Hi, I have an FTDI converter, bought it to connect the M100 to modern stuff without real RS232 ports. But I was trying to get ppp to work on the PI-Psion connection and I was trying everything possible (and it still doesn't work) under linux. I can get it to work on Windows but that sort of defeats the whole purpose of having something small bridge between the Psion and today's internet. I really only wanted to get mail to work so I didn't have to type on the phone or tablet screen but maybe a small bluetooth keyboard is the answer. If I keep the mail on the pi I guess I can use any terminal to do mail, like the M100 or the Psion but the M100 keyboard is better.
How to configure ppp to work is still a mystery but that is really not the subject of this list. Tried slirp and even found a number of people that claimed it would work but it doesn't work for me and it doesn't want to compile on my linux machine, either. Jonathan jonathan.y...@mykopat.slu.se ________________________________________ Från: M100 [m100-boun...@lists.bitchin100.com] för Tom Wilson [wilso...@gmail.com] Skickat: den 21 september 2020 22:06 Till: M100 Mailing List Ämne: Re: [M100] definition of null modem Some tips on that.... Are you using Linux on the Pi? If so, it would be easier to just use a USB serial port. The Prolific and FTDI ports both work with Raspbian; I've used both. Otherwise, maybe look at a DTE wired level converter with CTS/RTS.... like this one: https://www.amazon.com/NulSom-Inc-Ultra-Compact-Converter/dp/B00OPU2QJ4/ref=sr_1_4?dchild=1&keywords=ttl+rs-232+level+converter&qid=1600718673&sr=8-4 Although I'm not sure where you'll get CTS and RTS on the Pi. I don't know that it's mapped to any of the GPIO pins. This might help a little bit: https://www.raspberrypi.org/forums/viewtopic.php?t=241623 Tom Wilson wilso...@gmail.com<mailto:wilso...@gmail.com> (619)940-6311 K6ABZ On Mon, Sep 21, 2020 at 12:10 PM Jonathan Yuen <jonathan.y...@slu.se<mailto:jonathan.y...@slu.se>> wrote: Hello, I actually am trying to connect a Psion 5MX with it's 'serial cable' to a raspberry pi, the serial lines on the GPIO thing. The pi is TTL, so I have an adapter to change it to RS-232. The adapter is DCE, but the Psion cable actually terminates as DCE, since it was made to plug into the serial port on your PC for synchronizing etc. The Psion has a perfectly good comm program, so I'm using it as terminal (there is even a VT100 program) but I need the 'null modem' or crossover connector to connect it to the level-shifter. Since they were both female, I actually did the test with 3 pieces of maybe 14 or 16 gauge insulated wire, maybe 3 cm long, with their ends stripped and pushed into the right holes. But I thought I should have something a bit more 'robust' and maybe do the other lines as well. I think Psion actually made a modem that connected to this cable, but that must have been DTE....... I guess I always thought of the 'modem' in null-modem as 'modem=DCE' since I've always connected DTE things together. But I appreciate the feedback from the group. Jonathan jonathan.y...@mykopat.slu.se<mailto:jonathan.y...@mykopat.slu.se> ________________________________________ Från: M100 [m100-boun...@lists.bitchin100.com<mailto:m100-boun...@lists.bitchin100.com>] för Tom Wilson [wilso...@gmail.com<mailto:wilso...@gmail.com>] Skickat: den 21 september 2020 20:18 Till: M100 Mailing List Ämne: Re: [M100] definition of null modem "Null" means "none" or "zero." So "null modem" means "no modem." This term is an adjective and should be coupled with "cable", "adapter", or some other noun to be of any use. I don't see a need to re-define the term, since "null modem cable" is well established, and we all know exactly what the term means. Strangely, there are times you actually need a null modem cable to connect a computer to a modem. Most CP/M computers used dumb terminals, as did any mainframe and minicomputer (also called a mini mainframe.) Since those computers were designed to have DTE devices plugged directly in to their terminal ports, you might need a null modem cable to connect a modem to the mainframe... Of course, in that case, we'd just call those "modem cables" (or, more commonly, the 8-pin modular to DB25 adapter would be labeled "modem".) So in that instance, we literally used a null-modem cable to connect to a modem.... Sometimes I love the English language. Tom Wilson wilso...@gmail.com<mailto:wilso...@gmail.com><mailto:wilso...@gmail.com<mailto:wilso...@gmail.com>> (619)940-6311 K6ABZ On Mon, Sep 21, 2020 at 9:16 AM Lee Kelley <l...@3footed.com<mailto:l...@3footed.com><mailto:l...@3footed.com<mailto:l...@3footed.com>>> wrote: I've always thought "null modem" was a misnomer. It probably should have been called a "non modem cable" or simply a cross over cable as mentioned above. On Mon, Sep 21, 2020, 11:06 RETRO Innovations <go4re...@go4retro.com<mailto:go4re...@go4retro.com><mailto:go4re...@go4retro.com<mailto:go4re...@go4retro.com>>> wrote: On 9/21/2020 10:59 AM, Jonathan Yuen wrote: > > That said, I could only think that the other wiring should be same as a null > modem, but I thought that I should air my thoughts to see what other people > think. I'm curious about the use case, but you are correct, the wiring would be the same. Maybe, (though no one will do this, as the other terms have been in use for too long), it's best to call such a cable a "crossover" cable, like is available for Ethernet ports. Jim --- När du skickar e-post till SLU så innebär detta att SLU behandlar dina personuppgifter. För att läsa mer om hur detta går till, klicka här <https://www.slu.se/om-slu/kontakta-slu/personuppgifter/> E-mailing SLU will result in SLU processing your personal data. For more information on how this is done, click here <https://www.slu.se/en/about-slu/contact-slu/personal-data/> --- När du skickar e-post till SLU så innebär detta att SLU behandlar dina personuppgifter. För att läsa mer om hur detta går till, klicka här <https://www.slu.se/om-slu/kontakta-slu/personuppgifter/> E-mailing SLU will result in SLU processing your personal data. For more information on how this is done, click here <https://www.slu.se/en/about-slu/contact-slu/personal-data/>
