Mac Scope Instruction Manual

vI) Macscope Inst­ruct­ion Macscope II Inst­ruct­ion Manual the Macscope II program is an audio soft­ware oscil- loscope for bot­h Mac and Windows which uses t­he comput­er’s sound input­ t­o acquire dat­a. the main features are Fourier analysis, signal averaging and working with triggered curves. M:2 MacScope Instruction Manual ISBN 0-9770828-0-6 Copyright © 2005 Moose Mountain Digital Press Etna, New Hampshire 03750 All rights reserved MacScope Instruction Manual M:3 Author’s Introduction There were two problems with the first Mac- In my third year of teaching physics at Dart- Scope. One was that our external hardware box mouth College, back in the 1960s, I was assigned sold for nearly $2000, and the equipment and to teach a large introductory course. The lab for interface became obsolete when the Mac went to that course had a collection of Heathkit oscillo- USB. scopes which I, as a theoretical physicist, found The main change that led to MacScope II impossible to operate. If you changed any scale, was the great improvement in the sound input the curve disappeared somewhere for a few sec- of computers. Eight bit sound input appeared in onds, then floated by a few times before settling the 1980s, but using that as an oscilloscope input down somewhere. I refused to teach the course gave very poor results. It is the 16 bit sound in- unless we scrounged up some Tektronix scopes put that gives us the excellent results we can get that were stable enough for even me to operate. with MacScope II. Shortly after that I got a grant to replace all the Using the computer’s sound input capabil- Heathkits with Hewlett Packard scopes which, ity eliminates the need for expensive external remarkably, are still running today. equipment. The cost of external equipment now When I first saw the Macintosh computer in ranges from $0 to $50. The disadvantage is that 1984, with its scroll bars for controls, I realized we are limited to the audio frequency range of 10 that the computer would make a great oscil- Hz to 2200 Hz. loscope. The advantage would be that the data The MacScope program is the collaborative would end up in the computer where it could be effort of myself and Chris Sweeney. Chris has immediately analyzed. No more digitizing of stayed up on the internal workings of Mac and Polaroid photographs of HP or Tektronix screens. Windows computers, and writes sample basic Within a couple of years we developed Mac- C++ code to handle…