An excellent repair and restoration job! Thank you for rescuing another machine from the garbage dump.

all home computers should still look like this I say :-) Such an iconic look from the 1970s!

50% of people selling stuff on eBay have no clue how to properly package it. I have taken to asking them before bidding if they are familiar with packing heavy, delicate things before shipping. Someone who takes pride in the effort they put into packing something will be happy to tell you what steps they take. Those will no clue will be offended you asked.

@paulmoscatt6529

2 жыл бұрын

It's not hard to ship a TRS-80 computer or expansion interface. Shipping a monitor is much more difficult to do properly. Even worse since they are way more delicate now with brittle plastic and age as when they were new.

@RS-ls7mm

2 жыл бұрын

@@paulmoscatt6529 The first expansion interface I got from eBay was broken in shipping. Almost no padding. Not as bad as the heavy old HP power supply I got that was wrapped in one layer of bubble wrap. Some people don't realize that shippers just toss the packages around. The ones with high sell count are the best bet.

I loved your video (restoring one myself right now) but *please* folks use plastic screwdrivers when working with CRTs and try not to reach around the back of the yoke from the front when making adjustments. There's over 21kV in that area. FWIW I wear sneakers and insulated work gloves whenever I'm inside a CRT monitor or TV even when it's turned off. Note that the tube continues to hold a significant charge when it's turned off and unplugged.

I had one of these back in the 1970s. The monitor was a custom made RCA television with the tuner board removed.

When I was a kind my Grandfather had this computer, and he use to bring it to my school and wow all the kids and even the teachers with it. That was... very early 80's I guess, amazing how far we have come.

My school's first computer. I taught myself to program in BASIC and we got a lot of use out of it!

That glue (tamiya extra thin cement) is used for building scale plastic models. Its an excellent glue. Never thought about using it for repairing old computers.

Great work! I felt the pain when the computer kept resetting after typing that listing in :)

A quick trick I adopted for working on pinned PSUs like this is to get some thin tubing, cut to a little over the length of the pins. Drop it over the pins and you can slide your probes into the tubes and be confident you'll only make contact with the pins you're measuring. I used to use heatshrink, but I stole the straw off one of those "juice box" drinks my kids like and cut it into lengths. Great for all of these PSUs (and there are SO MANY!)

@DaveGagliardi

2 жыл бұрын

That is a fantastic idea! Thanks for sharing that!

Beautiful computer 🙂

Really enjoyed watching. Looking and replacing the chips, my heart fluttered. One of my greatest fears.

I remember debouncing a large number of these. They changed the keyboards on the later models, to one from ALPS, and they had a software routine to fix the repeating keys. To fix the problem in hardware, remove the key caps, and look at the contacts inside. There are four on one side, and one on the other. Gently bend one of the four slightly inward, so that the first one to make contact is the last to break contact. You may want to use some contact cleaner as well, but, after fixing at least several dozen of these, I never found it necessary. If you feel particularly fussy, you can adjust three of the four contacts, again making sure that one definitively makes contact before the others. Replace the key caps, and enjoy your bbbbouncccceee-free keyboard. If you check online, you should be able to find the lowercase mod, that simply adds an extra bit to bring the video memory up to 8 bits. The character generator chip already has lower case, it’s just missing the last bit.

my first computer

I remember brining one of those home in 1979. I added the expansion cabinet, Modem & the Floppy drive before it was all over.

Thanks for sharing. I'm always impressed by how methodical you are in your repairs.. most of us would skip the little things and just be happy it worked. It's always great to see when someone goes the extra mile.

Great video. It's a great feeling when you turn it on the first time after a repair and it works. I just finished a Coleco Adam with a bad CPU and video processor. Also have one of these with an expansion interface. Love these trash 80s!

I suspect that this unit has not seen a lot of use back when it was new and since. Almost all of the model 1's had the silver paint on the front edges of the unit wear from just a a thousand hours or more of use.

Great video. Perfect background entertainment for me today. Thanks!

My friends dad had a model 1. I really wanted a computer when i saw it playing some text version of space invaders. Good times

Excellent work and video as always. I feel your pain. I get a TRS80 model III and it was completely destroyed. It had to got o e-waste. Sad day

Very cool! Nice work! I would really like one of these for my vintage computer collection, but I don't have any more space!

Would be nice to go through an upgrade path... 16K, expansion interface, disk drives... cool video. My first computer was a 4K level 1.

The cassette mod isn't necessary if the Level II ROM set is new enough. They actually fixed it in software in the 1.3 release so the hardware mod was no longer required.

@HutchCA

Жыл бұрын

Yes, I forgot that they fixed it in firmware. I was just surprised since I had another '79 model 1 with numeric keypad that had the XRX mod and this one is a '78 but perhaps it was upgraded to Level II later.

Very nice my friend

It's a shame the seller didn't use any bubble wrap or foam to protect this classic machine. The chip PIN straightener you used on the video RAM chips are awesome! They come in handy with new/replacement chips for sure! On your cassette recorder service, where did you order the belts from? Also, that 303 protectant is amazing! Nicely done on your model 1 restoration.

@geekwithsocialskills

2 жыл бұрын

@@HutchCA Thank you for the link. Again great job on your #SepTandy video!

