Afterburner 040

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Let me start this piece by stating a few facts.

A Quick History Lesson

For those of you who read my article previously published by the FFF, on fitting my Falcon into a System Solutions Lighthouse Tower, you will remember that I have been waiting to get my hands on an Afterburner since July 1995. At that time Gastiener were the UK distributer, because the Afterburner was sold by GE-Soft. Since then it has swapped to Overscan, giving Compo UK the rights. Compo went under so Titan Designs grabbed the distribution earlier this year.

I wanted to get a 68RC040 powered board because it has a built in FPU. The LC040 does not have the FPU. Sadly the RC version was becoming impossible to get hold of but the overall performance increase and extra RAM would be more than a touch useful and only my 3D model rendering with Xenomorf would suffer. Assuming of couse that the 040 would be slower than the 030+FPU combination, so I settled for an LC040 board.

Todays Second Lesson: Computer Architecture

I am no expert at this so I apologise in advance for any errors. This is the my understandng of how it works.

The Falcon’s normal bus runs at 16MHz and is shared by the 030, the RAM, the DSP, the FPU, and the sound and video hardware. This compromises the overall performance of the Falcon.

Let us look at screen updates of around 60 times a second on a 640x480, 16 colour VGA display. This means that about 150K is sent through the bus 60 times every second. That totals around 9Mb a second. So even when the machine is doing nothing it is shifting 9Mb of data around every second. The bus is capable of a transfer rate of 64Mb per second. Therefore 14% of the machines time is spent just updating the screen. This is why the machine speed alters with resolution. A 256 colour display takes twice the memory of an equivalent 16 colour display, and therefore requires twice the bus time. This is why something like the TurboBlanker screen saver speeds up the machine. The screen updates are stopped, freeing up the bus.

The Afterburner has it’s own bus and it’s independent from the Falcon’s, it is effectively a separate computer. This is assuming that there is FastRAM installed, without it the Afterburner has to constantly access the ST-RAM nullifying most of the performance gains. Making it more like installing the PowerUp2 32MHz upgrade. Software run solely on the Afterburner will not be affected by the constant screen update. Though of course the software still has to send data of any changes made to the screen to the ST-RAM.

Most new software will automatically use the FastRAM. Older programs can often be forced into using the FastRAM by using a utility supplied with the Afterburner or one of the others currently available. Be warned not all software works when you do this. Again it is mainly games and other software that accesses the hardware directly that tends to cause problems.

The Sorry Tale

The Afterburner arrived in a very big box. I began to wonder if my tower case was going to have enough space to house the board. Buried in the foam chips was an anti-static bag containing the Afterburner and a smaller board with two 16Mb SIMMs, a ribbon cable, a disk, and the instructions.

The instructions were in German. Entirely.

My German is limited to say the least, though when it comes to technical things many words are the same in any language. I could make out the basics and with help of a translation program on the Falcon and a large English-German dictionary I managed to work out most of what was said. Just enough to be worried.

Dimensions

The board is 6.5" (16.5cm) long and 5" (13cm) wide. From the top of the fan to the bottom of the expansion slot socket it is about 1.5" (4cm) deep. When plugged into the Falcon’s expansion slot it pretty much fills the gap from the power supply to the front of the motherboard and from the left hand edge of the PSU to the left hand edge of the IDE drive. Through ports are provided so that anything that is normaly in the expansion slot, Expose for example, can be fitted on top of the Afterburner. Through the closeness and height of the 040 and it’s fan you may need spacers to lift any extras above it.

Fitting

The most obvious thing that needed attaching was a ribbon cable with a plug on one end. This plugs onto the Afterburner with 8 free wires on the other end that need soldering to various chips on the motherboard. The chips are the four at the front of the motherboard, called the GALs, I think.

If only that was it, it would be a very simple upgrade to perform. Just solder these 8 wires to 8 pins on various chips. Plug the Afterburner into the expansion slot and plug the ribbon cable into the Afterburner. Wire the fan into a suitable voltage line. Doddle.

