Yes, the RS printer cable was just a 26-wire ribbon cable. The high lines are ground as you would expect so you have ground lines between signal lines. Not only can the M100 not send out parallel data that fast but the printers it was used with were slower yet.
Jeff Birt From: M100 <[email protected]> On Behalf Of B9 Sent: Monday, July 13, 2026 5:50 PM To: [email protected]; Peter Noeth <[email protected]>; Model 100 Discussion <[email protected]> Subject: SPAM-LOW: Re: [M100] Ideal length for M100 printer cable? Radio-Shack's six foot printer cable was unshielded and untwisted? I wouldn't have expected that to be reliable. Am I overly cautious? Or was it perhaps only meant for very low speeds? Did Radio-Shack at least ground every other wire in the ribbon to reduce crosstalk? --b9 P.S. Probably not relevant, but I wonder if the level of background electromagnetic noise has changed in the last fifty years. On July 13, 2026 2:33:37 PM PDT, Peter Noeth <[email protected] <mailto:[email protected]> > wrote: Jeff, If I remember my "70s mini-computer days" correctly, the normal max length for Centronics Printer cables was 12'. This was with the round cable, consisting of 18 "twisted wire pairs" (one wire signal the other wire ground), that was then shielded with an aluminum foil wrap and a bare ground "drain" wire connecting it the full length to the metal shells of the connectors. Doing the same with simple flat "ribbon cable" I would expect that Radio Shack's 6' length would be the maximum, as they tested functionality with that length (but not FCC compliance). Radio Shack used that cable for all of their computers, with the "business machines" usually connected to a printer on a floor stand, so the 6' length would be appropriate, and for connecting a "home computer" with an Epson MX-80 size printer on the same tabletop, the cable would just drape down behind the table. But for portability with the M100 (or T-102 / T-200) I would think a 3' cable would be better, especially if you use its original TRP-100 printer (or some other portable printer of similar size), as it would be more convenient to roll up the cable to pack in a computer bag. The one I made to use with my Seiko DPU-414 printer is 34" long. For me this is long enough to use the computer in my lap while watching T.V. and have the printer sitting on the end table. Regards, PeterN On Mon, Jul 13, 2026 at 1:10 PM <[email protected] <mailto:[email protected]> > wrote: Message: 1 Date: Sun, 12 Jul 2026 18:56:53 -0500 From: [email protected] <mailto:[email protected]> To: [email protected] <mailto:[email protected]> Subject: [M100] Ideal length for M100 printer cable? Message-ID: <[email protected] <http://soigeneris.com> > Content-Type: text/plain; charset="us-ascii" Hi all, I had someone ask about acquiring an M100 printer cable a few weeks ago and was surprised how much they were going for on eBay. I have an original cable which is 6' long, which is a bit too long, I think. I picked up some Centroincs connectors and just made a 3' one which is fine for sitting the M100 next to a CGP-115 or larger printer but perhaps not for having the printer sitting away from the M100. What do you think the ideal length is? 3', 4', 5', 6' or perhaps just offer then in either 3' or 6'? Jeff Birt (Hey Birt!) <big snip>
