Does anyone know anything about this typewriter interface?

The typewriter is an AEG Olympia ES-95i. It's a big beige electronic machine from maybe the late 70s or early 80s.

On the back there is a 20 pin rectangular male connector with 2 rows of 10 pins. If I connect random pins with something metal, it types various characters. I'm wondering if anybody knows what kind of interface this thing might use so I can go about connecting it to my computer.

I've found a bit more random information about this type of device which might help:

Apparently Olympia made another typewriter in the same line that was basically the same as a bytewriter model. Irritatingly the article says the bytewrite provides no technical information "other than the pin-out assignments for the connector. "

It would appear from the rest of the article that the connector might be some kind of modified centronics interface.

I'll try to get a picture up soon.

Here's the photo. Whatever it is I hope it turns out to be bidirectional so I can use this as a tty :).

Picture of Does anyone know anything about this typewriter interface?
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andrew823 years ago
Hi. Not sure it's still actual to you. Found this interface among things of my wife's mom.  
Let me know, if interested.
Olympia Interface 1.1.jpgOlympia Interface 1.1.jpgOlympia Interface 1.1.jpg
metroelect6 years ago
I was an Olympia Dealer in the 80's. I have parts and manuals. The port you are talking about is for a spell check options. it plugs to the logic board on the left side ST10 and usually connects to a serial or parallel or speller option. the data bus on ST10 is D0 - D6 is on 2b thru 8b and D7 is 10a R/T on 5a gnd on 7 & 8a 5volts on 9b 9v on 1a power reset 6a inverted fehler 4a dack 10b inverted drdy 1b inverted reset 9a oc 2a 3a inv inverted the data bus buffer is is14 a 74hc245 the processor is a custom 3870 contact me if you need more.
these typewriters are real work horses. I kept mine for a xy plotter or something. The two circuits for vertical and horizontal drive 36 volt motors. the port you are talking about is straight off the processor and data bus. i would love to hear what you build!
kelseymh8 years ago
[ Before anyone else posts, "Just Google It" is the wrong answer in this case. There doesn't appear to be any sensible information, like owners' manuals, out there. ] That connector sounds like a "standard" Centronics parallel interface. If you can take a picture of it and attach it to this question (use "Edit" under Author Options), it would make this problem much easier to solve.
pharoah (author)  kelseymh8 years ago
Attached the image for you.
Any chance of emailing me the image, I have the same typewriter, and am trying to build an interface for it.

Many thanks.

Thanks. It definitely isn't "Centronics." It is, however, a standard ribbon cable card-edge socket, which would take a connector like this.

Unfortunately, as you have guessed below, the pin-out is likely to be proprietary. I've just tried a search for Olympia "ES-95i" connector (using pin-out gave zero results).
pharoah (author)  kelseymh8 years ago
One thing I did was to take a ribbon cable in my junk box and cut it until It had 20 pins and it would fit into the port, so that I'll have something to interface this with when i find out how. Since the web search isn't bringing up anything direct, I looked into the pin-out of the standard centronics connector and it seems like if you were to combine all the grounds into 1 wire it would be 20 wires. So, assuming that this is some kind of centronics port, is there a way I could test the pins with a computer/multimeter/something else to find the pin-out myself?
I'm going to promote my actual response to you up to a top-level "Answer", so that you can flag it and close this thread it if turns out to work :-)
. hmmmmm I don't remember ever seeing that type of connector used on the "outside" of a printer.
pharoah (author)  NachoMahma8 years ago
I think it probably went with some kind of proprietary cable. It's behind a little cover in the back, although I've really zoomed in on it so it's hard to tell.
. I searched for ES-95i +cables and +adapters and came up empty handed. Are you sure a ribbon wouldn't fix the problem - I can find LOTS of those. :) . That looks like the same style connector as used for things like HDDs and floppies, ie, a standard connector. If you can ID what it's called, that may help in a search.
In a discussion below, the author asked,
I looked into the pin-out of the standard centronics connector and it seems like if you were to combine all the grounds into 1 wire it would be 20 wires. So, assuming that this is some kind of centronics port, is there a way I could test the pins with a computer/multimeter/something else to find the pin-out myself?

You can if you have an old-style "parallel printer port" on your computer. If not, things probably get more complex and you need adapter boxes and whatnot.