Even the separating of a couple of pins on the 030 from the motherboard is easy enough... Did I not mention that bit? Oops. This is simple to do but it is one of the most worrying things I have ever done. Having ’broken’ the pins there is no going back. The machine isn’t useless, not quite, more of which later.

Sadly it is not that simple. At least for most of us.

Clock Patch

The big stumbling block was the requirement of a ’clock patch’ which had to be fitted. This is needed due to those helpful people at Atari cutting corners and giving us owners problems. From what I have been told parts of the Falcon board are almost useless. Junctions and resistors are in places that really don’t need them and, but for the addition of a simple component, a set of signals supplied are rather weak. Basically a 16MHz signal is generated for the system to use. This signal is split into three for various parts of the board. Resistors are used to prevent bouncing signals merging together and giving an unreliable signal. This all combines to give a signal that most of the time is OK but if you are doing direct-to-disk recording and/or using fast SCSI devices or fitting an acceleraator board the weakness of the signal can cause corruption. The clock patch boosts this signal. All C-Lab Falcons have this fitted and many of you will have one installed already. You lucky people.

There are several variations of the clock patch all achieving the same goal. There are diagrams of two different methods in the manual, the German descriptions for which were almost imponderable. Did it matter which one I used? Did it depend on the revision version of my Falcon? Hhheeelllppp!

David Encill at Titan Designs put me in touch with someone who knew what they were doing and he pointed me in the right direction. I got my Falcon going without the patch and he E-mailled me a couple of diagrams and some instructions, all in English. An additional chip needs to be purchased, the 74F04, it is a hex-inverter. Pins on this need to be connected with various points on the board, most of which are on one particular chip. It took me several goes to get it running but eventually it did.

With the various wires and the chip I’d soldered I was a little concerned that a bare wire may come into contact with the bottom of the Afterburner. If you piggy-back the 74F04 onto the relevant chip the Afterburner will almost be resting on it if plugged in firmly. To prevent any short circuits I sellotaped a piece of thin cardboard to the bottom of the Afterburner.

Without the clock-patch I found the Falcon was very unstable, which is to be expected. Crashes could happen at any time and even booting up became a problem. Using a 2 colour resolution enabled me to get a reasonable level of stability. While trying to buy some 74F04s it spent nearly a week without the clock patch. It was used very little during this time but with no problems. My main worry was file corruption and consequent possible hard drive data damage.

The actual soldering was not too much of a problem. I am a real novice when it comes to doing such things and perhaps, in hindsight, it was a little foolish to attempt it. Taking a soldering iron to your thousand pound computer, the one you’ve been using nearly every day for two years really makes you think.

You would think that soldering and desoldering various wires several times would damage the motherboard irreparably, but these things are amazingly resilient.

I fitted the Falcon into the tower case successfully, not that it compares in complexity to fitting an Afterburner, and I was determined to do this. With the design of the tower I could hinge open the machine and do all the work without having to remove the motherboard. Though many would prefer to do so.

Software Patches

The next big problem arrived when I installed the software patches. To make the 040 and FastRAM work, software patches must be used. One does something to the MMU and makes the machine run from the 040. If the Falcon is booted without the patches, i.e. holding down control, then it thinks it has an 8MHz 68020 chip, according to the cookie jar, and acts accordingly. Without the Afterburner plugged in it won’t boot at all. The others patches are for the FastRAM and an FPU ’emulator’. The FastRAM and FPU patches caused me a few problems. The FastRAM patch has a dislike to being autobooted, the FPU patch would just bomb.

The patches should be auto booted and run first. Executing them from the desktop is possible but the system may get confused so it is best avoided.

The manual suggested that the FPU patch was a software 68882 emulator which would allow my FPU aware software to run even if it wouldn’t be as quick as an RC040. Any Falcon FPU already fitted is ignored when the Afterburner is installed. I’m told that the FPU patch is actually for making the RC040’s FPU more 68882 compatible, not a software emulator. Apparently a software FPU emulator exists but has yet to be tracked down.

