#1594

[@pglick123]

..."use your imagination" videos made for radio 🤣. Thanks, I love them!

[@BJcanal270]

Simple explanation but very informative!! Thanks for sharing

[@____________________________.x]

4:42 reminds me of my Control Theory lecturer who stood in front of a scrolling blackboard writing furiously, leaving us to frantically copy down the tiny section still visible above his head before it disappeared. All while trying to understand what he was on about 😑 Thank goodness for being able to learn stuff from KZbin channels now

[@jrkorman]

As has been mentioned; protecting an internal data bus or part, bringing address or status onto an external bus for example. I have an old PMC Micromate 101 Z-80 based computer and the first thing they do is isolate the CPU address lines from EVERYTHING with a set of '244s. All of the CPU status lines (RD/WR, etc) are also isolated with '244s. The bidirectional lines (data) are '245s. Good, solid early 1980s engineering. TI datasheets use 3-state because Tri-State is a trademark of National Semiconductors.

[@____________________________.x]

I kinda miss those days. New Z80 boards don’t have anything buffered now. Feels wrong

[@0toleranz]

Serious bus based systems were designed to be expandable beyond just a couple of chips on the CPU‘s bus they could drive loads of cards and even expansion chassis and with tel loads you had to drive the bus to be able to have even 64k of memory with 4116s and some I/o controllers. With modern CMOS SRAMs in sizes the z80 wasn’t even ment to use and the whole support chips family all in cmos too you can build systems like an rc2014 without thinking twice about power consumption, load capacitance and drive strength while having an z80 at 7 or even 18 MHz running cp/m at speeds never imagined by its developer in the 70s and 80s. On the other hand small systems like all the 80s home computers never needed busdrivers either because the were designed compact enough in terms of chipcount on the bus so that a couple of multiplexers for the RAM were enough to facilitate the row column addressing as well as bringing the TTL load down from 8 to only 2 which often was enough to have every thing else (ROMs, graphic, sound, floppy, parallel ports… like in the Amstrad CPCs or MSXs) on the bus.

[@iblesbosuok]

Internal schematic diagram explained in 74LS125A datasheet. You can use 74LS541 to simplify board layout. Unfortunately 74LS541 has different enable scheme.

[@fritzkinderhoffen2369]

I'm really appreciating your going over these chips. Some of these things I was familiar with back in the late 70s / early 80s but now find relevant to a project I've set myself to. So thanks for a yet another fine video.

[@davidsmith9063]

The 74ATB541, one of this chips weird cousins, happens to be my favorite line buffer for I2S digital audio projects. See "favorite" as "I bought too many, but they are good parts", like you and .01 and 10K I believe..😁

[@broklee]

Great clear and concise video. Very informative. Not aware of anyone else doing these types of videos

[@jimmydburrell]

Once upon a time you did a vid (chip o-the-day) about a PLD / PLA / PLC ? Consider this my official request for another of those complete with a little program as before. Thank you!!

[@mikebond6328]

Baaaaa! It’s transparent…. unlike fingers. Aaahaaaaa. 😂

[@intheshell35ify]

OMG those 4 pin power/ground terminals/loops initiated a paradigm shift in my breadboard work. So many possibilities. I'm kicking myself for not discovering it on my own.

[@IMSAIGuy]

www.pcbway.com/project/shareproject/Protoboard_Power_Connector_55084a5d.html

[@Batmule]

"Use your imagination" 😀

[@zexusdexus4193]

Exactly what I was trying to figure out last night: how to drive an LED from a flip-flop. And got hung up on negative current. A question: as the Ioh is -15 mA, and Iol is 24 mA, how much mA of LED can this drive (LED on when in a 1 state, just like in the video)?

[@Madness832]

Oh Tri-State...New York, Pennsylvania and New Jersey?🤔😁

[@jimomertz]

I always prefer being in the high state. 😵‍💫

[@jagmarc]

244s not useful for anything much except for custom test equipment to protect unit under test, or for making your own CPU

[@danharold3087]

I used 74LS245 which is bidirectional Maybe you mentioned that. Did not watch entire video.

[@czy1854]

yo

[@R50_J0]

Not everyone loves Chip of the Day.

[@niklas2052]

in Britain they prefer Crisp of the Day