VTC P.34 – Building the Paper Tape Interface

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Название	:	VTC P.34 – Building the Paper Tape Interface
Продолжительность	:	25.10
Дата публикации	:
Просмотров	:	32 rb

Hey everybody, thank you so much for all the awesome comments!brI’m seeing a lot of similar questions, so I figured I’d answer them all in one go here:brbrWhy not use the tractor feed punch for a clock?brPrimarily, the entire paper tape portion of the build is a massive question mark right now At the bare minimum I know I have to have 8-bits coming in and that’s it So, I wanted to design the system to work with the absolute bare minimum in case we run into troubles designing the paper tape interface from scratchbrbrWhat about losing your NOP0 instruction?brThe processor actually has two NOP instructions, one at 0000 and another at 1111, both have external flags they set (Flag 0 and Flag F) and both are currently unused Losing the NOP0 instruction doesn’t actually hinder the processor in this casebrbrPaper tape isn't random access, so you can’t do branching instructions!brActually, you totally can The MC14500 (and thereby UE14500) was designed to work with any sort of crazy program control you could think of, so instead of branching instructions being done by jumping the program counter, they are instead done by masking input and output Every instruction is actually executed, just the instructions we want to skip don’t produce any results or have any effect on anything The Minimal ICU System on the PCB that I show at the beginning does use a ROM, but the PC isn’t jumpable at all, yet we still managed some tricky stuff with it (like playing Kill the Bit)brbrYour design won’t work at higher speeds!brNo worries, the rest of the processor is so poorly designed that it won’t work at higher speeds either, haha Seriously, I’m aiming for 455 Hz clock speed That’s just 4-inches per second, which is glacial for both paper tape and the computer Because of this, we have a lot of leeway
Comment from : @UsagiElectric

Why oh why would you turn the cameras off for the cat petting time? Come on!
Comment from : @Griwes

Isn’t there a c,lock/sync track in the middle of the paper tape?
Comment from : @berndeckenfels

Do you use lead based soldering wire or silver based ?
Comment from : @VandalIO

Bloody logisim
Comment from : @VandalIO

Run a continuous loop of tape that has like 512 bytes on it Just need a motor driver you can stop on a "halt" and restart the same way you would the pc Clock comes from the sprockets It will be more capable than the single board PC that was limited to 8 bits (256 instructions)
Comment from : @maskddingo1779

I built an optical reader using 555 timers about a decade ago It was a fun project
Comment from : @maskddingo1779

Imagine rebuilding Pentium 1 processor using vacuum tubes
Comment from : @hotasianstepsister3039

What does your wife think of all this?
Comment from : @tjaeoij32

Going with an optical reader or a mechanical one? Some of the old punch-tape readers for things like marquee signs were optical, as there were no contact brushes and such to wear out and the punch paper itself would last much longer with nothing dragging over it Photoresistors pre-date vacuum tubes, so it would be "period correct" as some element of a retro-designed system Just thought that may be worth a mention
Comment from : @pauljs75

Dont think you should lose your NOP instruction You may need this operation to allow for prop delay on your system
Comment from : @Dont_Gnaw_on_the_Kitty

Notification Squad! :)
Comment from : @tjtarget2690

I am super looking forward to the paper tape reader component! I love that sort of mechanical-electrical interface design
Comment from : @PhysicsGamer

Came for the computer, stayed for the bunny
Comment from : @brettsalter3300

When you said "get out the 'scope" I envisioned a modern DSO but hoped for something analogue with tubesbrThank you for that pleasurable surprise !
Comment from : @MrLampbus

Cats always take precedencegood to see you have interrupts implemented well (Katurrupt ?)
Comment from : @MrLampbus

6:51 This man has his priorities set correctly
Comment from : @dhammar73

So it will be able to branch forward but not backward I am imagining how I would code in such an evironment but my brain exploded I anxiously awake further developments Well done!
Comment from : @rickhole

I really enjoy your project, vacuum tubes Rule! Thank you
Comment from : @olddisneylandtickets

1:03 Yeah, but no That's not very micro🤔
Comment from : @patrickradcliffe3837

The sudden feline interruption perfectly displays how life is with a cat 😂! brbrThe rest of the video was the good stuff I am used from you, always a pleasure to see you tinkering!
Comment from : @benedienst

"I'm going to have to turn the cameras off and play with the cat for a little bit" I agree with the second half of that statement but strongly disagree with the first half
Comment from : @eDoc2020

I wish I could give two thumbs up, one for epic project and one fot cat
Comment from : @nysaea

