Mousing ItBy Peter Naulls. Published: 17th Mar 2005, 13:49:05 | Permalink | Printable
Ian Nichols shows the DIY mouse wayIn a recent usenet posting in reply to a query about where to obtain Acorn Mice, Ian Nichols commented that he'd had success modifying standard optical PS/2 mice for use on RiscPCs.
As you may know, Acorn machines from the Archimedes up to the RiscPC have an atypical mouse interface, normally referred to as "quadrature". Outside of Acorn machines, these were also widely used on Sun machines and terminals. Historically, most mice on other platforms were serial, and later PS/2 and more recently, USB. Many mice now available for purchase work on both PS/2 and USB interfaces. PS/2 is also used for the keyboard interface on RiscPCs.
Even at the time of the RiscPC manufacture, the quadrature interface was unfashionable, and the story goes that Acorn only stuck with it because of supplies of components. They later ditched this, and A7000s and A7000+s received a PS/2 interface, as was the norm on PCs at the time.
Still, this left existing users who required a new mouse a relatively expensive replacement option from Acorn. To the rescue came STD, who created a PS/2 adaptor allowing attachment of the growing range of PS/2 mousing options from the likes of Logitech. Later, STD produced a smaller and cheaper option, the PS2MouseMini, a small cable adapter performing much the same job. Soon after, Castle produced a similar product. Both STD and Castle also produced their own Acorn-compatible mice.
In November 2003, Ian Nichols tells his readers, he discovered that some optical mice (those are the ones without wheels, but use LED reflections to determine motion) contain chips that are able to output quadrature signals as well as the PS/2 signalling. Screwdriver and soldering iron in hand, and using a cable from an Acorn mouse, Ian went onto to modify several mice for himself and fellow club members.
If you fancy having a go yourself, and saving a few pennies, then Ian has recently documented the whole thing, on his website.
Ian's original post
Optical mouse conversion plans
Previous: Light at end of Impression-X tunnel
Next: Web browser offerings compared
DiscussionViewing threaded comments | View comments unthreaded, listed by date | Skip to the end
Please login before posting a comment. Use the form on the right to do so or create a free account.
Search the archives
Today's featured article
Beginner's guide to manipulating stock photos
Getting your message across with ArtWorks and Photodesk
9 comments, latest by sascott on 8/8/06 9:16AM. Published: 6 Aug 2006
Using an A3010 as a central heating controller
Should have used an Intel processor to heat the water, snicker
17 comments, latest by MartinA on 21/10/05 4:02PM. Published: 17 Oct 2005
News and media:
RISCOS Ltd •
RISC OS Open •
MW Software •
Advantage Six •
CJE Micros •
Liquid Silicon •
Chris Why's Acorn/RISC OS collection •
The Register •
The Inquirer •
Apple Insider •
BBC News •
Sky News •
Google News •