[Oberon] FPGA Oberon vs Ceres - mouse wraparound

Chris Burrows chris at cfbsoftware.com
Sun Jan 27 23:13:33 CET 2019

> -----Original Message-----
> From: Oberon [mailto:oberon-bounces at lists.inf.ethz.ch] On Behalf Of
> Skulski, Wojciech
> Sent: Monday, 28 January 2019 3:33 AM
> To: ETH Oberon and related systems
> Subject: Re: [Oberon] FPGA Oberon vs Ceres
> There are some little bugs as well. On our copy running on Pepino I
> noticed that the mouse cursor wraps around the screen. It disappears
> on the right and reappears on the left, or vice versa. Not sure if
> this was the case with Ceres.

My understanding is "that is not a bug, it is a feature". The behaviour is
documented in the 2005 edition of the Project Oberon book:

"SetMouseLimits permits to determine the limiting coordinate values of the
rectangle into which the mouse position is mapped and where the cursor is
drawn. The position "wraps around" in both the horizontal and vertical

P.S. I wish that every designer of on-display keyboards controlled by a TV
remote had considered this. E.g. it takes me 23 keypresses to spell out
'wojtek' without wraparound as opposed to 16 when wraparound is implemented.

Chris Burrows

CFB Software

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