@RudysRetroIntel

2 жыл бұрын

Excellent work and video as always. I feel your pain. I get a TRS80 model III and it was completely destroyed. It had to got o e-waste. Sad day

@ernestgalvan9037

8 ай бұрын

@@geekwithsocialskills…the link to the belts has disappeared . Did it age out? I’m working on a Realistic cassette machine, the high-end ‘soft-switch’ stereo one, and it needs belts.

Nice video. I had a model 1 level 2 back in the day, and I seem to remember that the level 1 could be upgraded to a level 2 but that also included the 16K of RAM and a numeric key pad. Weird yours said 16K level 2 on the expansion port, maybe it had a new case from a level 2 machine.

Huh, that's really strange that you'd have so many dead video RAM chips without much in the way of other problems. Congratulations on the final product, although, yeah, the seller deserves to be slapped. Over on my channel I just completed my own repair of a bedraggled eBay TRS-80 (that I *thought* had a video circuitry problem but actually turned out to be something much more global in scale) and, man, it's kind of shocking to me how nice and simple your factory-stock 4K machine is to deal with inside. (That is a weird config, though, 4K but Level II!) My example has multiple "power user" hacks with switches running to holes drilled in the case, a CAS/RAS/MUX DIN pigtail for the old bad E/I, the "sidecar" numeric keypad, etc, and I had the *worst* time getting that monster back into the case when I was done.

Loctite is very effective. Just a few drops.

@HutchCA

Жыл бұрын

Loctite is a brand name. I assume you mean CA adhesive but that is very problematic since it can overflow and cause significant discoloration. Acetone is simply a solvent that dissolves the plastic, and if it overflows, as long as you don't touch it, it will just evaporate leaving no trace. It's much more effective at welding the plastic back together than CA glue which dries brittle.

Awesome Subbed you

It looks like the QC inspectors wrote their initials and date of inspection on the keyboard. Is that what's written there?

Straight acetone works wonder on ABS plastics, its possible to make a repair that is almost perfect, i.e not showing.

19:10 Good news ... you don't have lice! I haven't finished watching so you may answer this here, but I think that when my junior high school upgraded from 4K Level 1 to 16K Level 2 we got a numeric keypad too. Was that a common option, or am I misremembering?

I found the technical manual for Radio Shack Service Centers online. It lists all the parts and shows the schematics. I wonder if someone could actually rebuild one from scratch using this book.

@HutchCA

2 жыл бұрын

It's been done. Google "glen kleinschmidt TRS80"

Hi, congratulations for the video. Could you please tell me the name of the tool to tighten the pins of the chips and where can I find it? Thank you!

@HutchCA

10 ай бұрын

IC Pin Straightener. I got it from Jameco. Part # 99363. Manufacturer p/n: ICS-01-R

@byteretroone

10 ай бұрын

@@HutchCA thank you 😉👍

Where did you get those video ram chips? I just bought a trs 80 Model 1 and the same issues.

@HutchCA

Жыл бұрын

I got the 2102 RAM from Jameco. Specifically MM2102AN-4L. Looks like they still have some in stock now.

Hi Chuck - My Model 1 has the same wiggly-screen on the edges of the picture - I assumed it was caps in the monitor, but have not attemted to repair yet. Have you checked any further on this problem with yours?

@BartWillems1969

2 жыл бұрын

Could it be just "cheap CRT?" I remember ours would get squigly like that whenever the screen contained a lot of white pixels.

I'm repairing a model 1, one of the rubbery spacers dried out and crumbled when I pulled it off. Do you have any suggestions for a replacement? Also, I found rubber feet adhered to the inside of the case. I wonder if this was done in the factory or if the previous owner did this....

@HutchCA

Жыл бұрын

I think I found rubber feet inside also. Maybe they were there to keep the boards in place. No ideas about the spacer rings. Anything the right size should do it. Maybe a stack of O rings?

@paszTube

Жыл бұрын

@@HutchCA I'll figure something out. Whatever works, it's on the inside of the case so no one will see ;). Thanks for the reply.

@paszTube

Жыл бұрын

@@HutchCA I saw the rubber feet inside the case on a video by Adrian's Digital Basement as well.

You should upgrade that to 64K I remember back in the day when 64K was so much money. Now you can buy the chips for pennies.

@lohphat

2 жыл бұрын

48K was the max amount of RAM due to the lower 16K was reserved for ROM (12K), video RAM, and reserved memory-mapped ports.

@ernestgalvan9037

8 ай бұрын

@@lohphat..old video.. for future. The main unit (keyboard) held a maximum of 16k RAM, as you state that the lower 16k was reserved. The other 16k was added via the ‘Expansion Module’. Although, yes, nerds had their “RAM-BAM’s” that was a board that hacked in the 16k inside the keyboard…. Rat’s nest, and I didn’t like it.

Shipper needs to be thwapped repeatedly with 2x4.

Should not insert the chips into the sockets until AFTER they are soldered in!

@scharkalvin

2 жыл бұрын

@@HutchCA sorry, I guess you were just putting the sockets into the board. Hard to tell as camera work wasn't perfect. IIRC the model I didn't have lower case, which would explain why only 7 video chips. MSB must be used for cursor and graphics.

@scharkalvin

2 жыл бұрын

@@HutchCA I expected an extra bit would be needed for inverse video on a character by character basis.

thats disgusting ....packaging ...