I built my North Star Horizon in 1978 and used it for years. Eventually I updated the cpu, fdc, and RAM boards. I still have the system and have been trying to revive it

After the utter disappointment you suffered with the 70s Trinitron, it's so good to see (and share) your delight in getting this beautiful machine running. Very well done. +1

The Hazeltine 1500 was one of the first low-cost smart terminals, from a company with a rather interesting history. Most 5.25-inch floppy disk drives won't spin up without a control signal.

The memories. My high school had one of these terminals. It was connected to a computer that had a couple of 8" FDD and a card reader. It had stopped working. I fixed it by setting up the dip switches properly. Someone must have messed with them. It was a buzz for me as a 12yo to 'fix' such a big computer that no one else at the school could.

Brilliant! There's a Hazeltine 1500 sitting on the shelf right next to me, waiting to be cleaned and restored. My unit has the anti glare screen coming of in pretty much the same way as yours. ;)

When you were taking the CRT out you held it by the neck… that’s a really good way to break the tube. You should always hold it by the body of the tube and be VERY careful to not hit the neck on anything - they are quite fragile, and essentially unubtainium now that nobody manufactures them anymore.

Boy this takes me back. I was a cop in a small North Dakota city, the locals learned somehow that I was also a computer geek. Suddenly my phone would ring as I was trying to sleep, and my wonderful wife was working at the local nursing home, some business would be having computer troubles, this in the late 80's. I worked with C= machines but these folks were using early IBM, Epson's and such, so I learned how to work with CPM and DOS as well. Now my C=128 came with a version of CPM so I played with that to get to know the language, our city Judge had an Epson running CMP and he helped me get into it as well, he didn't know much about it except how to load his software but that bit helped. One fellow had a 10 MEG external Hard drive that was HUMONGUS and weighted a TON. He sold his machine to the Newspaper but the monitor was gone, so the paper owner had me go up in his store room and print out a database of all citizens and farms that the old business had gathered to use for his plat book. Man talk about a hot noisy job but I got it done, and as a reward the paper gave me the machine, after all he just purchased it for the data. Ah for the good old days when only we few knew how to work these mysterious magic boxes!

A paperclip is usually the correct size to fit in db25 and de9 ports

I recently acquired a keyboard module from a North Star Advantage. The key caps are gorgeous. They are the favorite of all I own. It's foam and foil, though, which isn't everyone's cup of tea.

The yoke looks to be slightly twisted after the reassembly. Just type a full line of text and twist it to get the text perfectly level.

We had one in the local library. You could book time on it or the MIcroBee. Dearly wish I could find one for my collection. Love this.. they're not easy to find any more :)

When the Hazeltine 1500 was market current, about the time I was attending University of South Florida in Tampa FL, it was very common for terminals to be positioned in rooms with anti-static flooring and pretty intense air-filtration. By the time personal computers like the Apple II and IBM AT were starting to edge out mainframes, you started seeing a more lackadaisical placement of computer hardware and the grime inside the case could get to fire hazard levels. In the mid-1980s, at Marshall University in Huntington WV, I saw quite a few Hazeltine terminals that were hooked up to the university's VAX mainframe and they were all approaching end-of-life from hard use and poor (if any) maintenance. Over the years, I've seen melting of the sealant on old CRTs and terminals pretty often. Something in the chemical composition of the sealant causes it to go all tarry after about 20 years, well past the expected lifetime of the hardware. A good deal sooner if the component has been stored in a situation without rigorous climate control like the manufacturer expected "back in the day". I don't know if Northstar ever had compilers for PL/I, Cobol, Fortran, Basic, and Pascal, but I do clearly remember doing an ungodly amount of coding in PL/I, Cobol, Fortran, Basic, and Pascal on Hazeltine terminals. :D.

Good Grief; that capacitor is the size of a can of soup! The only ones that I can think of are bigger are the ones in Tech Tangent's Data General and the ones in early television sets, which were like shoeboxes.

Great video. Love those vintage PCs. Thank you

Kentucy Fried Comptuters: "A computer in every pot". I don't know who came up with this marketing but it's genius.

Captive screws, or bolts, would have increased the likelihood of this model being able to compete for contracts for equipping ships or air crafts. The terminal looks really nice. I feel really good, watching this on a Sunday morning, eating toast, drinking coffee while also hanging up my laundry.

Great Video! especially enjoyed seeing the Terminal/Monitor restored

That's pretty good that you have a working system, and terminal, with relatively little work needed. Very nice.

CP/M wasn't a clone of DEC RT-11, but it certainly drew inspiration from it. And RT-11 was influenced by earlier DEC operating systems for the PDP-8 and DEC-10. Windows use of forward slashes for command line switches and CR/LF line separators for text files can trace their lineage through MSDOS and CP/M back to DEC.

