bold Extended
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Replying to @josecastillo
this was fun! And it’s the first time I’ve designed PCB art in Illustrator. There’s exactly one bit on here that bothers me, but I think it’s fine, fine enough to throw it in with my next PCB order. now I just need to turn it into gerbers.
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spent exactly one hour this morning designing a PCB bezel for the blinkenlights module I laid out yesterday. Retrocomputing has put me into a retrofuturism kind of mindset; you can tell I raided 2001: A Space Odyssey for the typography inspo. Design time-lapse in next tweet.
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Replying to @sneenyc
Yesss! Doing the things, things getting done!!
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Replying to @RandyMongenel and @ZxSpectROM
Thanks, yeah, I know I shouldn’t, but I read that the Z80 can safely source / sink ~1.6 mA per pin. My thinking is that if I select current limiting resistors that limit me to about 1 mA it might be okay. plus it’s a one-off for my own learning; don’t want to over-engineer it.
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Replying to @josecastillo
in the end I also finished the weird new thing I started this morning. well, mostly finished. there’s some typography to consider. and maybe some 3D printing. IDK, sometimes you get an idea in your head and there’s no getting it out until it’s out.
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Replying to @josecastillo
Tho actually hmm maybe not. That keepout area is where the pins go when the card is inserted. So I may have to choose one or the other in the end. Oh well. that’s future-joey’s problem. at least it’s all routed.
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Replying to @josecastillo
…and now I get to bike home and enjoy the sunset.
Today was a good day.(original)
Replying to @josecastillo
three hours of doing, and my tasks are done! at @kfury’s suggestion, put down footprints for BOTH the microSD slots (I CAN HAVE IT ALL!). Technically the smaller one violates a keepout area on the bigger one, but those two pads are ground and an unused card detect; should be ok…
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Replying to @kfury
Y’know, I just might do that! The push/pull one overlaps with some mounting posts in the push/pull one, but if I let the card stick out more for that one it might actually work. Thanks for the suggestion!
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Replying to @kfury
Farnell seems to have some; never ordered from them, but I think I’m just going to design in the part that I want, and trust my future self to figure it out. like if I use the part I have on hand and I don’t like it, I’m worried I’m not going to make time to fix it a second time.
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Replying to @kfury
it’s definitely a pull-with-fingernail affair, which I wanted to avoid since it becomes kind of impossible once the gadget is inside an enclosure. the one recommended to me checks all the boxes: push-push, and easier to work with. well, all except the fact that I can’t get any :/
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Replying to @josecastillo
well dang. I had a card slot in mind. I even have it here (left). it’s not as nice as the one I use now. but it is easier to solder. then someone recommended this part and it looks ideal! But sold out, and no estimate on availability. decisions decisions… https://www.digikey.com/en/products/detail/MEM2075-00-140-01-A/2073-MEM2075-00-140-01-ACT-ND/9859685?itemSeq=364917408
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Replying to @josecastillo
well that was relatively painless. (the change is at the top right). will need to obsess over it for a couple days before sending it off to be fabricated, but it passes DRC. next up might be last up: microSD card footprints.
two hours of doing may end weeks of procrastination.
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Replying to @cabe_bedlam
I’m not sure I am familiar with it! Was I yak shaving this morning when I was working on other stuff? or now that I’m setting pins up and knocking them down
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Replying to @josecastillo
not that much later I guess. Pi Pico book. replacing all the parts on the left with the one module on the right. in theory this will make assembly much easier for folks. In practice I won’t know if it works unless I just, y’know, try it. still some re-placement and routing to do.
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Replying to @josecastillo
next up: footprint for the castellated e-paper driver module I designed. want to have a few made, but I need this footprint to actually integrate it into a design like the open book. (that’s also part of get-your-shit-together saturday, but later)
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Replying to @josecastillo
OK. I’ve got to just do this. it’s get-your-shit-together saturday, and I am going to do the work so the work gets done. up first: the watch. fixing a footprint error (improperly sized thermal pad) and rerouting two signals for additional low power functionality.
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i set out today with the ambition of finishing existing projects. it is now 3pm and my only accomplishment so far is starting a new project. why why WHY do I do this to myself.
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tech people can see a few lines of code and immediately sense its potential to disrupt industries and reshape the world. but suggest that firing misogynists could lead to a less misogynistic culture, and suddenly all that capacity for imagination is replaced with Concerns.