According to people in the know there are two different verions of the patch programs and two different versions of the board. Each board type has corresponding patch software. So you might not even get the right set of patches. Wonderful!!

In the middle of all this I received a patch written by Doug Little, he of Apex fame. This replaces the MMU and FastRAM patches and is a huge improvement.

Now we come to the FastRAM saga.

Initial use of the supplied patches gave the expected 32Mb of FastRAM but my software really didn’t like running in it. Doug’s patch reduced the available RAM to only 11Mb. Swapping the two SIMMs over gave zero RAM. For this reason I assumed that one of the SIMMs didn’t work at all and that the other was a little faulty. It seemed a reasonable assumption. I know you have to be very careful about static electricity especially with SIMMs. I was as careful as possible. With only the partly working SIMM plugged in, the original patches still caused the machine to think it had 32Mb installed. Work that one out. Even with the reduced 11Mb of Mr Little’s patch some software didn’t work at all or would crash after some use.

An updated version of Doug’s patch reduced the RAM to only 8Mb but I didn’t have the software problems of earlier. I wanted to get the SIMMs tested on another computer but this didn’t come about as soon as I’d hoped. So I tried the SIMMs again in a last ditch attempt. If they didn’t work this time they were being sent back. This time I also decided to have a fiddle with some ’jumpers’. They are on the Afterburner next to the SIMM slots. No one seemed to know what the jumpers were for, so I thought I would try and find out.

There are two jumpers each made up of three pins and a cap to short either pins 1 and 2 or 2 and 3 together. The non-working SIMM on the first go showed the 8Mb that the partial working SIMM gave. Swapping the jumpers around enabled the proper 16Mb. Putting the 2nd SIMM in and further jumper fiddling gave me the full 32Mb.

With various combinations of SIMM and jumper I could get 0, 4, 8, 12, 16 or 32Mb of FastRAM.

I just couldn’t believe it. A SIMM that just a couple of weeks previously gave no RAM at all suddenly gave the right amount. I had even had doubts about the functionality of the SIMMs sockets themselves and I didn’t fancy sending the whole lot back.

I still can’t figure out if I missed something last time. Oh well it all looked like it was working.

The next test was the software that previously took a distinct dislike to FastRAM. Would it run?

Would filling the RAM show up damage in the SIMMs?

I spent a fun few minutes running MultiTOS, not a thing I often use, gradually and gratuitously filling the memory.

I got to within about 2Mb of filling the FastRAM before stopping. The standard built in 4Mb of ST-RAM was hardly touched.

The software that didn’t previously like the FastRAM’s mere presence now worked. And I had no problems with corruption.

Six weeks after getting the Afterburner I had the Falcon I wanted. After a brief return to instability caused by one of my soldered wires coming lose the Falcon has been very stable. It usually spends at least a couple of hours a day switched on, it has even done a few all night rendering sessions, without problems.

Software Compatibility

Half the fun of any upgrade like this is finding out how much of your software collection actually works. The answer is most of it. The real problems will be with Falcon specific stuff such as games. A few will work but not many.

The vast majority of normal software works. Thanks to the advent of MultiTOS and the fact that most new Atari software is written to work on all machines. These types should all work with the Afterburner.

By preventing the Afterburner initialising and reverting to the 8MHz 68020 mode some software that took a dislike to the 040 or FastRAM worked.

Here is a short list of software and comments:

Performance Figures

Okay, okay. Your thinking.

This is all very well but how fast is it?

The most obvious thing is that the desktop is just plain quicker, using something like WinX to give realtime scrolling and dragging, it is noticably smoother. Using a higher resolution has less of a performance hit than previously, for the reasons stated above.

Using CAB/STiK online the actual downloading isn’t any quicker but the formating of text and tables and converting the graphics is much quicker so more can be achieved in the same amount time.

I haven’t used it much but MultiTOS will be more usable with more RAM and processing power.

Yes, yes, but we want actual figures!

Okay. For things that make use of the DSP, such as JPEG viewers the speed increase isn’t really noticable. For real CPU intensive tasks it is around 6 times faster.