When I put together my MC14500 based design I had timing issues when the 8-bits from the stored instruction and data in an EEPROM arrived at the 14500 and when the timer clock 'clocked' the instruction in Solved the issue using the delayed clock approach in your paper tape interface, with the master clock feeding a few schmitt triggers and an RC circuit to clock the 14500 Introduced a sizeable delay, but at a clock speed range of 1hz to 2khz it works fine Enjoying this series - always something to learn Cheers N
Comment from : @nigelcleaver

I'm asking a few YouTuber's this questionbrbrI need to replace the filter capacitors in my reel to reel tape deck,brone is 1250uf 40V and the other is 2500uf 64V (this capacitor is on a 45V rail)brI can't find either of these capacitors, I'm wondering what would be the best replacementsbrbrI have found 1200uf 63V and 2200uf 63V capacitors,brcan I use these for long term use instead ?
Comment from : @frankowalker4662

Hello, can you tell me what machine is shown in the intro that mills PCBs?
Comment from : @stefanobianchini8217

How is your electric bill these days?
Comment from : @mikehughesdesigns

If you ever need that NOP0, remember that the normal (7,4) Hamming code fits 4 bits into 7, leaving an extra bit for synchronization while also providing some resiliency to errors
Comment from : @absalomdraconis

If that were my cat, he'd steal your seat while it was still warm The cat at the door would be a diversion
Comment from : @neilbarnett3046

This is so cool Now it just needs some core memory…
Comment from : @iainportalupi

Love your projects, if it is the Bendix or the Centurion or the VTC or everything in between Thank you for this very entertaining, interesting and educating content
Comment from : @Hutschnur

I'm looking forward to you loading the game "Kill the Bit" off paper tape
Comment from : @danaeckel5523

Very clever, I love it!!
Comment from : @rlbf1967

> It's getting bigger and biggerbr> It's getting tighter and tighterbrbr"That's what she said"
Comment from : @klocugh12

The cat is very cute, the video should have been you, playing with the kitty; adorable ❤😊 Cute rabbit eating at the end; you like your animals
Comment from : @neilthomas6042

"Don't let your electronics sit too long"
Comment from : @martinmartin1959

It’s so fuckin Cool to see how the same sorta tubes I use to get my guitar sounds can be used in other applications I’m used to just goosing these motherfuckers SO HARD & clipping the FUCK outta any signal going through, so seeing it in SUCH a different context is neat as hell!!
Comment from : @EclipseAtDusk

You need to start a new channel, 猫電気
Comment from : @hamishwatt2475

Paper tape has a feed hole You can use the feed hole as the clock and eliminate the NOR gate as well as the delay
Comment from : @zubble7144

I don't mind kitty breaks, btw
Comment from : @RockyBergen

"cat tax paid", I like it
Comment from : @stinchjack

You sir are an absolute nutter, in the best way - converting silicon circuits into tube circuits - I've not seen the rest of this series (obviously seen many of your videos) so I don't (yet) know why you're dong this but from what I would surmise - because you can! I shall certainly delve into the earlier videos 👍
Comment from : @ancipital

1
Comment from : @mz4637

we need more cat tax!brmore kitty!
Comment from : @lachee3055

We demand 20 minute video of Usagi Electric playing with cats !
Comment from : @soniclab-cnc

Cool Can we have a transistorized version?brEdit: oh wait its the single board one
Comment from : @josha254

For Usagi's NEXTY trick, adding a finch drive interface to system :)
Comment from : @mysticvirgo9318

Cats rule!
Comment from : @glenncaughey5044

I think showing 30 minutes of playing with the cat would be almost as interesting as the rest of the video Might get you some higher click rates as well 😃
Comment from : @RichardSmithers

I don’t think this would be possible without the cat… my theory is that petting and playing with cats unlocks our minds…
Comment from : @starbuck1776

You were lucky the others were not lined up at the door waiting their turn 🐈🐈‍⬛🐕🐇🐈
Comment from : @wmrg1057

I think you should check out the design of the vintage Oliver Audio Engineering Paper Tape Reader from the 1970s era It is pretty much a minimal paper tape reader
Comment from : @josephwatson4616

Sounds like fun Back to the future?
Comment from : @oldfarthacks

🐈💰
Comment from : @seekingthelovethatgodmeans7648

Came for the Paper Tape Interface, stayed for the cat
Comment from : @esra_erimez

6:52 you are truly a wonderful human being
Comment from : @esra_erimez

Pulse digital switching waveforms by Millman Taub brpage 441, says adding diodes in series with coupling capacitors of the 12au7 multivibrator squares up the output waveform
Comment from : @mohinderkaur6671