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Replying to @kfury
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Replying to @josecastillo
but yea as a high school student hacking in Z80 assembly on my TI-83, I vaguely recall there was an IN and an OUT instruction, as well as LD which loaded stuff from memory. under the hood this is what they did: one line or the other got set to use the bus in one of these two ways
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Replying to @josecastillo
in this case there’s only one gadget, the serial I/O peripheral, but there’s plenty of need to access memory, so you can see the pink MReq line flickering off and on a lot, whereas IOReq isn’t doing much. it’s still happening way too fast to see, even clocked at a paltry 0.3 MHz.
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Replying to @josecastillo
There’s a signal called MReq. When that’s low, the address lines are pointing to a location in memory. There’s also one called IOReq. When that’s low, the lower half of the address lines are meant to select some gadget on the other side of the bus. Indigo and pink, in the video.
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Replying to @josecastillo
So I had kind of vaguely assumed that you poked at various memory addresses to get bits from RAM and ROM, and some of those memory addresses also mapped to peripherals. Turns out that’s not how this CPU works. The address and data bus sort of does two different things.
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Replying to @josecastillo
More #RC2014 blinkenlights fun! Now with half-assed annotations, and two more lights to illustrate a concept I didn’t completely grok when I started this thread. But first, what’s happening here: I’m booting into a BASIC interpreter, and running a program that prints a sine wave.
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This exchange is illuminating for the failure of imagination at work here. In a more properly run world, we’d have less of the staggering misogyny that got this employee fired from Apple to begin with — and that would be a better world for both women and everyone else to work in. https://twitter.com/paulg/status/1392883872929615873
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Replying to @insolace
in hindsight it’s wild that this passed as a kids show in my childhood.
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Per updated CDC guidelines, fully vaccinated individuals may now whiz on the electric fence. https://twitter.com/josecastillo/status/1380567000523681793
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Replying to @ChengduLittleA
It’s working!! First try, too. Testament to good documentation by @ZxSpectROM and the community he’s created 🙂
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Replying to @josecastillo
i maked a blinkenlights. As mentioned above, the Z80 has 16 address and 8 data lines. I put an LED on each and slowed down the clock + camera. You can kinda see which bits of memory it’s accessing, and you hilariously cannot see the byte it’s reading or writing on the data bus :)
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Replying to @josecastillo
You fucked up a perfectly good protoboard is what you did. Look at it. It’s got anxiety.
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long boi
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Replying to @ElectronVillage
as the world creates a need for more and more obscure USB cables, we’ll just end up there all the time 😂
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Replying to @Hamitron
oh I thought we were talking about doge! had no idea he actually tanked bitcoin for some lulz, that’s amazing.
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Replying to @Hamitron
it wasn’t meant to be good, it was meant to be fun, and now it’s neither
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there are only so many hours in a day, and i am using all of them.
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Replying to @cabe_bedlam
Whoa, that is awesome!
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My neighborhood electronics shop has a live-stream exchange with its sister store in Los Angeles, and I can’t explain why but I find it utterly charming.
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Replying to @josecastillo
@glowascii, you are such a great interviewer! Thank you so much for your thoughtful questions and infectious enthusiasm; honored to have had the chance to sit down with you and share ideas!
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ICYMI: yesterday I had a chance to chat with the wonderful @glowascii on Hackster Café, and it was a blast! Here’s a taste; at the link, nearly an hour on open source hardware, tradeoffs in engineering, learning from smart folks / silly mistakes, and more! https://www.youtube.com/watch?v=jUJJAMM30IY
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Replying to @mattk
I think this is going to be an interesting addendum to the experiment; I sense that a lot of these fundamental concepts still apply to modern architectures, but I wonder which pieces are mostly the same but faster/bigger/wider, and which pieces are like truly radically different.
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yes, but neither of us would make the first move. https://twitter.com/bdAllison/status/1392190737677123584
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Replying to @ElectronVillage
I should have turned Percy’s lights on!!
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Replying to @josecastillo
Technically I realized after I filmed this that the screen at the end was just the boot screen for the terminal software — but after hitting reset on the #RC2014, I got the CP/M startup prompt. Which means, it works! More to add to this thread soon, but today was a good day :)
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