VIC-20 "Pause" button

From: Jim Brain <>
Date: Fri, 12 Jul 2013 12:25:05 -0500
Message-ID: <>
I'm sure this is old news to most folks, but I was surprised.

Leif Bloomquist gave me an old VIC-20 Expansion Unit (6 slot) that 
contains a number of switches and knobs (it's really a cool unit, you 
can select which banks the 2 RAM slots use via knobs, the normal ON/OFF 
per slot, and some DIP switches for configs and a RESET button.).  One 
intriguing item on the PCB was a "PAUSE" switch. Dubious, I set the unit 
up, popped in a GORF, and started the game. Just as the name suggests, 
enabling the "PAUSE" button does indeed pause the game.

I checked, and the switch just grounds IRQ.  I suppose it makes sense, 
as the CPU would continuously go to the IRQ routine, never moving 
forward in the regular code, but it did surprise me.

I didn't exhaustively test, but I worked on non cart apps as well.

thought it odd that I've never seen a simple cartridge with a button 
marketed for the VIC-20 as a "pause your game" aid.  I would have 
thought such a product would have been marketed.


Jim Brain

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Received on 2013-07-12 18:00:04

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