<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>So the NUD4273… From:</div><div><br></div><div><a href="https://www.usenix.org/events/lisa00/full_papers/drzyzgula/drzyzgula.ps">https://www.usenix.org/events/lisa00/full_papers/drzyzgula/drzyzgula.ps</a><br></div><div><br></div><div>—-</div><div>It contains fifteen resistors, eight diodes, three transistors, one op amp and five capacitors – one of them a large 1000uF electrolytic.</div><div>—-</div><div><br></div><div>Finally found a picture:</div><div><br></div><div><a href="https://web.archive.org/web/20010614020819/http://www.nudata.com/pdf/4273_Sellsheet.pdf">https://web.archive.org/web/20010614020819/http://www.nudata.com/pdf/4273_Sellsheet.pdf</a></div><div><br></div><div>Man I’d love to be able to clone that.</div><br id="lineBreakAtBeginningOfSignature"><div dir="ltr">Sent from my phone</div><div dir="ltr"><br><blockquote type="cite">On Oct 16, 2023, at 6:50 PM, vom513 <vom513@gmail.com> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><span>Hello all,</span><br><span></span><br><span>So I have a couple of dumb terminals (the one I’m using to test now is a WYSE-160). I’m using an IPX as the test machine. So this has the DIN-8 to DB25 cable.</span><br><span></span><br><span>As we all know, by default, when dropping the console connection (i.e. turning the terminal off) - Suns will drop to PROM/debugger :(</span><br><span></span><br><span>Years ago there was supposedly a pricey cable/dongle (NuData 4273) that would “shield” the Sun from break signals. Another hardware solution I’ve seen mention of is putting a resistor in the connection to disable break signals. This is the rabbit hole I’m going down.</span><br><span></span><br><span>I’m trying to use this:</span><br><span></span><br><span>https://hea-www.cfa.harvard.edu/~fine/Tech/cs1.2/Sun-serial</span><br><span></span><br><span>According to that, we are pulling -5v off pin 25, running it through a 4.7k resistor, and connecting this to pin 3 on the Sun side ? Am I reading that correctly ?</span><br><span></span><br><span>On my IPX - I seem to get nothing off pin 25 (testing with DMM, and tried the shield as well as pin 7 as ground).</span><br><span></span><br><span>I do however seem to get -5v off pin 1. If I’m reading that Harvard URL right - I should be able to use pin 1 in place of 25 ? I’m leery of this as I’d really rather not blow up the serial port and/or machine itself…</span><br><span></span><br><span>So any info anyone can give me on this would be greatly appreciated. I’d really like to be able to power my dumb terminal off/on as well as use a serial switchbox without dropping the box(es) to PROM.</span><br><span></span><br><span>Thanks.</span></div></blockquote></body></html>