The difficulty will be knowing which pins on this unknown connector map to which pins on the standard 36-pin Centronics-style connector. Without a pinout that may be impossible. If you're willing to disassemble the typewriter temporarily, you could consider (and laugh) folllowing traces from the connector and try to deduce which ones are control lines and which are the eight data bits.

You can purchase (I needed one for an old Epson printer) converter cables to take you from a Centronics-style connector to a DB-25 parallel-port connector. Then you'd need to wire up your 20-pin ribbon cable to the mate of the Centronics connector on that converter. Once you've done that, just plug it in and try sending some plain text to LPT1:.
pharoah (author)  kelseymh8 years ago
My task today will be to try to take this thing apart so I'll be looking for any kind of part numbers I can find and, failing that, try to trace all the connections. My eeepc doesn't have a parallel port, but I have a few printer cables, a connector from an old printer I can wire to, and an old PC-AT that I won't miss too terribly. I can try writing some GW-BASIC programs to test my interface once I've built it. The trick will be finding the power and strobe lines I think.
. An oscilloscope would be a big help for reverse-engineering the signals, but not in most DIYers tool box. . Don't forget some kind of current limiting, in case you try to send a ground high or power low. Your computer will probably protect itself, but the old printer isn't likely to be so forgiving. . . Keep us posted. You have piqued my curiosity. Sounds like you've done the same to kelseymh. ;) If you come across any interesting terms, maybe we can help you with the searches.
johninst7 years ago
I have a similar problem - I believe the interface is 5volt ttl logic, but I have not got any more info - has anyone found out any more?
Trevcharl8 years ago
Dont even try tace the tracks on such a pc board, just look at the numbers on the chips. 8250 will be a serial to parl converter, for instance, then look up the numbers. If there is a serial to parl converter then its a serial input, if there is a 8 way buffer, then its a parl input. The numbers can be identified if you google "Semiconductor devices" digital. Pinouts Even numbers ground (standing next to each other. 1 - Strobe, 3 to 17 are Data 0 to data 7, 19 Acknowlege, 21 Busy. You will see that the sequence followed is the same as the parl port on the DB25 male connector that plugs into the computer. Use a multimeter, measure resistace between adjacent pins, if all are very low like .2ohm, then thats the earths the even numbers. If your rows are only 10 way each, the might have taken the last earth i.e. 20 for the busy signal. If you measure 20 to 18, you will get something like 22K ohm, then thats the case. Buy a ribbon cable header, 20 way ribbon cable, and a DB25 male. The header is easy, line up the wire so they fit into the tiny forks, and squash the cover over the lot. The other end will have to be soldered wire by wire. Make a table oin x on header to pin y on DB25, before you start, you wont make a mistake then. I dont guarantee that this is the correct connections, but it is probably going to work, for most manufacturers stick to this sequence. cheers trevcharl
Trevcharl8 years ago
I had a very old Centronic printer with that connector. Its called a ribbon cable header socket, and it was the input from a serial port. The board it plugged into was a serial to paralled converter with a bit of memory for a printer buffer. One could remove this board and plug in a parallel cable from a PC. If you have not get any joy yet I can look see if I can find the pinouts of these connectors. I keep a record of everything! Cheers Trevor
pharoah (author)  Trevcharl8 years ago
Well I've pulled apart the machine but I haven't found any better clues and I'm not good enough at hardware to trace the tiny traces. If you can find the pinout spec that would be massively helpful. I haven't given up on this project, just been away for 2 weeks :).
NachoMahma8 years ago
. My first guess is that it's a parallel i/f with a Centronics connector.
. Another possiblility is an RS-232 serial i/f, but those usually have an odd number of pins, eg, 25, 15, & 9.
. The manual for the printer should tell you for sure. Google is your friend.
Hi, Nacho. I tried both the obvious and a series of less obvious Google searches. The manual for that typewriter is either not available online, or it's available in a way that Google doesn't know about it.
. Dang! I thought I was going to get to show you up with my l337 534r(|-| 5ki11z, but all I find is ribbons. . I'm still betting on parallel/Centronics. . And, yes, a picture would be a BIG help.
pharoah (author)  NachoMahma8 years ago
I wouldn't have posted here if it were easy to find on Google :).