any report on keyboard quality versus the model t? I really appreciate this timely thread because I've been looking at the WP-2 of late.
All best, Nick > On Nov 15, 2020, at 9:29 PM, Brian K. White <b.kenyo...@gmail.com> wrote: > >> On 10/15/20 10:13 AM, Josh Malone wrote: >> That sounds awesome, Brian! I'm excited to build one of these once the >> PCB is ready. > > The RAM version is now verified. FINALLY > > The ROM version is not verified yet. I think I may actually just have a bad > chip or a bad solder on this first one I just built, because the pinouts look > ok. I'm getting good chip ID and able to read 256K of data if I try to read > the chip. But when trying to write it says bad chip id sometimes, and > sometimes writes fine but the verify fails and shows no actual data was > written. > > But I don't think the rom version is of much use yet anyway because I don't > think we know exactly what to put on it anyway. I plan to experiment on that, > after I have a card that works. But right now, we have no rom image to load > onto it, it would only be useful for the purpose of starting to figure out > how to make a rom image in the first place. > > The RAM version is immediately and directly useful. > > The RAM version still has an issue merely that it's difficult to build > because of the diodes. They are too small, and the markings that are supposed > to be on top to indicate the polarity are too faint to actually see, even > with light and magnification. The tiny size is actually tolerable, just > tweezers and magnification and patience, but it's annoying not being able to > tell which way to install the thing and having to actually test with a meter. > > But if you can deal with that, it works now. It only gets better from now by > finding a more convenient diode. > > > There are actually 2 versions of each card, a full size pcb that doesn't use > a 3d-printed carrier, and a small pcb that snaps into a carrier. > > I've decided the 3d-printed carrier version of the RAM card doesn't make any > sense and I'll probably remove it, at least from the readme. Maybe leave the > kicad files there off in an extras/junk directory. The small ram card has no > room for a battery, just a cap, and the cap only gives about 10 minutes of > memory life. All along I wondered "why did they even make a RAM card? What > good is a card that erases as soon as it loses powwer?" And then I saw a scan > of a catalog ad that said the ram card was battery backed. So they probably > never did make a card that lost it's memory when ejected or turned off, so > there is no point in making one now either. > > And given that, we might as well not bother for the ROM card either. Might as > well just have two simple plain cards with no carrier. Simpler to assemble, > and cheaper to buy the parts. > > Which means might as well remove the model for the carrier too. Too bad I > really like it. :/ > > I have found that PCBWAY allows to publish a "buy this board" similar to > OSHPark. I posted the ROM cards and the programming adapter on PCBWAY, but > haven't done the RAM cards yet. I'll probably get that up in a few hours. > > The PCBWAY boards would be slightly preferrable because you can order them in > the full allowable thickness (1.0 for the RAM card, 1.2mm for the ROM card) > rather than just 0.8mm. oshpark only offers 1.6mm and 0.8mm. Although, > OSHPark's 0.8mm is significantly stiffer than JLCPCB's 0.8mm, so maybe that's > not such a big deal. I don't know what PCBWAY's boards are like yet but they > are on the way. > > So at this point you can wait a little longer for the pcbway review and for > me to find some other answer for those diodes, or if you were impatient, as > of now you could order the pcb and bom currently posted for the RAM card, and > I would only bother with the battery-backed version of the RAM card. > > https://github.com/bkw777/WP-2_IC_Card > > -- > bkw > > Is the flash version able to be written by the WP-2? Or >> is this just for running z80 programs on the WP-2 which you flash >> externally? >> -Josh >>> On Thu, Oct 15, 2020 at 12:45 AM Brian White <b.kenyo...@gmail.com> wrote: >>> >>> The last piece I as waiting for came in today and the ram card works both >>> mechanically and functionally. > >
