** 3 page review / 2300 words ** ** Side banners: Falcon pro hardware: system accelerator ** CENTurbo II Blink and miss it. Shiuming Lai tests a new Falcon accelerator from French hardware specialist, CENTEK... ** CT2.JPG here ** Afterburner will go down in history as one of the most desired items on every Falcon owner's shopping list, and a milestone in Falcon acceleration itself. There are two main ways to accelerate a computer: feed a faster clock signal into the synchronous parts (overclocking, which has limited potential) or over-ride the original processor with something altogether more efficient and powerful, maybe with some extras like supplementary RAM attached. Afterburner belonged to the latter group, so when news broke that supplies had dried up, and no more would be built unless there was sufficient demand, the future looked bleak. Not any more. After a long development period, the successor to CENTurbo I has arrived. Welcome back to real Falcon acceleration CENTurbo II is a compact board (fitting snugly into a standard case as shown in our photograph) hosting a replacement 68030 CPU running at 50MHz, socket for a 68882 FPU at 50MHz, system patches, extra clocks for 25MHz system bus and 50MHz DSP, 72-pin SIMM socket for 32Mb fast RAM, and a flash ROM for easy firmware updates. This ROM contains a boot parameter configuration program, much like the BIOS chip found in PCs, only not quite as complicated. It doesn't tell you how many RPM your cooling fan is doing - I kid you not! From here it's possible to set the boot device polling order, IDE and DSP wait states, memory test, video mode, hard disk driver and select an operating system. The mysteriously-named Dolmen is not yet finished so we'll cover that when more details are available. The remaining choices are plain TOS 4.0x from the original ROM and TOS 7.04 - a patched version of 4.0x which makes fast RAM available to the system. To remind you which TOS you're booting, the patched one turns the screen colours to a striking, Swedish yellow-on-blue. If you hold down the [Control] key as the machine boots, the CENTEK AUTO manager kicks in, and rather than skipping all programs, it gives a choice to run or skip each program in turn - invaluable for trouble shooting. CENTEK's software disk includes a neat bunch of utilities for tweaking the system, and demo versions of its other software, like Sandrine, a scanner front-end. There are more affectionate names to come, like C‚cile, which, if from Germany, would efficiently be called HD Driver. The names are initially confusing, as is the small degree of functional duplication between some programs, but they serve to allow things to be done in several ways and are executed with unmistakable French flair and humour - check out the wicked poke at British beef! Extra marks for the effort of including programming resources, a sign of care and attention. Two of the most immediately useful programs are: CENTscreen, an AUTO folder patch to replace the Atari Set Video... dialog with a much better control panel, adding to the existing modes with new ones specified in a VIDEO.DAT file, screen saver, and virtual screen modes with three cleverly-conceived modes of scrolling. Edge, only scrolls when the cursor reaches the edge of the screen, Focus keeps the cursor in or near the centre while Proportional gives an idea of its virtual co-ordinates by scaling them to the physical - simple but brilliant. CENTVIDEL is a screen manager allowing custom resolutions to be defined and saved in the VIDEO.DAT file, ready for selection in CENTscreen. ** SETVIDEO.GIF ** ** Caption ** Good design soon becomes apparent ** /caption ** ** CENTVIDL.GIF ** ** Caption ** Take particular care with these utilities if the monitor doesn't have scan range threshold protection ** /caption ** ** NVRAM.GIF here ** Graphics Using standard Falcon VGA 256-colour GEM is like wading through treacle. CENTurbo II makes it a more productive mode, allowing programs like PixArt 4 to show their colours, literally, and still be responsive enough to work with comfortably. Alternatively, a higher resolution is sometimes more useful and CENTurbo II can do this, just like the old Blow Up/FX. 16-bit colour animations on Douglas Little's Falcon FLIC movie player race along with fluidity and vigour, in fact, some of the films on Team Computer's Neon Grafix demo CD made me feel a little dizzy after a few loops. Apex Media's Cyberdials come hurtling from the screen like missiles, and it also works nicely in 640x480x16-bit/pixel "TrueColor" thanks to the increased bus bandwidth and faster video clock. Smoother airbrush strokes and superior overall definition. Games Reservoir Gods' early God Boy releases such as Super Mario Land receive a healthy injection