just thinking about these DIP-8 packages that have been converted to surface mount by trimming the leads short and bending them outwards. this is an official IC package! it's called DIP-8 gull wing.
but why not just make them in a standard SOIC package? turns out there's a very good reason.
you need the internal spacing between the LED and photodiode to meet the voltage isolation rating. look at this pic: you're not fitting that into an SOIC.
well, you *can* but it'll end up looking like this silly thing
DIP-8 gull wing is also used for clock oscillators because you need room for a quartz crystal and an oscillator chip. it's possible but difficult to cram that into an SOIC, like this DS3231S.
you can also get DIP switches in the gull wing style.
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oh look it's a working IBM 5154 enhanced color display, and it's on the auction site.
these monitors can handle 15.7KHz for the 200 line modes as well as 21.8KHz for 350 line modes. the polarity of the vertical sync signal tells the monitor which of the two modes to be in. that's about it.
there are better monitors out there, for sure. i like the original NEC Multisync because it can handle lots of different frequencies and standards, analog and digital.
i've been thinking about the Surfside condo collapse. 🧵
i'm a bit hesitant to write about it, mostly because i keep thinking about the folks trapped in the rubble. it makes an engineering discussion seem a bit cold-hearted.
but engineering affects all of our lives -- which, on a daily basis, literally depend on engineers doing a good job. most people take this for granted. it's probably why a catastrophic failure like this can affect us so deeply.
a while ago i picked up this old DAT drive for a very good price. let's see if i can get it working!
it is the Mitsumi DK4-SS4001, a SCSI DAT drive.
took out a bunch of screws and now we're in! DAT drives use a helical scanning system just like an old VCR, but in miniature. the round thing in the middle is the rotating head.