PrecisionColor/UniversalColor/LeMans Cards Q&A,


Q: Are there any compatibility concerns related to running System 7.5 or using the card in a NuBus Power Macintosh?

A: Yes. For System 7.5 and Power Macintosh compatibility, we recommend Dynamic Desktop version 3.3 or later, QuickColor 3.3 or later, and ROM 2.0 or later. In addition, the Power Macintosh 6100, due to its limited expansion slot will only accept a 7-inch, or smaller, version of these graphics cards. Ensure that your card is at most 7-inches in length before installing into these, or similar, machines. The 6100 also requires Apple's NuBus Adapter card available from Apple resellers. (!)

Q: Are there any compatibility concerns related to using these cards in the PowerMacintosh 9500, 8500, 7500, 7200, or other PCI-bus models?

A: These cards are for NuBus Macintosh CPUs ONLY. These cards are not compatible with the PCI-bus architecture. No adapters can be used to make these cards compatible with the PCI slot, and although some manufacturers do make a NuBus expansion chassis which will interface with a PCI slot, Radius cannot recommend or support its use.

Q: What resolutions are supported?

A: PrecisionColor & UniversalColor cards support the 640x480 Apple timing, 800x600 VGA timing, and 832x624 - Apple's 16-inch timing. The XK version of these cards adds additional support for 1024x768 at either 60Hz or 75Hz vertical refresh, and the PrecisionColor 24X series, as well as the LeMans, include suspport for 1152x870 and 1152x882 for large screen color and monochrome displays. The PrecisionColor 8XJ will support all of these resolutions, but is limited to 8-bit, or 256 colors or grays, rather than the millions of colors generated by the 24XP, XK, X, and LeMans GT series of cards.

Q: I ran Speedometer and Norton Utilities' System Info, and they say that my card isn't as fast as my Mac's built in video. Is something wrong?

A: The measures for built-in-video are often based upon 8-bit graphic performance and often at only 640x480, or 14" resolution. On the other hand, the Radius cards are being measured for 24-bit graphic performance. The difference in the number of calculations, and hence time, a CPU must make between 8-bit color depth and 24 -bit color depth is astronomical. Therefore, this is an unfair comparison. What you are experiencing is indeed 24-bit accelerated graphics, which may or may not be faster than 8-bit built-in-video, depending on the card and CPU in question, but it certainly produces a significantly better picture. If photo realism and graphic beauty are not important to your work, you may wish to drop down to the 8-bit level of 256 colors for potentially increased speed. The true value of any graphics card is its ability to generate and accelerate 24-bit images.

Q: I purchased my graphics card in order to accelerate Adobe PhotoShop, and am not seeing any speed increase. Why not?

A: These cards will not accelerate any of the PhotoShop plug-in filters, since the cards were designed to accelerate Apple's QuickDraw routines. However, you should see an increase in QuickDraw functions used within Photoshop - such as screen redraw, and scrolling. PhotoShop is a very memory-intensive application, and enough dynamic RAM hasn't been allocated to the application for a document to reside totally within RAM, PhotoShop will search for "scratch disk" to use. This is similar to using "virtual memory," and is inherently slower than using dynamic RAM. A good rule of thumb is to give Adobe PhotoShop four times more memory than the document you are working on. Therefore, if you are working within a PhotoShop document which is 10 megabytes in size, you should assign 40 megabytes to the PhotoShop application.

To assign additional memory to any Macintosh application:

Q: I have a 3-slot NuBus Macintosh. Can my power supply handle one of these cards?

A: Probably, but it's really dependent on the state of your power supply and the other cards in the NuBus. The allowed power per NuBus slot is 13.9 watts. If you have other NuBus cards which are using more power than this, then you can't populate all of your NuBus slots. All of the PrecisionColor, UniversalColor and LeMansGT cards are within, or fall below, Apple's power specifications.

Q: My PrecisionColor card is generating purple bars on the screen of my 19-inch display. Why?

