The Centurion MicroPlus: A First Look (Part One)

[@UsagiElectric]

Excellent to see and can't wait to get up there and get hands on with this thing! Some extra info on the mysteries of the terminal. The unmarked key is just "New Line" again, no clue why it's a different plastic or even blank, but functionally, it's just "New Line". The AUX port on the back was a way to hook up a printer, I think it mirrors everything received to the printer or something like that. I've never used that port so not 100% on it. The DIP switches do look correct. It's set for 9600 baud and Even parity, which is on point. Centurion defaults to 9600-7-E-1. Interestingly, it looks like it's set to 20mA current loop instead of RS-232. The MUX card (depending on revision) on the Centurion can handle both, so it could work just straight out. Just gotta find the right cable to match up to the Centurion's MUX pinout! For self-echo, the Regent 100 had it, but the Regent 40 didn't. You can emulate that by taking a little piece of wire and connecting pin 2 and pin 3 on the RS-232 plug. Though, you'll probably need to flip the little DIP switch to set it to RS-232 mode for that to work. It's a good way to test that the terminal is largely functioning though. Email incoming, we're going to hammer down a date for me to get there for sure!

[@JosiahGould]

I had a feeling you'd pop up here. I'm glad to see these obscure systems being dug up and brought back to life.

[@a_Fax_Machine]

It's so cool to see a community pop up around such an obscure part of computing history from 50 years ago. I binged David's videos on the Centurion systems he has over this past winter and can't wait to see what's next

[@russellhltn1396]

You can emulate self echo by just switching to half-duplex.

[@russellhltn1396]

Think of the AUX port as a A/B switch for the main connection. The computer could either be connected to the terminal itself or the aux port. The most common use was for a printer for the user (the terminal wouldn't be useable during printing). But it could be something like a barcode reader or any other device that could talk to the computer.

[@kenromaine2387]

@@russellhltn1396 A few Centurion customers would connect a serial printer to the AUX port on the ADDS terminal mainly when the terminal & serial printer are "remote" over a single phone line & MODEM likely at just 1200 baud ( back in the early 1980's). The good part of the remote terminal attached to the MODEM and the serial printer (like a TI-810) attached to the AUX port is you only have the monthly cost of one phone line & MODEM from the local phone company. The bad part is when the printer is printing you can not use the ADDS terminal for data entry. If you had open ports on the 4-Port MUX in the MicroPlus and could afford a 2nd phone line and MODEM bill for the serial printer then you could have the printer running & do data entry on the ADDS at the same time.

[@Kae6502]

Usagi sent me. Subscribed. Can't wait to see more on this system!

[@kenromaine2387]

The ADDS Terminal keyboard used the Cherry Key Switches in the keyboard. I bet the white key next to [Return] seem to be a replacement key cap replacement. (( Notice my company Centurion ring ))

[@93sr20det]

Great to see you here Ken.

[@WC0125]

GREAT! Glad to see another Centurion saved from the scrap! It will be great to see it working again. I sold supplies for Centurions back when they were in first generation service. Their maker, Warrrex, was a Texas firm and marketed Centurion to small energy producers during the late 1970's domestic oil boom. Centurions became well known with oil and gas companies out here in the west. When the bust started in 1982 our area became a ghost town. Shortly thereafter I was seeing Centurions (and other similar era systems) sold for pennies on the dollar at bankruptcy auctions. Some ended up at the local college for electronics technology majors to hack and scrap. At one point, in about 1989, the college had collected donated systems to include a complete Centurion like Usagi's, a Wang System 5, a IBM System/32, mounds of PETs, and various DEC PDP-11/?s. All mostly working and complete with peripherals, tape drives, hard and floppy drives and with mounds of software and documentation. Now it's just a memory. It would be nice to have that stuff around today for your museum.

[@bennetfox]

Eeee I love Used Cars!!!! Such an awesome B Flick!!! Did you know that was Kurt Russell's first movie?

[@TheHylianBatman]

Aw man I was very sad when the video ended! I've been catching up with Usagi Electric for ages, so it's great to see more Centurion! I can't wait for David's video, or visit!

[@RetroGamingNook]

Great vid as always. Those colors remind me of the ball returns at the bowling alley back when I was growing up. Interesting system, sorry to here it was terminal. 😢

[@sdsck]

Excellent !

[@raymondjett]

Hey Vintage Geek! Usagi Electric will be at VCF Southwest at the end of June. Come on down to Dallas.

[@horusfalcon]

You can't go wrong collaborating with David from Usagi Electric. When it comes to Centurion, he has done a lot of heavy lifting to get where he is knowledge-wise on the Centurion, and on electronics in general. I wish you both the best of luck with the MicroPlus!

[@kenromaine2387]

In the video at 8:04 the [ Line Mode ] dip switch is show (Half=0)=Local Echo the keyboard to the CRT screen and also XMIT to the computer, (Full=1)= do not Echo to the screen just XMIT to the computer. FYI = 1 is Down & 0 is Up and you must power OFF then ON the ADDS terminal to re-read the dip switch setting. When connected to the MicroPlus normal operation is [ Line Mode = Full ] and 9600 baud & Even Parity.

