Subject: REVIEW: Supra Turbo 28 Accelerator
From: [email-masked] (John A. Scott)
Date: 9 Sep 1993 13:53:32 GMT
Newsgroups: comp.sys.amiga.reviews

PRODUCT NAME

	Supra Turbo 28 Accelerator ("ST28")

	[MODERATOR'S NOTE:  This review was updated on September 20, 1993.
	Search for the text "[UPDATE:" to find updated information.
	-Dan]

BRIEF DESCRIPTION

	The Supra Turbo 28 accelerator (ST28) increases the speed of your
Amiga 500 or 2000 computer by using a 68HC000 processor clocked at 28 MHz
and high-speed static RAM cache.  (Paraphrased from the manual, page 4)

AUTHOR/COMPANY INFORMATION

	Name:		Supra Corporation
	Address:	P.O. Box 7101
			Albany, Oregon 97321-8000
			USA

	Telephone:	(800) 727-3443 (Orders, USA toll free)
			(503) 967-2410 (Orders)
			(503) 967-2440 (Tech Support 8 - 4:30 PST)
			(503) 967-2444 (SupraSupport BBS - 24 hours)

LIST PRICE

	$199.95 (US).
	I purchased this product for $145 + shipping.

SPECIAL HARDWARE AND SOFTWARE REQUIREMENTS

	HARDWARE

		Bridgeboard users should be advised that the ST28 will not
		work properly while using the Bridgeboard and must be
		disabled.

		Amiga 500 users should be aware that the original Commodore
		power supply may not be sufficient to power several expansion
		devices at once.  You might need a bigger one to use this
		product.
		
	SOFTWARE
		
		Tested under AmigaDOS 2.1.  According to the manual, it
		works under AmigaDOS 1.3 also.  AmigaDOS 3.0 compatibility
		is unknown because this version of the operating system
		is not available yet for the Amiga 500 and 2000.

		GVP Series II hard drive controllers will require the
		use of the GVP program "GVPScsiCtrl" if you are using
		Amiga DOS 1.3; 2.x users should not need it.		

COPY PROTECTION

	None.
	Supra utilities install on hard disk or floppy boot disk.

MACHINE USED FOR TESTING

	Amiga 500 (revision 6a motherboard)
	1 meg Chip RAM, 2 megs Fast RAM (via BaseBoard RAM expander)
	AmigaDOS 2.1:  Kickstart 37.175, Workbench 38.35
	DataFlyer500 SCSI controller with Quantum 52 meg hard drive
	BigFoot 200 watt power supply

INSTALLATION

	Hardware installation of the ST28 is easy.  It plugs into the
side expansion port.  On the A500 version, there is a pass-through bus
connector for attaching other peripherals that also use this slot.  On the
Amiga 2000, the ST28 card plugs into the 86-pin CPU expansion slot on the
motherboard, and the toggle switch mounts in one of the slots on the back of
the machine.  Normal installation of the ST28 will not violate the warranty
on your Amiga 500 or 2000 (if this is even an issue to anybody any more!).

	  Note:  according to the manual, the Supra Turbo 28 cannot be used
with Amiga 2000 machines that were manufactured in Germany in 1986.  These
Amigas use a 4-layer mother board that doesn't allow the ST28 to disable the
existing CPU signal.

	Software installation is performed via an installation program that
Supra provides.  This program copies several needed utilities and modifies
the startup script.  Installation can also be performed manually, but the
the procedure is not documented, so you should be careful if you must do
it this way.

	Note:  owners of GVP Series II hard drive controllers, as well as any
other controllers utilizing "hidden" DMA, will need to pay attention to the
special software installation instructions in chapter five of the manual.

REVIEW

	I'd always been pretty amazed at the speed of my Amiga -- that is,
until the Amiga 3000 and the various '030 and '040 accelerators came out.
All of a sudden, I had the low-speed blues, and unfortunately I had the
"I'm a poor student with no money" blues too!  Then early this year, I opened
a copy of AmigaWorld, and on the inside cover was a full-page advertisement
for a new Amiga 500 accelerator for $199.95!  I hadn't been this excited
about a new product since I bought my Amiga.  This ad promised 28MHz speed
(nearly the performance of an '030 accelerator with 32-bit RAM and
even faster than one with no 32-bit RAM) for less than half the cost of the
brand new '030 board I had been lusting after.

	It was many weeks after the AmigaWorld ad appeared before the ST28
actually became available.  (I'm almost tempted to believe that the ad was
really a market survey!)  I placed an advance order, and almost to my
amazement the product shipped instead of vaporizing!  The case for the
external Amiga 500 version is designed to match the A500's case very nicely.
It looks like the same case that Supra uses for the SupraRam expander.  It
adds about two inches to the Amiga 500's width.  Installation was simple:
unplug the hard drive, plug in the ST28, plug the hard drive into the ST28,
power up, let the software installer do it's thing, and that's it!  My
machine was up and running in less than 15 minutes.