A: Your 19-inch display is either a Radius Color Display 19 (model 0031), also known as the GDM-1950, as it is designated on the back, or another display which operates at a fixed resolution. If so, these unwanted purple lines are the result of the display and cable not syncing properly due to the collision of old and new technology. This can also occur with other displays. You can relieve this problem, by dialing 800-977-7060 and ordering part number 590-0040 or 590-0058-02. Either of these cables will allow the card to properly sense the RCD19 display.

Q: Will I get 24-bit video on my Pivot display using one of these cards?

A: Yes, but only the Precision Color 24xk, and 24x will operate in the display's native orientation - landscape mode for the PrecisionColor Pivot Display (model #0356), and portrait mode for the fixed frequency Color Pivot Display (model #0277). The Precision Color 24xp will not work with the 0277 Color Pivot. The PrecisionColor cards do not include the circuitry which allows pivoting. As a result, you can get 24-bit video on either of the displays, but only in one screen orientation. Either of these displays is capable of better-than-8-bit-depth in either portrait or landscape, with pivoting enabled, if used with the built-in video of a compatible Centris, Quadra, or Power Macintosh computer. AV versions of the Centris or Quadra will not allow pivoting. The AV versions of the Power Macintosh will allow pivoting from the DRAM video port, but in 8-bit only. Radius does not make a 24-bit card which will allow pivoting.

Q: What differentiates the LeMansGT from a PrecisionColor Pro 24X?

A: The LeMansGT uses a 10-bit digital to analog converter, rather than previous 8-bit technology. Since the additional 2-bits of resolution help to smooth out the gamma curve, this allows the LeMansGT to more accurately display colors. The LeMans is also faster than the PrecisionColor Pro 24X.

Q: Do the PrecisionColor, UniversalColor, and LeMans GT cards offer hardware pan and zoom?

A: No, these cards do not support hardware pan and zoom capability. However, most of our Spectrum and Thunder series cards do.

Q: Do these cards offer "on-the-fly" resolution switching?

A: Yes, provided you are using a multi-sync display and have installed a version of RadiusWare or Dynamic Desktop software which is compatible with your system. All you need to do is install the software and restart. Then, open the RadiusWare or Dynamic Desktop Control Panel Device, depending on which you've installed, enable it, and restart the computer. After the computer has fully restarted, simultaneously hold down the "command," and "option" keys, while clicking the mouse. A pop-up menu should appear which offers you choices of available bit-depths and screen sizes. If this does not happen, check to make sure that the software is enabled. If, after opening the control panel, a dialogue box appears which states, "RadiusWare or Dynamic Desktop cannot be used with this Macintosh," you need to order a more current version of the software. To do this, call Radius Upgrades at 800-977-7060, and order part number 630-0333.

Q: What's the difference between the PrecisionColor Pro series of cards and the original PrecisionColor cards?

A: The Pro line has been scaled down to 6.5" to fit in the smaller NuBus slots of the newer Macintosh computers, and has been designed with a different ROM-type and different chips. The re-design combined with the revision to the QuickColor drivers for the card have given it a higher top speed. This increase is for QuickDraw only and does not take separate Photoshop filter acceleration into account. If you are interested in Photoshop filter and plug-in acceleration, you may wish to look into a dedicated Photoshop accelerator, such as a Radius PhotoEngine. The Photoengine is equipped with four digital signal processors and offers the greatest Photoshop speeds currently available on a Macintosh.

Q: My display is capable of 1280x1024 resolution and higher. Will these cards support my monitor?

A: These cards will drive these 20 and 21-inch Macintosh compatible displays, but not at resolutions higher than 1152x882. As of today, the largest resolution supported by any of these cards is 1152x882. However, the new Radius Thunder IV series and Thunder/24 GT cards all support up to 1600x1200 resolution.


Return to Radius Technical Q&A

Comments to support@radius.com