Definitely cannot avoid the cat tax
Comment from : @JamesTK

Awwh! The kitty break was sweet! ❤brbrIt amazes me how this is simultaneously so simple yet so complex I keep struggling to wrap my head around it but if you isolate any single piece it seems so simple
Comment from : @oliverer3

BONUS CAT FOOTAGE!
Comment from : @stamasd8500

The vacuum tube computer will certainly be a cool thing in it's own right What are your future use plans for the machine?
Comment from : @tim_bbq1008

I won't lie, about 60 of what you say and do in your videos is totally beyond my skillset It's your passion, enthusiasm, and eternal tinkering that keep me coming back for every single video The fact that you even mill your own boards just adds to that Love your content, dude!
Comment from : @tocard3

The UE1 is a fantastic project and I am looking forward to seeing it in function! Keep going!
Comment from : @MarcelHuguenin

Do you suppose it would be possible to interface a paper tape reader/punch to the Centurion ?
Comment from : @user-eg3yv3xr7s

Love this channel! Thanks a lot!
Comment from : @moorlo999

interesting episodebrbut I think you could have skipped a few steps by using the schmitt trigger i designed for you
Comment from : @robot797

Please post videos of your kitty
Comment from : @BestSpatula

Be careful your cat isn’t trying to turn you into a Blofeld 😉 The thought crossed my mind about using the sprocket hole of the tape for a clock (which I see is mentioned already) might’ve got you your NOP back Not that you can do much with a NOP beyond code delays As always, loving how this is coming together 😊
Comment from : @timothyp8947

Your design looks great on paper but as soon as you load well actual paper, you will notice "phantom signals" when one hole already reached the beam but adjacent one didn't And while tubes are a lot slower than FETs, the speed is counted in nanoseconds - many orders of magnitude faster than the tape brbrThings get even trickier when the punch reader reaches its design speeds of a few meters of tape per second aka "finger-dismemberment speed" (beware surprise catastrophic paper tears and jams BTW)brbrbr"the delay circuit" can provide debouncing needed but you should carefully tune the delay It should ideally be set to a maximum transition interval (time needed to pull the tape from one set of holes to the next and stop there) plus a bit more - see your punch reader docs if you have any or experimentbrbrBut more importantly the punch reader hardware itself should require tape pull (clocking) signal and probably provide a "ready to read" signal (though yours may work differently) That last one should be used as read clocking input Please make sense of it bbefore/b constructing any supporting circuitry Although adjustable delay will most likely still be requiredbrbrAs others suggested below some punchtape systems have special smaller holes just for synchronization aka clockingbrbrbrYes you can still do it your way but I don't really see the need for a dozen of extra tubes and supporting circuitry
Comment from : @jwhite5008

While Sue was begging you to pet her, my cat Stars was begging me to feed her By digging her claws into my leg Despite the fact that her dinnertime isn't for two hours yet
Comment from : @danmenes3143

You truly are an artist: The layout of your PCBs is beautiful, as is the overall placement of the components and boards Great stuff!
Comment from : @markmuir7338

Master* Ken Shirriff
Comment from : @Kaislab

I enjoy watching your channel Your work has inspired me too attempt a relay-based processing unit 😸
Comment from : @e7yu

Our cat overlords must be appeased This is priority
Comment from : @briannaschuman547

Hello Thanks for your videos, I really like your channel brWith a paper tape, you cannot do RANDOM access Branch instructions are therefore impossible This is a huge limitation, and the result is not really a "computer", without branch instruction brIt was not possible to build or use a CORE-ROPE memory for the ROM, for storing the program?
Comment from : @F4HDK

I really like when you use the vacuum tube scope 😁
Comment from : @glufke

Never apologise for taking time out for some kitty love, however important the thing is that you're working on
Comment from : @johnm2012

In the 70s I worked with paper tape, and the optical readers I used used the smaller sprocket hole for the clock
Comment from : @nezbrun872

If you can bring yourself to say "fourteen five hundred" every time, you could save about a minute in video length Times 30k views, that's 500 viewer-hours, or 60 viewer-days, or 3 viewer-months
Comment from : @ClausB252

Neko break!
Comment from : @rsbohn

I was like #256 :) It still amazes me that there are people building new computer systems using vacuum tubes Definitely good progress going on Yes, our cats run the household When they want something we humans have to drop what we are doing and see to their wants/needs
Comment from : @kevincozens6837

Can it run crysis
Comment from : @enderlore1337

I absolutely love your curvy tracks, very vintagebrAlso, can't wait to see what you do for the paper tape section
Comment from : @simona625

kool
Comment from : @68hoffman

I'm curious why you didn't use 9 bits for the tape You could have used the 9'th bit as the clock and also adjusted it's delay and phase based of the hole size and location
Comment from : @brianhginc2140