For example I have several MPEG viewers. One that uses the DSP gains an increase of less than 1 frame a second with Afterburner+FastRAM, on top of the usual 13fps. Another player that only uses the CPU and consequently normally runs at more than 1 fps in the 030 jumps to 7fps when run in the 040 and FastRAM. Without the FastRAM it got to around 2fps.

I would like to show some amazing figures for rendering but because my Afterburner doesn’t have an FPU and the Falcon’s is ignored, rendering is actually slower. But because of the extra RAM I can render much more complex models than would have been possible with virtual memory before. So in that respect rendering complex models will be quicker because the virtual memory will slow the system to a crawl. Trust me I know about exceptionally long rendering times using virtual memory. As mentioned earlier Outside does not work with the Afterburner. It must be looking for the 030 cookie jar entry and can’t find it.

More figures! Give us more figures!
Okay, okay. Some tables for you. ’TT’ in the tables below refers to TT-RAM, the Atari name for FastRAM.

#
STZip
1.1Mb of text files
030040+TT
Unzipping44s25s
Zipping2m10s29s

Wow! Zipping up almost as fast as Unzipping!

GEMView 3.16
Loading images with 256 colour display
030030+DSP040040+DSP040+TT040+DSP+TT
GIF (640x400)15.4s-6.5-4.5-
JPEG (533x368)1m44s1m23s45s37s21s17s

This shows the extra speed of having the FastRAM installed and the merits of the DSP. The DSP can decode the JPEG faster than the 040 but the 040/FastRAM combination can easily out do the 030 when it comes to the dithering to 256 colours.

GEM Bench v4.03
Falcon 030 TOS 4.04
AES v3.40, GEMDOS v0.48
MiNT not present
Blitter not present, NVDI 2.50 present
Video Mode: 640*480*16
FPU not present, Run and Malloc from FastRAM
Ref: F030, 640*480*16
The same setup but
without the
Afterburner fitted
GEM Dialog Box:1.440320%1.155400%
VDI Text:0.4251129%0.730657%
VDI Text Effects:1.130907%1.760582%
VDI Small Text:0.3351373%1.260365%
VDI Graphics:2.480463%4.565251%
GEM Window:1.325166%1.400157%
Integer Division:0.940330%3.110100%
Float Math:0.000----0.370100%
RAM Access:0.2251133%2.58098%
ROM Access:0.225955%2.57583%
Blitting:3.595102%3.480105%
VDI Scroll:4.945137%4.475151%
Justified Text:2.625205%3.685146%
VDI Enquire:0.1651060%0.825212%
New Dialogs:1.395419%2.480235%
Graphics:571%296%
CPU:806%95%
Average:621%242%

The FPU figure is not included in the Afterburner test because it crashes if the test is attempted. The Afterburner CPU figure would be higher still if the FPU could be included.

In summary.

With better instructions, and this wonderful write up, fitting should not be too difficult, if a little nerve racking. Hopefully by the time you read this an English manual will be ready. If not, ask Titan Designs for all the instructions and patches that were given to me. They will make life much easier.

As tricky and agonising as fitting became at times getting it working certainly gave me a huge sense of achievement. The reason that my Falcon is so much quicker and has more memory is because I fitted it. Every time I switch it on the reason it even boots up is because I fixed it. And if it starts to go wrong, as it has done once, I have more chance of fixing it myself, or at least understanding what is wrong.

Ultimately the Afterburner has not yielded quite the level of performance gain I had hoped for, primarily due to the lack of FPU to compare rendering speeds. The general speeding up of everything is nice though and the extra memory is fantastic. No more out of memory messages. For normal use 32Mb is more than enough, perhaps even a little excessive, 8 or 16 would be just as effective, but with the recent drops in the cost of memory why not?

To summarise the summary.

If I can do it then so can you and it was definitely worth it.

Contact:Titan Designs on 0121-693 6669
E-Mail:100345.2350@CompuServe.COM
Price:LC £449 -:- RC £539



Richard Elwell



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