Re: Teletype Question ASR33 RS232 adapter
> > Dave - If I understand you correctly you're saying that I need the powerThey appear to be, yes. I was able to locate the similar 11-version doc. I get confused about the secondary lines, etc.
> > control for PDP 8 and presumably pdp 11/05 reader control. I assume you
> > have this in your teletypes as well?
> I modified my teletype for it. I just put a relay in driven by
> the reader run which switched the power to the reader. The official DEC
> mod was a little more complicated but basically the same.
> You should need 6 wires.
> I looked at 1105S_Schem.pdf which I assume I had downloaded from bitsavers
> when I though I was going to look at an 11 on a work day.
> On page 62 (M7260 sheet 12) you can see it has the reader run drive +5
> through a transistor returned to -15 through a current limit
> resistor. The TX and RX are a couple pages earlier.
> PG 139 shows the KL8E serial cable which is the PDP-8 console cable so the 11
> connections should be identical.
>Am I correct that from the connector, wires 4 and 6 connect to the ASR 33 terminal strip, coincidentally, to 4 and 6? Or is 4 and 6 "common" and it does not matter as long as they're connected?
> Do you have the teletype wiring prints and the 11 prints? With those you
> should be able to figure out the connections. If you need I should be able
> to buzz out my cable to see how I have connected mine.
I have been working from the below doc:
but as you can see lines 4 and 6 are not described outputs. I guess they were only worried about the basic "KSR" setup. I guess Request to Send and Dataset Ready lines are used for reader control. I have to check the TTY manual to learn what differentiates these two.
Kind of confusing to a non-engineer. Thanks for your help...other than that I think I have finished everything else. The pdp 11/05 itself holds the bootstrap loader in memory and runs, but there's no response from the TTY as you'd expect with no reader control attached yet.