	Operating the ST28 is a breeze.  The acceleration can be toggled on
and off using either the hardware switch on the back of the unit (or the
Amiga 2000's case for the A2000 model) or using a software command.  In the
latter case, either Workbench icons or CLI commands can be used.  Supra
suggests that you check the software buttons (icons) to be sure if you are
accelerated, since the buttons have priority over the hardware switch.  This
means that it is possible for the hardware switch to be in the off position
and actually be accelerated via software, or alternately have the switch in
the "on" position and turn the acceleration off via software.  The software
buttons always reflect the actual state of the ST28's acceleration, so they
are always reliable indicators.

	I have found that my machine will not boot with the hardware switch
in the "on" position.  I normally leave it off, except when playing
floppy-based games, allowing the software to turn the acceleration on at
startup.

	After using this unit for many hours, I'm happy to report that it
performs virtually as advertised, and I've had no difficulties with mine.  I
say "virtually", since advertising 28MHz speed is somewhat misleading.  Keep
in mind that the Amiga tries to take the load off of the CPU by assigning
work to the custom chip set.  Therefore, while a 28Mhz CPU is four times as
fast as the stock 7Mhz 68000 used in the Amiga, the actual speed increase is
less than four-fold.  According to the manual, it is actually the static RAM
cache that provides most of the increase in performance.

	So what should you expect from the ST28?  Compared to a stock Amiga,
some applications fly with the ST28, especially those that involve data
compression like LhArc and my hard disk backup program.  GIF and JPEG viewers
speed up too, but not as much.  PageStream and Final Copy II print to my
Deskjet 500 at more than twice their original speed.  This accelerator
has worked with every game that I have tried it on, and it improves the
responsiveness of the flight simulators very nicely.  Overall, I'd estimate
a two or three fold speed increase depending on the application.  Certainly
this is not earth-shaking, but it sure beats nothing.

	[UPDATE:  Users of the Supra Turbo 28 can expect an increase in
	disk performance on the order of 80-100 kilobytes per second.]

	If you can afford an '030, you may want to pass on the ST28.  Then
again, for the price of the '030 board you can probably afford to buy an
Amiga 1200, which in the long-run is arguably the best overall "expansion."
But, for poverty stricken folks like me who need to squeeze some more time
from their old standby Amiga 500 or 2000, the Supra Turbo 28 is worth
looking into.

DOCUMENTATION

	Supra provides a 19-page manual.  This manual briefly covers the
following topics:  installation of hardware and software for both Amiga 500
and 2000 models, using the included software, and trouble-shooting.  This
information is clear, concise, and should be adequate for most circumstances.
I would have liked to have seen a more in-depth description of the software,
since if problems arise it would be difficult to troubleshoot.

LIKES AND DISLIKES

	LIKES:  Price, Price, Price.  The ST28 is less than half the cost of
the average '030 accelerator.  Furthermore, while the '030 accelerators (when
accompanied with 32-bit RAM) offer greater speed, they can be incompatible
with software that was written especially for the 68000.  The Supra Turbo 28
uses a 68000, so compatibility is nearly perfect.  Another plus is that this
unit is very easy to install (without voiding any Commodore warranty) and
use.  It toggles on the fly.  The pass-through port is vital in my opinion,
since I'd never sacrifice my hard drive in exchange for CPU speed.  Finally,
the ability to toggle acceleration on and off using either the hardware
switch or software while running is great.

	DISLIKES:  Not many! I think more complete documentation would be
desirable, but the manual is adequate for normal installation and use.  I'm
not crazy about having another device stacked onto the side expansion port
(of course this is due to the expansion limits of the Amiga 500).  Perhaps
an internal version similar to ADSPeed could be developed?  Also, the ST28
gets pretty warm, although there are air vents.  Finally, not being able to
use a Bridgeboard while using the ST28 is also a dislike.

COMPARISON TO OTHER SIMILAR PRODUCTS

	I do not own any other accelerators.  (Anybody care to donate? :-))

BUGS

	According to the manual, I should be able to boot up with the hardware
switch toggled to the "on" position. I have found that it will not. This is a
minor problem since the software switches the accelerator "on" as part of the
machine's startup.  Alternately, it can be turned on via the hardware
switch after the machine has booted.

VENDOR SUPPORT

	I have never attempted to contact Supra.

	I have no connection with Supra other than owning two of their fine
products (ST28 and SupraModem) with no difficulties.

WARRANTY

	The Supra Turbo 28 has a one year limited warranty.

CONCLUSIONS

	The Supra Turbo 28 is an excellent value in acceleration for the
Amiga.  It offers a noticeable speed increase at a small price.  Spending
twice the money will probably not get you twice the speed increase that this
unit offers.

COPYRIGHT NOTICE

	Copyright 1993 John A. Scott.  All rights reserved.

	Reprint permission is granted to all Amiga User Group Newsletter
Editors for use in user group newsletters.

	[MODERATOR'S NOTE:  Consult the monthly "Introduction to
comp.sys.amiga.reviews" article for full reprint information for any
review.  - Dan]

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