SuperMac Spectrum/24 Series IV

The SuperMac Spectrum/24 Series IV card is a 12" NuBus card compatible with 680x0- and PowerPC-based Macs running up to Mac OS 9.0.4 as long as the PPC-compatible ROM (v. 3.0 or later) is installed. (In other word, if it works with a Power Mac, it will work all the way to Mac OS 9.0.4.)

Hands On: Chris Lawson

Feels about the same as a Thunder/24 as far as overall speed. I benchmarked a Series IV with a Series V ROM v3 in it for kicks, since I had the ROM around. Tested in a Mac IIcx running System 7.1.0. Here are the numbers:

computer            1-bit   4-bit   8-bit
IIcx, "Toby"        0.252           0.248
IIcx, 8•24GC        0.421           0.422
IIcx, accelerated   0.290   0.273   0.419
IIcx, unaccelerated 0.290   0.272   0.257

The "Toby" card is Apple's unaccelerated Macintosh II Video Card. The Spectrum/24 Series IV accelerated performance 15-70% in these tests. Although only slightly accelerated below the 8-bit setting, in the 8-bit mode it holds its own against Apple's 8•24GC video card when used with V5 ROMs.

Interestingly enough, most of the ROMs on the SuperMac Spectrum and Thunder cards seem to be completely interchangeable as far as basic function goes. I haven't tried using a Thunder with a Spec24/IV ROM in it with the GX accelerator, but basic QuickDraw functionality (not speed) seems to be unaffected by swapping the ROMs willy-nilly.

Now, I decided to see if the ROM made much speed difference, so I put the original Spec 24/IV ROM v1.6 back in the card.

computer            1-bit   4-bit   8-bit
IIcx, ROM v1.6      0.297   0.275   0.377

I had a bit of a problem - I couldn't turn acceleration off. Removing the software didn't do a thing for it. I'll just say, "It's probably slower if you can turn acceleration off."

The Spec 24/V v3.0 ROM was about 10 percent faster in 8-bit mode and essentially equivalent otherwise. Worth noting: the SuperPower 3.1 extension works with the Spec 24/V ROM but not with the original ROM in the card. This is why I couldn't turn acceleration off.

With the Spectrum 24/Series IV ROM v3.0.0 installed, the SuperPower extension does work and allows acceleration to be turned on and off.

The only number that was affected at all was the 8-bit acceleration, which increased to 0.421. 16-bit is still not supported. 1-bit through 4-bit remained virtually identical to the numbers generated with the v1.6 ROM.

computer            1-bit   4-bit   8-bit
IIcx, accelerated   0.297   0.275   0.421
IIcx, unaccelerated 0.291   0.273   0.259

Again, the only numbers that changed significantly were for 8-bit mode. It looks like the SuperMac drivers don't accelerate anything below 8-bit at all. If you have a real need for accelerated bit depths below 8 bits, get an Apple 8•24GC. If you need more than 8-bit colour, and you need it accelerated, this is a pretty good (and cheap) card for that.

Acceleration/Resolution/Color Support

The card provides standard QuickDraw acceleration and supports the following resolution/color combinations:

• 512 x 384 up to 24-bit
• 640 x 480 up to 24-bit
• 640 x 870 up to 24-bit
• 832 x 624 up to 24-bit
• 1024 x 768 (at 60 or 75 Hz) up to 24-bit

Software

Links to Radius and SuperMac software on Gamba's site.