of zip, improving playability by a large margin, while the new improved God Boy X system is even better. Work hard, play hard! The only problem I came across was mangled music, hopefully it's a simple problem with an easy fix. 3D games powered by the DSP are in for a treat, give Running a go and see. Those using an elderly VGA display with their Falcon might be in for a shock. Notice how the image is shifted when low resolution programs, like many games, are run? This is caused by the different video timings, and if that wasn't a good enough reason to invest in a modern digital multiscan, CENTurbo II will change your mind. If the monitor can't handle it, you'll know. I easily managed to design a custom mode that shot past even the 120Hz limit of my fairly new Sony Trinitron. Acid test The music sector represents a major proportion of the Falcon user base, therefore an important assessment of an accelerator's value is its impact and stability with software in this area. Every Falcon motherboard is different enough in terms of timing characteristics to show signs of incoherence when pushed beyond its original specification. The audio sub-system is particularly susceptible to developing crackling and popping noises during replay if the system is overclocked. CENTEK was well aware of this "SDMA bug" and it took six months of brainstorming to resolve. Does it work? You can stop holding your breath now, I'm pleased to report it passed the Cubase Audio test. General compatibility is very good, and so it should be, using the same model of processor. Things which do fall down tend to be extensively hard-coded in weird and wonderful ways to leave no clock cycle spared. Any programs that crash are caught by the new exception handler, giving a choice to terminate the program or reboot. The fix is usually a trivial matter of changing the program header flags. Shareware programmers, make sure your registration delay routines are based on real time rather than coupled to the CPU instruction clock... Afterburner vs CENTurbo II: the inevitable question. I've got an Afterburner gathering dust somewhere, it's not fitted for several reasons: Don't get me wrong, Afterburner is still the king in a sense, but it did cost twice as much. The 68RC040 version's floating point performance knocks spots off the 68882 but for many purposes the CENTurbo II isn't far behind, and compares well bang-per-buck. On linear 32-bit memory access it actually surpasses Afterburner. Based on NemBench Falcon-relative figures, RWC (Read/Write/Copy) operations in ST RAM are at least twice as high as Afterburner and those in fast RAM still have a greater average. Benchmark figures should not be taken as the last word though, it all depends on dynamic conditions - how often these operations actually occur in running a program. Many complex factors are involved in choosing an accelerator. For example, the power of Afterburner should be matched to an equally capable replacement video system, that is, yet another, dedicated peripheral on the 68030 expansion bus. CENTurbo II is a tidy integrated solution, the luxury mini music system to the uncompromising hi-fi separates. At the other end of the scale, CENTurbo II offers more value for money than less expensive, purely overclocking-type accelerators such as Nemesis, Power Up 2 or indeed its own forerunner, CENTurbo I. It leap-frogs the barriers of that technique by starting out with components of a higher rating in the first place, then extends that with overclocking. Above all, it's solid as a rock and deserves serious consideration. Verdict: It's a spanner in the works for the Milan. Preliminary tests ** Table needed here ** System: 32Mb fast RAM, 16Mb ST RAM, NVDI 5, 640x480, 16 colours, Seagate Medalist Pro 4520 3.5" Ultra ATA hard disk (IDE bus) IDE and DSP wait states on. Note: DSP wait states made no difference in any of these operations or benchmark tests, but MPEG playing was clearly faster without. Timings in HH:MM:SS ** Mike, if you're up for converting this to a bar graph it would ** look a lot nicer ** Turbo off Turbo on ------------------------------------------------------ Zero-X v2 Test file: 16-bit stereo AIFF sample (6,750,752 bytes) Operation: DSP Detune (value 50, result to stereo) 00:01:02 00:00:25 Operation: DSP 8KHz HPF 00:02:14 00:01:04 Imagecopy 4 Test file: 1136x960 LZW-compressed 16-bit chunky TIFF Operation: Load and reduce to 4-bit planar 00:01:42 00:00:27 Operation: Convert to 75% quality JPEG 00:03:17 00:00:50 ** end table ** CENTurbo II versus Atari TT030 ** table here ** Using NemBench v2.1 (precision CPU/FPU profiler) OPERATION CENTurbo II TT030 Integer multiply 16-bitt) -> 1.921 Mips (~313%) 1.236 Mips (~201%) Integer divide 16-bitt) -> 1.135 Mips (~313%) 0.730 