Unicomp modern versions of the IBM Model M keyboard built iwth the same tooling that made the originals. When living in a flat share I had access to a IBM Model M keyboard the one made for the PS/2 computer. This is one of the best keyboards I have ever used they are built like tanks.
I tried a "buckling spring" keyboard (I think from Unicomp) that was supposed to be the equivalent of one of those IBMs and I was severely disappointed in the electronics. It could not handle multiple keys properly the way a real one would. Basically they had focused completely on the selling point of the springs and neglected to make a usable product.
(I did have a real PS/2 Model M previously, so all I really wanted was a USB equivalent)
The USB HID standard has a limit of 4 keys pressed at once, unless you do fuckery like virtual USB hubs with additional virtual keyboards (which will cause some things to misbehave) there is no way around this restriction without custom drivers (which are also a nightmare).
This has been debunked several times over the years at Hacker News. The standard imposes no such limit; additional HIDs are not required in order to exceed that number of keys; and properly written ordinary HID drivers can handle what is necessary, as it is an ordinary part of the specification to describe the size of the input report and an ordinary part of a driver's operation to decode and process an input report descriptor in order to know how to decode an input report.
To expound on that: The matrix in most PS/2 keyboards only supports two-key rollover (reliable detection of two keys pressed at once). In the case of three+ keys there is a chance for missed presses and other artifacts.
I've used a Unicomp "Spacesaver" for many years and have been very happy with it. Recently I've switched to a ten-key-less keyboard with blue Cherry switches in order to have more space on the desk, and I've got to say that I much prefer the snappy feel of Cherry switches.
I've always been bothered that Unicomp uses the term "Spacesaver" for their keyboard with less trim; traditionally, a Model M Spacesaver refers to a ten-key-less.
The big difference in the feel between buckling spring and MX blues is that buckling spring has a tactile drop where the force suddenly drops off right at the actuation point[1][2], where blues have a tactile bump where the force spikes up right before the actuation point[3][4]. I'm not sure what it's called, but the blues also have a temporary drop-off in pressure in the middle of the return stroke.
Which is better is a matter of personal preference. There's no substitute for actually trying a switch, but actual force/displacement graphs will do a much better job of telling you what a switch feels like than subjective words like "snappy" or "smooth" or "mushy". https://input.club/the-problem-with-mechanical-switch-review...
Very good points! You’re right on all of them. I remember one game shop had a “RealSound” technology that sounded impressive for a PC speaker. Maybe “Mean Streets” was the name.
Mean Streets did in fact have digital audio samples that played out of the PC speaker, and it was a selling point highlighted on the box with a big red sticker: “Real Sound”.
CGA is probably surprisingly easy. Composite out can plug into almost any TV made in the last 15 years, and many monitors. I could see using my Dell 2007FP for something like this; I've already tried it with a C128.
My parents still have a presumably functional CGA monitor in the basement because we’ve never thrown away any electronic we’ve owned. I am sure there are people like that out there.
Gonbes GBS-8200/8220 CGA/EGA/YUV to VGA Arcade HD-Converter PCB allows all types of RGB, EGA, VGA or YUV component signals to be up-converter and display on a 31KHz PC VGA monitor, TFT monitor, LCD display, or HD-TV with VGA connection. No need to set dip switches in order to figure out the specific input frequency as all inputs are detected automatically! A great alternative to purchasing a expensive, heavy CGA monitor.
The "anonymous BIOS" is just begging to be replaced with a copy of the actual IBM BIOS (whose source code is also available), but I guess they decided not to supply it for copyright reasons; on the other hand, they did clone the hardware... I bet it raises all sorts of difficult questions for the IP lawyers.
I recall it being part of the documentation that came with the original PCs.
> IBM published the entire listings of the BIOS for its original PC, PC XT, PC AT, and other contemporary PC models, in an appendix of the IBM PC Technical Reference Manual for each machine type.
Compaq created a new BIOS from a clean sheet of paper design, not a reverse engineered or ROM dump. The code of the BIOS on the PC and PC/XT were copyrighted.
