Search found 128 matches

by lucar
05 Dec 2018, 18:28
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Hi Guys, I have some questions about capacitors, and it's entirely possible that no one here knows the answer but I figured it can't hurt to ask. The keyboard has two of these square capacitor thingies (at least that's what I understand them to be): #1 https://i.imgur.com/FAxTeHO.jpg I believe that...
by lucar
01 Dec 2018, 22:47
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

From tomorrow I'll probably too busy to try to help You for the next 15 days.. :) Well thank you for all that you've helped me with so far. Your research has been invaluable. I'll keep chugging along in the meantime and will finish up your televideo keyboard as well! (almost done) Thank You! Keep u...
by lucar
01 Dec 2018, 21:36
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Wow Luca, I thought you said you're not an expert :lol: You must have a degree in electrical engineering! You certainly gave me a lot of things to check into. Thank you so much! I'm a software developer, I worked years in the factory automation field and debugging of machines was routine. You start...
by lucar
01 Dec 2018, 21:13
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Hi Luca, Is that the schematics for the 5110 keyboard? I did everything I could but the schematics I had are unreadable. It was not just water that made the pages stick together but some type of chemical that completely messed up the text/diagrams. This is very unfortunate :( No, it's from the 5100...
by lucar
01 Dec 2018, 11:35
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

I also noticed that Your "Keyboard Strobe" signal is pulsing. My opinion is that it should not. The normal status (no keypress pending) should be at +5V, while on keypress should go to GND , as , in this case , a Flip Latch is trigghered by a LOW signal generating the INT3 interrupt to awake the cpu...
by lucar
01 Dec 2018, 10:29
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Hi, 23.5 Khz should be fine. I think You're looking at the solid green line on the picture below. https://i.imgur.com/jg24wPW.jpg One of the problems might be that the clock pulse is not passing the AND circuit indicated in purple. In order for the clock signal to pass , the "Matrix Drive" Flip Flop...
by lucar
30 Nov 2018, 16:31
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

I would check if a key is really sensed by locating and monitoring "AMS Sense AMP"chip outputs to the respective "Good Depression" and "Good Release" one shot logic.
I would also check that the 25kHz clock is healty.

Image

Luca
by lucar
30 Nov 2018, 00:23
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Actually it's starting to make a little more sense to me now (well, with my mountain of assumptions). My hypothesis at this point is that there is a problem with the sensing on the backslash key. I think that when the flyplate is touching it, it should not be going up and down like that it's doing....
by lucar
29 Nov 2018, 21:28
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

there are two oscillators on the pcb (see block diagram at page 5-47 IBM 5100 MIM) one is 25Khz the other one is 10 hz, I would start searching for those. If You follow the POR Reset signal from the keyboard connector, You'll end in a Flip Flop which output drives an AND logic that ANDs the OSC outp...
by lucar
29 Nov 2018, 18:50
Forum: Gallery
Topic: Chinese 3-Color Dye-sub AEKII
Replies: 5
Views: 2035

This is fucking awsome!
by lucar
29 Nov 2018, 13:32
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

snuci wrote: Just so yo guys know, I am soaking the Logic Manual. It is a pack of schematics that I can hopefully get apart. There is a keyboard schematic in the bunch but it looks moldy, unfortunately. Let's see what happens.
That would be AWSOME!
by lucar
29 Nov 2018, 09:00
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

With one apparently working key, I would investigate slash, Power On Reset POR , Keyboard Lock and Typamatic combinations. Did You?

One more thing to sort out is why the thing needs an 8.5v input . Can you trace it on the PCB?
by lucar
28 Nov 2018, 21:14
Forum: Keyboards
Topic: Olivetti ANK 2463 / Olivetti Personal Computer Keyboard 1
Replies: 21
Views: 37781

Nice looking. How much this keyboard worth ? As usual with these oldies that's relative. There are people that are willing to spend quite a bit on something like this. On the other hand you may get lucky and pick one up for cheap. I looked on Ebay and Amazon and can't find any of this keyboards Her...
by lucar
28 Nov 2018, 18:24
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Oh! On page 5-24 of the "IBM 5100 portable computer Maintenance Information Manual" https://www.slideshare.net/LeonHenry/1970s-manual-ibm there is a block diagram of how the main board handles the various parts of the assembly. If you need searchable manuals, please go to my site here: http://vinta...
by lucar
28 Nov 2018, 16:05
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Also , on page 5-47, there is the internal keyboard logic block, it looks to me that Keyboard Lock gates the Kbd0-kbd7 register...