Mips (~201%) Linear (stalled) integer -> 24.975 Mips (~313%) 16.062 Mips (~201%) Interleaved (piped) integer -> 24.975 Mips (~313%) 16.062 Mips (~201%) 16-bit read (100% hit) -> 24.630 Mb/sec (~313%) 15.873 Mb/sec (~202%) 16-bit write (100% hit) -> 12.594 Mb/sec (~209%) 8.169 Mb/sec (~135%) 32-bit read (100% hit) -> 49.140 Mb/sec (~313%) 31.695 Mb/sec (~201%) 32-bit write (100% hit) -> 25.125 Mb/sec (~376%) 16.339 Mb/sec (~245%) Linear 32-bit read (ST-Ram) -> 10.208 Mb/sec (~192%) 7.858 Mb/sec (~147%) Linear 32-bit write (ST-Ram) -> 11.457 Mb/sec (~177%) 7.858 Mb/sec (~121%) Linear 32-bit copy (ST-Ram) -> 5.728 Mb/sec (~177%) 3.947 Mb/sec (~122%) Linear 32-bit read (FastRAM) -> 31.170 Mb/sec (~586%) 12.609 Mb/sec (~237%) Linear 32-bit write (FastRAM) -> 24.227 Mb/sec (~375%) 15.753 Mb/sec (~244%) Linear 32-bit copy (FastRAM) -> 10.152 Mb/sec (~314%) 7.872 Mb/sec (~243%) Using DSPBench v1.0 (precision DSP profiler) DSP ( X:Int Y:Int P:Int ) -> 25.000 Mips (~156%) DSP ( X:Ext Y:Ext P:Int ) -> 12.500 Mips (~156%) DSP ( X:Ext Y:Ext P:Ext ) -> 8.333 Mips (~156%) ** /table ** ** Caption (or part of table) ** 100% is a standard Falcon. CENTurbo II beats the TT on all counts, especially fast RAM access. It doesn't take any benchmark figures to work that one out though. ** /caption ** ** Boxout ** CENTurbo II technical Prototypes of the CENTurbo II were tested with a clock of 75MHz, using official 50MHz devices in ceramic PGA form (Pin Grid Array, a flat-pack with pins underneath). These are the premium selection from the good yield of a fabrication run, packaged in the more expensive chip carrier material favoured for high-performance designs due to its thermal properties (doesn't melt like plastic!). Unfortunately, getting hold of PGA 68030s proved difficult, and their price prohibitive - not only to purchase, but in terms of added complexity in the PCB routing, since pin-holes would have to be catered for. These final production units are much smaller, thanks in part to the use of surface-mounted FE33 chips, overclocked to 50MHz. During development, the CPU to fast RAM and Falcon motherboard interface was 25MHz, now it's always running at a full 50MHz, with wait states for slower hardware like the Falcon motherboard, rather than switching the CPU down to 25MHz for every access. This improved the transfer rate from 7.5Mb/s to 10Mb/s. The 68030 processor-direct expansion bus through connections on our Revision A board are to be dropped from the new Revision B units. CENTEK claims it will still be possible to connect CENTurbo II onto old expansion cards with some small adjustments. Standard Falcon FPUs rated at 16MHz need to be removed - CENTurbo II requires a chip with 33MHz minimum rating to work reliably at 50MHz. ** /boxout ** ** Boxout ** Fitting CENTEK's printed installation manual is quite clear and concise, although the claimed fitting time of 20 minutes is unrealistic. Even experienced electronics engineers should exercise caution, we think 2-3 hours is more appropriate. System Solutions should have produced a new, improved manual by the time you read this. There is a general misconception that being handy with a soldering iron is a qualification to accelerator installation involving PCB track cuts and SMT component modification. While there is little of that to be done with the CENTurbo II, be warned, computer motherboards are complex multi-layer affairs and replacements for the Falcon don't grow on trees. It takes electronics experience AND familiarity with the board layout and components. Our advice is, as always, if in doubt leave it to the experts. ** /boxout ** ** Product box ** Manufacturer CENTEK UK contact System Solutions, 17-19 Blackwater Street, Dulwich, London, SE22 8SD Tel: +44 (0)181 693 3355 Email: sales@system-solutions.co.uk http://www.system-solutions.co.uk/cafe/ Price œ199.00 introductory offer (normally œ229.00) Pros Stable and fast, slick supporting software, fits in standard Falcon case Cons 32Mb fastRAM limit, CPU cooling fan attachment isn't very sturdy 92% ** End product box ** ** Images and captions ** ** CT2_TOP.JPG ** 64Mb fast RAM support is under investigation for Revision B - the problem is price and availability of suitable EDO SIMMs. Having two sockets for twin 32Mb modules also prevents it from fitting in a standard Falcon case ** CT2_BACK.JPG ** Choice of SIMM is important, if they're too high the case won't close properly ** A_TRACK.GIF ** Here's Audio Tracker at 1024x768 - in 640x480 resolution the mixing desk fills the screen ** HRTC2.TIF ** Beautiful, vibrant, high resolution 16-bit colour displays, even with huge virtual screens and scrolling is always silky smooth ** F09.GIF ** Set the boot sequence to skip this if you've done one PC repair too many...