[@n2nby]

@7:50 didn't notice all the help about local echo. "I edited my message out". I can help with testing the RS232. Using a thin piece of wire short pins 2+3 on the main port. Hit some characters and the terminal will local echo. Seeing double mode "half", seeing single "Full". See nothing the port is bad. Bad port could be the line drivers (1488/1489) chips located close the 25 pin ports. After seeing more of the video, I noticed a dot phosphor. Not good, there is a chance the monitor will not light up. Horiz/Vert drive maybe bad. Dot only stays in the center. Not all lost. On the inside is a 14 pin ribbon cable going from the bottom board to the monitor above. Carefully ensure the ribbon is seated in the sockets (monitor n PCB). Might get the monitor to work. That cable never really seated solidly ever. Could be bumped out. 4 screws hold the top cover. The 14 pin ribbon is accessible. If it's tight. Two screws hold the main PCB in place. The electronics were meant to be "Works in a drawer". Take the screws out and slide PCB out. Don't pull out to far, just enough to get to 14 pin ribbon. Be careful the keyboard (Keytronics) 40 pin cable attached. The ribbon is made using PVC plastic, and maybe brittle by now. Good luck.

[@edgeeffect]

The Regent 40 (shape wise) always really reminds me of the Intertec Superbrain CP/M system... I'd love to see the two side-by-side one day. Auto-echo can easily be "faked" by poking a paperclip in the RS232 port from pin 2 to pin 3... that way you're looping TX to RX and - bingo! - local echo.

[@shaunmerica]

Oh man! you got to get hold of Usagi Electric.

[@applesushi]

I’m beyond excited that this is very near to me. I will plan a visit soon!!

[@dave4shmups]

Fantastic video! I’m looking forward to future videos on the Centurion!

[@n2nby]

The company I work for 17 years made than terminal "ADDS". Except for phosphor burn on the tube, looks to be in good condition. Little hint to help the terminal last longer. Never snap the power on and off. If you have to recycle power turn off, count to five. Then turn on again. There are no replacement parts, only others sold for parts. If you could find them.

[@vintagegeek]

Thanks for writing us!! Now I have an unrelated A.D.D.S. question that you might know with your history there...when I was a kid my grandfather would occasionally bring home 'junk' that local stores were throwing away for me to play with...I found this picture that actually shows the terminal I was remembering, which definitely appears to be a Regent. There's a plate on it that says either PSI or P51 or something to that effect (a bit too grainy to tell for sure)...happy to share the picture with you if you send us an email: [e-mail]

[@lawrencedoliveiro9104]

That’s my standard rule every time I power-cycle _anything_ .

[@kellingc]

it's really cool seeing a group come together over a piece of hardware like this. I'm excited to find out more as you explore this system. I've been following Dave's journey restoring the mini computer and would like to see what th3 micro has to offer, too. Some things I'm interested in, what processor is being used; Intel, Motorola, or one designed in-house to Centurion? Is there a common micro operating system like CP/M or a UNIX like system, or a custom system built from the ground up? What us the bus architecture like? Is there any DMA or ISA compliant interfaces? This is an exciting find, and I look forward to watching more as you explore this.

[@JanBruunAndersen]

In-house, custom designed CPU using what is known as bit-slice CPU-components. I do not remember the name of the company that produced these ALU's (Arithmetic Logic Unit), that you could then connect together to create your own fully-fledged CPU. Centurion was not alone in this, it was a common practice among mini-computer companies at that time. Data General with its 16-bit NOVA and 32-bit MV system certainly did. And yes, a very custom and proprietary operating system to go with the unique CPU.

[@kellingc]

@Jan Bruun Andersen Sounds like what Digital Equipment Corperation did before they designed the PDP 1, building logical units that you could connect together and build a computer.

[@kennethflorek8532]

@@JanBruunAndersen Usagi said AMD bit slices on his channel. At the time, chip companies recruited second source companies as a way to assure their customers they had an alternative to arbitrary price gouging and shortages. Intel and AMD had this mutual contract. Intel never fulfilled on the deal, leaving AMD in a bad position. AMD eventually needed to pivot to survive and mainly produce Intel designed dies. Intel did ultimately sue AMD, successfuly putting AMD out of that alternative business.

[@Christianpreaching]

Interesting to see my comments at the 2:53 mark. Small world, or I'm doing too much KZbin

[@georgemaragos2378]

Hi, another great video Totally of content to the hardware, are you aware of any IBM XT/AT software that works similar to a mini set up, eg the IBM has the host program / data base , and you can use the comms ports to open up a link to the PC / host / server and do transactions we point of sale . access database enquiry hmm like a library or video rental setup or something similar I have a 486 with 3 or 4 comms ports and probably 5 other machines with comms ports, using a terminal emulator or comms package it should be fun

[@GamingWithUncleJon]

You could do that with SCO Unix, PC BSDs, or older linux distros. Linux and the BSDs need 386 or newer, and 486 support was dropped from the linux mainline in the last few years so that's why I said older. I'm not as familiar with the BSDs but they still support some really old stuff like VAX.

[@georgemaragos2378]

@@GamingWithUncleJon Hi, Thank you for that, i have a small collection AT's to Pentium 4 with legacy ports, i should dust of the cobwebs of quick basic and Turbo pascal and make a something. Lan parties are a thing of the past but we still do pizza & TV, sometime we do a doom setup, but i thought for a change we can replicate some server host setup with serial I will try concurrent dos 386 or real 32 - i did purchase novell dos back in the day as i had a daily limit to access games on my pc when it was schooldays for the kids - 745 and 755 warning message went to all pc's . then 8pm the shared folder for games was disconnected Thanks again George

[@MarquisDeSang]

I hear a trombone playing in my head.

[@pizzasteve]

Did you rob usagi?

[@kennytrampos7409]

The car dealer clips were too long and annoying .. otherwise great video

[@cdl0]

Here from Usagi Electric: Interesting content, but I don't like the music.

[@nicks4597]

childish movie shorts suck