And POR should be just a pulse to reset all the logic.

Luca
by lucar
28 Nov 2018, 15:55
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Oh! On page 5-24 of the "IBM 5100 portable computer Maintenance Information Manual" https://www.slideshare.net/LeonHenry/1970s-manual-ibm there is a block diagram of how the main board handles the various parts of the assembly. If You read carefully the schematic , it seems to me that: a) Kbd Strobe...
by lucar
28 Nov 2018, 15:33
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

can You press the 'C' key so that we can compare the effect against @snucis table? Right now I don't get anything when I hit any keys (except for backslash). I was checking voltages on the individual ICs and noticed that some aren't getting any power. Would this suggest a bad capacitor? I traced th...
by lucar
28 Nov 2018, 10:39
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

can You press the 'C' key so that we can compare the effect against @snucis table?
by lucar
27 Nov 2018, 16:09
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

I think the addressing is not an action that occurs at the keyboard I/O level, but rather at the "BIOS" level. I.e. a piece of software would use the keyboard bios address to "address" the keyboard and read the data latched when the strobe is received. If you look at page 3-11 in the maintenance ma...
by lucar
27 Nov 2018, 15:43
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Oh, and You have to pay attention to point 2) of the guide " the selection of a device address then makes the data available on the bus in bits lines " So the 5110 keyboard should worlk like this: a) a key is pressed and released b) a "scan counter chip or circuit" records the keycode in an internal...
by lucar
27 Nov 2018, 15:27
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

I took a look to the "maintenance guide for the 5120 available on bitsavers" that You mentioned and on page 2-76 there is the Z4 socket pinout You published.

Is Z4 the "I/O card adapter" mentioned? If so , strobe and (parallel) data from the "scan counter chip" are there...

Luca
by lucar
27 Nov 2018, 15:11
Forum: Workshop
Topic: IBM 5110/5120 keyboard conversion
Replies: 75
Views: 19731

Hi! I'm not an expert nor I know anything about Ibm 5110 keyboards but this reminded me the description of the internal working of keyboards given in the 1977 book "Microprocessor Interfacing Techniques (Sybex)" by Austin Lesea and Rodney Zaks. I have the 1980 italian version of the book. http://mir...
by lucar
23 Nov 2018, 20:26
Forum: Workshop
Topic: IBM 5251 restoration (rebuilding phase)
Replies: 50
Views: 14822

You are going strong man! :)

Luca
by lucar
22 Nov 2018, 11:20
Forum: Gallery
Topic: Wang 725 retrobrighted
Replies: 12
Views: 3450

Really a nice job! Thanks

Luca
by lucar
21 Nov 2018, 19:19
Forum: Gallery
Topic: Wang 725 retrobrighted
Replies: 12
Views: 3450

deeyay wrote:
snufflecat wrote: Nice work. How long did you leave it in the peroxide?
Around 12 hours =)
With UV , sunlight..?

Luca
by lucar
21 Nov 2018, 19:14
Forum: Keyboards
Topic: Wyse PCE Space Bar
Replies: 9
Views: 2564

Hi, I have 2 Wyse PCE and one Bull Questar that is just a Wyse keyboard rebranding. Your spacebar is too noisy but it is quite normal in untouched Wyses. The spacebar stabs are pcb mounted , I did Superlube them as I lubed the stabs at the spacebar joints. My spacebars have the same noise of the res...
by lucar
19 Nov 2018, 13:32
Forum: Workshop
Topic: Televideo - The beginning of a journey. The end of my social life.
Replies: 89
Views: 20689

I got this in the mail today: https://i.imgur.com/Rc1YWFI.jpg https://i.imgur.com/XgUOhQD.jpg https://i.imgur.com/dJ1HLke.jpg https://i.imgur.com/g4tO0vq.jpg This is one of the Televideo 965 boards from snacksthecat, it's in like new conditions and he did a wonderful job converting it. I'm very happ...
by lucar
19 Nov 2018, 08:24
Forum: Other
Topic: (Free/Raffle) Election Day 2018 - "Your vote, your keyboard."
Replies: 79
Views: 114988

Better than having more cables around I guess.

Luca
by lucar
17 Nov 2018, 10:32
Forum: Gallery
Topic: Post your desktop.
Replies: 1834
Views: 550369

tron wrote: My setup for 2018. I'm currently using the dual Cyrillic/English 3278 I restored earlier this year.

Restoration link- https://imgur.com/a/D1XHKll

Extra shots- https://imgur.com/a/8Hewqjj

Absolutely gorgeous!! Congrats!

Luca

Go to advanced search