I could have sworn we just discussed this very topic, complete with pictures including one of this very cable, i.e. a 40-pin IDE/PATA cable with a one-piece two-sided dual-row pin header inserted at one end (also used to convert the pinout of an M100 cable with a 'normal' DIP plug).
Apologies if the pictures weren't clear enough... m ----- Original Message ----- From: Brian White To: [email protected] Sent: Tuesday, October 24, 2017 10:13 AM Subject: Re: [M100] DVI cable Yeah that's what the home-made T102 cable that came with my dvi looked like. A regular ide cable with the middle connector still on, and a bunch of pins jammed into the connector on one end to make it male. A proper pin header would make a pretty neat "no building" answer, except for not being keyed to force the right polarity. -- bkw On Oct 24, 2017 9:27 AM, "Stephen Adolph" <[email protected]> wrote: for what it is worth, I seem to recall being able to use a standard IDE HDD cable, with a long pin header for T102 <--> DVI. maybe I recall incorrectly though. On Tue, Oct 24, 2017 at 9:07 AM, Brian White <[email protected]> wrote: My new cable is like you say on the right. ---- For instance: * The Model 100 tech ref http://www.classiccmp.org/cini/pdf/Tandy/Model%20100%20Tech%20Reference.pdf page 28 (also the service manual http://www.classiccmp.org/cini/pdf/Tandy/Model%20100%20Service%20Manual%20(Final).pdf page 35) Says AD0 is pin 3 on the 100 * The DVI service manual http://www.classiccmp.org/cini/pdf/Tandy/Disk%20Video%20Interface%20Service%20Manual.pdf page 70 Says AD0 is pin 6 on the DVI ---- Similarly, I've now built a T102 cable with the twists. https://photos.google.com/share/AF1QipMkzQNqSYNaG6XGROBssfEmXJ5kj3-Kv-gOHMuqPQJdSUloL8ZpSs83D-tcocw8jA?key=ZzRJQnlPVXlsRVZJVGE1ZXlKdkpoYnlvTUh0NjhB * The T102 tech ref http://www.classiccmp.org/cini/pdf/Tandy/Model%20102%20Tech%20Reference.pdf page 20 Says AD0 is pin 5 on the 102 And sure enough, this cable constructed this way, pin 5 on the T102 end goes to pin 6 on the DVI end. This cable visually matches up with the old ebay one too, which we can only assume was good. (I didn't buy this cabel, just downloaded the pics while the ad was still up) https://goo.gl/photos/Sm8xx3Ys2vJwpQYu7 ---- To me this corroborates the M100 cable, because it shows that both cables deliver the same signal to the same pin at the DVI end, and I think there is no argument about how to make a T102 cable, and this T102 cable also appears to agree with the tech references. Everything is consistent with everything else. This also reasserts my initial idea that they designed the DVI pinout specifically to accommodate the fact that the DIP connector connects pins-to-wires in a different pattern than than regular IDC connectors, specifically to allow a flat simple cable using a DIP connector like that, and why the T102 & 200 needs twists. I've now tried both my M100's and my T102, and none of them are booting my dvi, but by now, I actually think it's a problem with the dvi even though these cables are both new and unproven. The pinouts check out with the manuals, my new T102 cable also agrees visually with those pics from that old ebay item for a T102 cable. I got my dvi off ebay and never saw it actually work, nor did the seller claim it. -- bkw On Tue, Oct 24, 2017 at 1:00 AM, Mike Stein <[email protected]> wrote: I must admit that I'm starting to get confused myself but unless I hear otherwise I'm going to stick with my original opinion (Oct 17) that the DIP pin 1 should connect to the IDC header pin 1 which would connect DIP 29 to header 24, not 23. Sounds like your cable connects DIP 1 to Header 2 etc. Correct ? Yours? DIP IDC DIP IDC 1 1 1 2 2 3 2 4 3 5 3 6 4 7 4 8 5 9 5 10 6 11 6 12 7 13 7 14 8 15 8 16 9 17 9 18 10 19 10 20 11 21 11 22 12 23 12 24 13 25 13 26 14 27 14 28 15 29 15 30 16 31 16 32 17 33 17 34 18 35 18 36 19 37 19 38 20 39 20 40 21 40 21 39 22 38 22 37 23 36 23 35 24 34 24 33 25 32 25 31 26 30 26 29 27 28 27 27 28 26 28 25 29 24 29 23 30 22 30 21 31 20 31 19 32 18 32 17 33 16 33 15 34 14 34 13 35 12 35 11 36 10 36 9 37 8 37 7 38 6 38 5 39 4 39 3 40 2 40 1
