kaufman@Shasta.STANFORD.EDU (Marc Kaufman) (12/01/87)
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? 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? 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 SuperMac's card, SuperMac's monitor, on SuperMac's stand. Is this artifact a product of the monitor, or the board. If it is the board, I don't want one. Thanks. Marc Kaufman (kaufman@Shasta.stanford.edu)
eacj@batcomputer.tn.cornell.edu (Julian Vrieslander) (12/01/87)
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 UUCP: {cmcl2,decvax,rochester,uw-beaver,ihnp4}!cornell!batcomputer!eacj ARPA: eacj@tcgould.tn.cornell.edu BITNET: eacj@CRNLTHRY
Fabian_Fabe_Ramirez@cup.portal.com (12/10/87)
Marc, Greeting, I'm with SuperMac Technical Support and here are some answers that I hope will satisfy your questions. 1. Well, both the packaging and literature state that the Spectrum video card will support multiple resolutions. This feature will be available in the next release of the firmware (as well as NTSC). For those that do _not_ have the Spectrum B11 ROM, please contact your dealer and make arrangements for an exchange with SuperMac. 2. The Horizontal Frequency is 48.190 KHz The Vertical Frequency is 59.28 Hz The Pixel Clock is 64.000 MHz 3. Any "verical artifact" is probably a result of Convergence which has not been properly adjusted. There is a convergence test that the "user" can use by selecting the Monitor cdev from the Control Panel and then using the V-Stat (Vertical Static Convergence Control), H-Stat (Horizontal Static Convergence Control), and the V-Cent (Vertical Centering Control). Once done, the convergence will be properly adjusted. If not, contact your dealer for proper adjustments. Also, any "Moiree" pattern can be eliminated by using Apple's new System 4.2 General cdev which allow you to change the color of your desktop pattern. I hope that this answers you questions. I'm suprised by your comment that SuperMac couldn't give you any answers. Could you send me E-Mail and let me know who you spoke to and when you called. I'd be more than happy to check this out. Fabian Ramirez fabian_fabe_ramirez@cup.portal.com SuperMac Technical Support sun!cup.portal.com!fabian_fabe_ramirez (415) 964-9660
thomas%spline.utah.edu.uucp@utah-gr.UUCP (Spencer W. Thomas) (01/21/88)
In article <2289@Shasta.STANFORD.EDU> kaufman@Shasta.stanford.edu (Marc Kaufman) writes: >I am looking for some information about the Spectrum video card ... >1. The box says that the board operates at 640x480 and 1024x768 I haven't figured out how to do this. The "manual" that comes with it has lots of pictures of video cables, but no indication of how to get a different resolution. (In fact, no programming info at all.) >2. What is the Horizontal Scan rate? I may want to use my own monitor. About 48 KHz. I haven't figured out how to change this, either (the manual is just as silent). Any 19" (1K resolution) monitor based on the Trinitron tube should work (we are using one from an HP "Bobcat"). >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 a moire pattern that results because the pixel size is slightly different than the phosphor line spacing on the Trinitron tube. If you select a different background pattern, it changes (or goes away). The background is not "a uniform gray", it has every other pixel on. This is about the worst background you can choose for showing up moire patterns. If you don't care about making the pixels on the Supermac screen spaced 72/inch, you can probably tweak the size controls on (inside) the monitor and make it either better or worse. Or you could really use a solid gray background pixmap... =Spencer ({ihnp4,decvax}!utah-cs!thomas, thomas@cs.utah.edu)