I used this system connected to a hard disk while I was at college learning how to program in cpm. I can remember fixing one as it blew its tantalum capacitors. If I owned it I would add crowbars to power supply rail's.

Definitely want to see more from this computer, hope you can get those drives fixed.

That’s a big milestone. Well done mate.

This thing reminds me of an old Heathkit H89 computer I picked up at a church garage sale years ago. It also used hard-sectored disks, and it could boot both CP/M and HDOS as its OS. A special latching key on the keyboard would essentially disable the CPU and let it act as a dumb terminal. I wish I still had it, it'd be worth a fortune now.

I did my computer college course on this baby, loved it. A Microline 83 Printer was connected. Had a Microtan 65 at home. Loved the early days of computing.

Not sure that was pure silicone. If it was, mineral spirits are your solvent. The problem with that is that it works so well you wind up smearing liquid silicone all over the place. I usually try to manually remove it if I can. Lighter fluid is Naptha, also available in larger volumes at your local paint store. Works a charm on stickers and adhesives in general and if worse comes to worse, pour some in your zippo and set it on fire.

exciting! i like the simple mechanical fix for that transformer

That keyboard sounds so nice.

Beautiful minicomputer! Very jelly.

That's a beautiful terminal.

Excellent video. I was expecting at least one Tantalum cap to pop though! N* used some particularly explody ones on their boards :) If you have no luck after cleaning the drives try checking/swapping the LF356 Op-Amp in the top left of the disk controller board. I've had to swap these on three of my MDS-AD3 boards after they showed very similar symptoms as yours.

Great progress!

11:52 That an 8080 running the terminal? That's hilarious... The Z80 replaced the 8080 in mini computer systems because it required fewer support chips and only 5v... But the freakin terminal is controlled by an 8080

I am currently trying to fix a Northstar Horizon that I acquired a year ago. I'm still struggling to get any output from it. I think I need to get one of those chip testers because I think something on the IO side of things is not working, or I do not have the correct boot disk. The lack of output from the system if no disk is found makes it hard to diagnose.

Great video! I think we need more on these systems that happened right at the beginning. I would love to get one of those terminals and just plug a Pi into it and simulate a PDP11 or something. 😁

It's an interesting mix. 70s electronics, 80s aesthetics, 90s (simulated) tracker music. I dig it.

32:55 DQ, aside from being tasty, is probably "dual quad" disk drives, quad capacity being North Star's term for double sided/double density. On their later Advantage machine, the CP/M herald would show 2Q or HQ depending if it was a hard disk system, for example.

Well its good to see it boot up, even if there are still a few issues. As I am sure you've already found, those drives will probably benefit from being stripped down, cleaned and re-lubricated as drives decades younger suffer from dried up grease!

Seeing this makes me appreciate what we have now more.

Really nice vintage machine you got there.

You either run regular DOS or extra crispy DOS.

Dude! Like the guy who is Arctic Retro is your flipping TWIN.

For color CRT the anode is 27kV typical and for the monochrome CRT the anode should be 15kV as far as I can remember.

Another good goop remover is VM&P naptha, which is very similar to lighter fluid.

I remember my brother using a Commodore Pet to do some real computing, not only playing games or writing endless loops in BASIC.

sticky is the heat degradation from humidity the cold issue can also be ram if its below 62F

I remember that computer and the S100 bus.

All that effort to do a loopback test. Back when I was repairing dumb terminals, a paperclip was often the preferred tool for loopback testing!

But can it tell me the 11 herbs and spices 🤔

so did you just leave the screen gasket at the end or rebuild it? Always interesting hardware and stuff in your videos, really like it. Lot's of practical tips and even some history as well ;) Keep up the good work!

First computer I ever used! Hadn't a clue and reformatted the hard drive and turned in into a brick!

very good video

Unless you've got an analog alignment disk, don't even attempt to align them, you'll just make the drives unusable. Chances are pretty high that the root cause of the disk problem is lack of lubrication in the head transport mechanism.

Someone using lighter fuel for cleanin. Instant thumbs up!

Wow! I bought one of these in the early 90's, (steel case) including a large 12" 10MB (or20?) HD that I planned on using as a turntable mechanism. Still has some of the cards and the disc on the wall, I never got it running, but I got it for parts anyway. (didn't have a terminal, but could use my Amiga as one.) edit: It might be a 14" disk platter, I cannot find 12" but 14" seems to be a standard. I platter in a huge cast aluminium chassis with a clear lid. Butchered a long time ago, but still kinda cool!

about 30 years ago I had a Basis 108 computer that ran either CPM or Apple Basic. it was a desktop, heavy and massive, wish I had held onto it, just because I code in basic and that would be all it would be good for, that I know of. didn't have any other software for it, and it did not have a Hard drive, that I remember at least. but I could still get blank 5 1/2 in, floppy disks back then. got alot of enjoyment out of coding on it.

