I think many of us would be happy to see some images of your work. I don't ask for a manual, that would be very time-intensive, but if you could make some photos - that would be gr8!
Thanks! Pawel On Friday, 9 July 2021, Justin Poirier wrote: > My first run was using a 28C256 on a SOIC-28 chip. Same thing you did, I > used a resistor to hold /WE so that I could pull it with the burner when > I wanted to erase/re-write the image. But, also like you said, those > chips are $10 each now and hold a single image. I built the carrier > (actually, designed in KiCAD and sent to GoldPhoenix for fab), soldered > the SOIC on and burned it using a DIP-28 to "Molex" adapter that I built > out of Cat5E wire and a DIP header, with 1" long "fingers" on the other > size made out of gold-plated spring wire used for craft jewelry. The > carrier clips into that 28-pin finger arrange, which has all the pins > for a 28C256 DIP-28 re-mapped to the Molex pinout and the burner just > sees it as a DIP-28. Works pretty good, but it's a pain, and it's expensive. > > So the PROM version uses a AT27C020 in PLCC-32 format on a different (of > course) carrier, and via a suite of programs I wrote in Perl, builds a > single ROM image out of 8 32k images, which I burn in the TL866-II. Then > I solder the chip to the carrier, and the DIP switches select which > 32-image is available at any given time. Simple enough, and it works > very nicely. I have several of my prototypes in my T102 and several > T200s. No complaints. The chip is $4 at Digikey, and as long as I get > the image right, it's one-and-done. > > This is a working project. It's done, except for the actual ROM images. > I have the boards fabricated, the chips on hand, and have a half-dozen > working prototypes on my bench. I know the REX is a great device, but > sometimes K.I.S.S. wins out in my head. Sometimes I just need a ROM in > that slot all the time, and since I have a good number of Ts that are > all used in various ways, I can't justify putting a REX in each. > > --Justin > > On 7/8/21 3:19 PM, Brian K. White wrote: > > On 7/8/21 10:06 AM, Justin Poirier wrote: > >> It appears that Club100 on bitchin100 only have a handful of ROM > >> images. Where do I go to find SuperROM, Disk+ and those others? They > >> have generic enough names that Google has been of very little help. > >> > >> I have been working on an inexpensive carrier solution (for myself, > >> mostly) that will hold (8) ROM images that are selected with a group > >> of DIP switches on the carrier itself. Nothing fancy, but if I like > >> the results, I could probably crank them out, burned and ready, in > >> the $20-$25 range. Not committing to anything at all, since I’m still > >> in prototyping, but with (8) ROM slots, I’m not sure what to put in > >> them. So far, I made one that has TS-DOS, Ultimate, Cleusseau and > >> TS-Random. And since I have twice as much space as all that, it > >> includes those titles in both the M100/102 versions as well as the > >> M200 version. That seems wasteful. Maybe I’m wrong! > > > > How are you connecting up to burn them? Through the edge connectors > > with a reverse pinout adapter? DIP-28 test clip on the outside edges > > with the wires arranged into a reverse pinout adapter? Or are you just > > burning before soldering and no re-writing after that? > > > > I made this single-rom carrier that, since it's an SOIC package, and I > > have a resistor rather than a trace for /WE, is easy to just connect > > normally with a soic test clip to program. > > http://tandy.wiki/Teeprom > > > > > > But that 28C256 is now OVER $10 just for a single 32k, and I'd like to > > try to ditch the requirement for the test clip if possible, and > > definitely don't want to require an actual Molex socket. (I have molex > > sockets, but I'm trying to make a design anyone can use, not just > > something for myself) So I tried this > > https://github.com/bkw777/Teeprom/blob/master/Teeprom2.md > > > > 4 or 8 roms (that's just a 4-rom version but 8 would be a > > straightforward progression from there) and no special parts needed, > > and it's even both cheaper and more convenient than the soic-28 test > > clip, and the flash part is both more readily available (multiple > > manufacturers still) and just over $1 instead of over $10. > > > > > > Which *almost* works as envisioned. The programming adapter is built > > out of all normal off the shelf parts, and the connection between the > > programming adapter and the carrier is made by dint of having the > > holes on the carrier be offset staggered so they work against each > > other. I think I just need a different stagger pattern, and slightly > > more offset to the stagger. I was able to get it to work by tediously > > testing each pin for connection to identify a handful that didn't > > connect, and bending the pins manually until they all worked. > > > > Not practical. > > > > But that was only the first proof of concept, no iteration yet, so > > maybe with a little dialing-in the idea would work out. > > > > But then again maybe that many little pins in that kind of arrangement > > is just never going to be reliable. > > > > So I was thinking of next either using pogo pins, because those are > > actually cheap now, or using long wire-wrapping pins to make something > > that can act like a DIP test clip that can just contact all the edge > > contact pins on the outside like a normal socket does. That would make > > the carrier a LOT simpler! > > > > I really thought those pins were slick ;) If they would just all > > actually make contact, it does pretty much work as expected, meaning > > it wasn't too hard to build and that carrier pops right onto the > > programmer simply and even with polarity enforcement. > > > > > > I've gathered links to all the roms I've seen here: > > http://tandy.wiki/ModelT_roms > > > > Most you can get all in one spot from Steve's REX docs on bitchin100 > > (link in there), but there are a few other oddballs. > > > > Documentation has not been gathered into one convenient spot that I > > know of, other than club100 which is a good start but incomplete, and > > not going to get any better, it's a static site now just being > > presereved. > > > > You get info from searching through the M100SIG > > https://archive.org/details/M100SIG > > , club100, scanned magazines on archive.org, and general google for > > info on other vintage computer sites. I don't have a link farm handy > > to list those. > > > > -- Kind regards / Mit freundlichen Grüßen ExPLIT IT Soltions Pawel Radomychelski
