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From: eacj@batcomputer.tn.cornell.edu (Julian Vrieslander)
Newsgroups: comp.sys.mac
Subject: Re: Spectrum card from SuperMac
Message-ID: <3046@batcomputer.tn.cornell.edu>
Date: Tue, 1-Dec-87 15:20:11 EST
Article-I.D.: batcompu.3046
Posted: Tue Dec  1 15:20:11 1987
Date-Received: Fri, 4-Dec-87 21:30:27 EST
References: <2289@Shasta.STANFORD.EDU>
Reply-To: eacj@tcgould.tn.cornell.edu (Julian Vrieslander)
Organization: Cornell Theory Center, Cornell University, Ithaca NY
Lines: 49

In article <2289@Shasta.STANFORD.EDU> kaufman@Shasta.stanford.edu (Marc Kaufman) writes:
>I am looking for some information about the Spectrum video card for the
>Mac II.  Not surprisingly, SuperMac, the distributor, can not answer my
>questions.  Can one (or more) of you?:
>
>1. The box says that the board operates at 640x480 and 1024x768, changeable
>   in software.  None of the demo units I have seen has such a software
>   switch.  Is there one?

If there is such software, it did not come in with the Spectrum card that I
bought, nor is it mentioned in the doco (Spectrum User Manual, beta draft I).

>2. What is the Horizontal Scan rate?  I may want to use my own monitor.
>   The box says that several scan rates are provided.  Is this true?

Direct quote from the Spectrum manual: "If your non-SuperMac monitor has the
same timing specs as the Spectrum monitor, you can plug directly into the
video board."  No mention of several scan rates.  The spec sheet for the 19"
Sony monitor that SuperMac sells includes the following specs:

   Deflection frequency - horizontal: 63.34/48.8 kHz
                        - vertical: 59.98/60.0 Hz

>3. Every demo unit I have seen, using the SuperMac monitor, has an annoying
>   vertical artifact, consisting of purple lines, when a uniform gray
>   background is selected.  This is possibly due to EMI, but it is

I suspect that this is a Moire-like interference pattern between the dots
in the gray pattern and the spacing of the openings in the monitor's shadow
mask.  If you don't like it, try another desktop pattern.

Mild flame: although I have been quite happy with a number of SuperMac
products, and satisfied with their support, they have recently played a
bit loose with their advertising and promotion.  Maybe I am picking nits
here, but there have been a couple of advertised features that failed to
show up in the Spectrum card.  In addition to the above examples, my board
cannot handle 4-bit color, even though the lit says it can, and the promise
of a cheap GenLock upgrade has been reconsidered.  It will be an EXPENSIVE
upgrade, since the desgners found out there was more involved in the
implementation that they initially realized.  There is a free ROM upgrade on
the way which is alleged to cure the 4-bit color problem, and maybe some of the
other discrepancies between product and specs.  It sounds like the urge to
outspec the competition induced them to release the card before all the 
advertised features had been implemented and/or debugged.
-- 
Julian Vrieslander    (607) 255-3594
Neurobiology & Behavior, W250 Mudd Hall, Cornell University, Ithaca NY 14853    
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