Vintage IBM Daisywheel Prints Again after Reverse Engineering

Just before the dawn of the PC era, IBM typewriters reached their technical zenith with the Wheelwriter line. A daisy-wheel printer with interchangeable print heads, memory features, and the beginnings of word processing capabilities, the Wheelwriters never got much time to shine before they were eclipsed by PCs. Wheelwriters are available dirt cheap now, and like many IBM products are very hackable, as shown by this simple Arduino interface to make a Wheelwriter into a printer.

[Chris Gregg] likes playing with typewriters – he even got an old Smith Corona to play [Leroy Anderson]’s The Typewriter – and he’s gotten pretty good with these largely obsolete but lovable electromechanical relics. Interfacing a PC to the Wheelwriter could have been as simple as scrounging up an original interface card for the machine, but those are like hen’s teeth, and besides, where’s the sport in that? So [Chris] hooked a logic analyzer to the well-labeled port that would have connected to the interface card and reverse engineered the somewhat odd serial protocol by banging on keys. The interface he came up with for the Wheelwriter is pretty simple – just a Light Blue Bean Plus and a MOSFET to drive the bus high and low for the correct amount of time. The result is what amounts to an alphanumeric printer, but with a little extra code some dot-matrix graphics are possible too.

Having spent a lot of time reverse engineering serial comms, we can appreciate the amount of work this took to accomplish. Looking to do something similar but don’t have the dough for a logic analyzer? Maybe you can free up $22 and get cracking on a similarly impressive hack.

[via r/arduino]

Filed under: Arduino Hacks, misc hacks

Do You Miss The Sound Of Your Model M?

There is one aspect of desktop computing in which there has been surprisingly little progress over the years. The keyboard you type on today will not be significantly different to the one in front of your predecessor from the 1970s. It may weigh less, its controller may be less power-hungry, and its interface will be different, but the typing experience is substantially identical. Or at least, in theory it will be identical. In fact it might be worse than the older peripheral, because its switches are likely to be more cheaply made.

The famous buckled springs in operation. Shaddim [CC BY-SA 3.0], via Wikimedia Commons.
The famous buckled spring in operation. Shaddim [CC BY-SA 3.0], via Wikimedia Commons.
Thus among keyboard aficionados the prized possessions are not necessarily the latest and greatest, but can often be the input devices of yesteryear. And one of the more famous of these old keyboards is the IBM Model M, a 1984 introduction from the computer behemoth that remains in production to this day. Its famous buckled-spring switches have a very positive action and a unique sound that once heard can never be forgotten.

So if you are a Model M enthusiast and you miss the characteristic clack of high-speed buckled-spring typing on your modern-day laptop, what’s to be done? Fortunately [Ico Doornekamp] has the answer, in the form of bucklespring, an IBM Model M sound emulator. Install it on your Linux box, your Mac, or your WIndows PC, and relive the classic sound of the 1980s as you type!

Yes, it’s gloriously silly, we’ll grant you that. And all your colleagues will hate you for it. But we know some of you won’t be able to help it, and will spend the next few days gleefully clacking away from your MacBook Airs until you get bored with it. After all, if using your computer no longer has the power to entertain, what’s the point?

If the Model M is too new for you, it’s not the only desirable IBM keyboard of yore, how about a Model F? Or give up on these newfangled electronics, and just use a typewriter.

Via Hacker News.

Header Model M image: Raymangold22 (Own work) [CC0], via Wikimedia Commons.

Filed under: classic hacks, hardware, peripherals hacks

Inside card sorters: 1920s data processing with punched cards and relays


Ken Shirriff did an in-depth write-up of the punched card sorter:

Punched card sorters were a key part of data processing from 1890 until the 1970s, used for accounting, inventory, payroll and many other tasks. This article looks inside sorters, showing the fascinating electromechanical and vacuum tube circuits used for data processing in the pre-computer era and beyond.

More details at Ken Shirriff’s blog.

Check out the video after the break.