Trying to justify my purchase of this big old printer

I'm dealing with a bizarre issue trying to print on this ImageWriter II from the Orao... Orao has a very basic serial output for printing (which is why I ended up building a whole serial card for it), but it should be able to TX with DTR/DSR hardware flow

However, no matter what I do, I can't get the printer to respond. I know my baud is set correctly on both ends and I know the Orao is outputting

I even hooked up a terminal onto the same connection and it gets the output from the Orao. Weird

If I connect that same terminal, with same settings, to the printer, I can output just fine. What gives??

Ha it looks like the signal coming out of the Orao printer port is lower than what my terminal sends. So I guess it's too week for the printer?

Interestingly, this is similar to another issue I had with the PHI2 line on the Orao, where I had to amplify it for my serial adapter

What would be a proper way to do this? Last time I took the signal through a NAND gate, twice, but it felt like a very improvised way to achieve this

I guess I could drive the signal through a MAX232 but that feels so redundant since it would require a whole board and 4 capacitors.

I'm just very annoyed that this doesn't work out of the box.

I was right about this. The Orao outputs RS232 levels that ImageWriter II doesn't like. After taking its TX through a MAX232 (comes in on RS232 input, out TTL output, then jumper into TTL input and back out RS232 output) the ImageWriter suddenly accepts Orao's output. Might make a little board just for funsies.

Why do this while I have a perfectly capable RS232 board that I spent months designing and troubleshooting?

The RS232 printer output is built into Orao's ROM, and there is at least one text editor designed to use it. I don't want to rewrite this historical software, I want to play with it 🙃

Proof from Orao's only text editor: TEKSTED

Yay flow control works too, I can print the code for my terminal emulator program

(Yes that would be wasteful but also fun??)

Elon would love this, I'm such a great programer I can write so many pages of code (the gibberish is ASCII that the disassembler can't parse)