I heard a tale - but can't find an online reference - for the first Compaq PC BIOS containing a bit that said 'Not (C) IBM' in order to pass some software checks searching for the strings '(C) IBM' being present at certain specific BIOS addresses.
userbinator's post clearly mentions cloning the hardware being problematic legality-wise and I was replying to that. Nobody's saying the cloned BIOS is problematic legal-wise.
This is so very tempting, yet I know well I don't have the time or patience to set one of these up. I hope we'll at least see some of these pop up on YouTube, I'd love to watch someone assemble and use one of these.
And after you put it together, remember you need a power supply, a CGA? card and a keyboard to use it (and a DD or HD if you want to do anything besides looking at a screen)
I believe it was possible to use the original PC with cassette tapes instead of floppies, though you'd be limited to ROM BASIC in that case, and not PC-DOS.
> There's a reason why DOS stands for Disk Operating System. :)
This is a retronym. Before purchased by Microsoft, DOS was developed by Seattle Computer Products under the name QDOS (Quick and Dirty Operating System). This was changed by Microsoft to MS-DOS with a changed meaning of "DOS".
That's a pretty kit and that was a very large amount of work, congratulations on seeing it through. I suspect there is a larger market for a more complete offering, so maybe tackle a graphics board next?
I'm amused by the timing of this article. I just watched the anime series "Steins;Gate", and a major plot element revolves around getting a working 5150.
> Obviously, this is a project for an advanced electronic hobbyist and computer enthusiast.
is somewhat tongue-in-cheek: this could be the thing to get a kid who's already soldered together a bunch of (less expensive) analog hobby kits .. or the adult who's into that sort of thing.
it's pretty much the same thing as building model cars, airplanes, etc. although it doesn't teach you exactly how the thing works, the perceptual task of doing the soldering and checking out the traces gives some idea of how things piece together.
as far as vintage electronics go, IBM PCs (probably?) aren't that difficult to find for those who're essentially interested in abstracting away from the hardware.
I use the word "reproduction" because "clone" in the context of the Original IBM PC is/was an ill-defined word which means different things to different people:
When some people think "clone", they think "compatibility" which leads to the following differences:
Excerpt:
"In May 1983, Future Computing defined four levels of compatibility:[11]
Operationally Compatible. Can run "the top selling" IBM PC software, use PC expansion boards, and read and write PC disks. Has "complementary features" like portability or lower price that distinguish computer from the PC, which is sold in the same store. Examples: (Best) Columbia Data Products, Compaq; (Better) Corona; (Good) Eagle.
Functionally Compatible. Runs own version of popular PC software. Cannot use PC expansion boards but can read and write PC disks. Cannot become Operationally Compatible. Example: TI Professional.
Data Compatible. May not run top PC software. Can read and/or write PC disks. Can become Functionally Compatible. Examples: NCR Decision Mate, Olivetti M20, Wang PC, Zenith Z-100.
Incompatible. Cannot read PC disks. Can become Data Compatible. Examples: Altos 586, DEC Rainbow 100, Grid Compass, Victor 9000."
So what type of a "clone" are we talking about?
I don't work for the company that makes the kit, and as far as I can tell prima facie, their kit is a faithful reproduction of the reference IBM PC hardware design.
Very shortly after this article was published nobody was using the term in any way but the top one (nor were less than 100% compatible PCs even sold for much longer).
My parents bought our first “ibm compatible” in 1987 and even back then the degree of compatibility was already a complete non-issue.
I'm not sure if you were alive at the time but an IBM PC "clone" was basically anything with even a hint of compatibility with PC software, no matter how half-assed. I think the usage of the word "reproduction" is perfectly acceptable here. :)
I am quite aware that the clones quickly became, in effect, the real thing. In spite of the way people apparently are interpreting, I meant my comment as a compliment; this system, in no small part because it is a clone, is perfectly in line with the original PC ecosystem.
Unicomp modern versions of the IBM Model M keyboard built iwth the same tooling that made the originals. When living in a flat share I had access to a IBM Model M keyboard the one made for the PS/2 computer. This is one of the best keyboards I have ever used they are built like tanks.
Unicomp keyboards https://www.pckeyboard.com/