Actually, MS bought SCP lock-stock-and-barrel. Also, CP/M would want you to either pull the system disk and then insert the disk to be formatted, or you could specify to format the disk in the B: drive.

One common problem with S-100 buss equipment is the failure of one or more voltage regulators that are present on each card. That's a common place for a short to develop. The buss voltages are unregulated, and the cards are more or less responsible for regulating what they use. For this purpose, regulators of the 78XX family were common.

Great video! How does the RS232 loopback help print characters to the screen when typing? I can't figure out how that would work, I was too young when these computers were in use.

The HORIZON was my dream computer in the day… but then I went to work for DEC !

I'm going with "teen" over "tine" like Ovaltine, solid guess. ^_^

Being the KFC computer, DQ surely means Dairy Queen.

FYI, the C-64 & Apple II didn't use the index hole at all.

I learned two new things from you today about computers. After 40 years. Thanks. DQ, F KFC.

Dynamic file allocation? Bah! Hard sector floppies, baby and you knew where every byte was. -grizzled old Northstar Horizon owner.

Boot address is E800...There is a rom on the disk controller at that address. Disks are hard sectored... in other words a BUNCH of sector punch outs...and a few bunched together for sector 1. (I wrote drivers for printers and the like back in the dark ages. NS Dos had a 256 byte region that you could fit the drivers into.... There is no built in monitor...so you have to boot a floopy to get anything...

Did the broken flyback bolt go through the middle of the winding?.. If so it's probably a good idea to fix it back in the hole with some silicon or hot snot or whatever.. it's part of the transformer tuning (actually critical). These have a habit of failing on 70's Trinitron TV's and invariably kill the flyback.

i hear wd-40 is stronger than wd-30

Oh wow T-Slim, what canullas do you use?

First DOS for microcomputers. You could store 90 Kbytes on one single diskette.

What happened to the disk drive repair video?

Those old computers surely were well-built.

Hit ^g on loopback and you should be able to make that speaker sound. (Ctrl-g is ASCII 7, or “bell”)

We used these in college along with a whole lab full of Commie Pets.... Had an Apple ][, a trash 80 and some other weird and wonderful machines..... IIRC the CP/M COBOL compiler would crash if you had a bug in your code....

I know there's a KFC that made monitors back in the day. Sadly, not this era AFAICT-VGA monitors, not terminals.

We had one of these in school with 4 screens and 4 keyboards. You had to write your programs to print to your terminal. 10 Input Q 20 Print#Q"Hello World" 30 Goto 20 You could have fun writing messages to the other screens with a for next loop then clearing them away. This and a Commodore Pet were my introduction to computers. Many Thanks to Mr. Todd who used to open the computer room up for me before school, I learned a lot and it changed my life.

Now i am imagining that someone theew their laptop in to the kfc frier

Captive screws ❤❤❤❤

We used Hazeltine 1500 in the computer lab when I was in school. I have heard it pronounced both ways, but I am pretty sure that it is 'Hazel teen'

This terminal has a separate processor - Intel P8080. Or did I see badly?

Mmmmmmmm woodgrain

CRT monitor look even better if you use a polkarizing screen cover

Yeah, I prefer WD40 because it doesn't eat into plastics. You can leave it sitting and usually just wipe it afterwards. The smell is really nasty for some time though. On glas your method or acetone should do the trick since you would hardly hit any plastics. To finish I prefer spiritus based window cleaner (Frosh in Germany f.j.)

I believe it's pronounced Hazeltine. WD-30 is definitely better than WD-20, but I'd still go with WD-40. In all seriousness, that is a cool machine and I wish computers were still built as well. After watching DIY Perks I've been thinking of building a case entirely out of wood. Get some brass sheet metal, either walnut or mahogany.

Woodgrain 🤤🤤🤤

that one is probably around 11 to 16 Kv

More Questions About S-100 Computers ? www.s100computers.com

But will it run Cyberpunk 2077 or RDR 2 ?

MS DOS was originally IBM PC DOS. But for whatever reason(s) IBM chose to sell it to Microsoft.

Acetone also works

Maybe try WD-40, this WD-30 seems like a cheaper knockoff =P (Joking of course)

led is probably 3.3v

Love the content, but I can't hear you properly over the music.

all 5..25 inch disks have the index hole... it's there to tell the drive where sector zero is... whether it's hard or soft sectored doesnt matter :D

Everytime you wave your hand around the computer's power supply or the terminal's CRT, I can't help but physically cringe.