UD182050@NDSUVM1.BITNET (Mike Aos) (10/01/90)
Maybe this has already been here, but I found it on a friends HD when I was
trying to get mine working, and I thought it might be of interest to others.
The following may be obtained by sending a self-addressed stamped envelope to:
Western Design Center, Inc.
2166 East Brown Road
Mesa, Arizona 85203
602-962-4545
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I re-keyed the following from the original mailing sent by Western Design Center. A word or phrase enclosed by "*" was boldface in
original. Special emphasis indicated by text in all capital letters.
If you order from WDC, you would do well to request this information direct from them. They may have updated the recommendations
since the original mailing.
-- Charlie Stillman, TechAlliance (too chicken to attempt the upgrade).
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Upgrading a Transwarp.GS Board
Prepared for the Western Design Center, Inc. by Andrew Hall
12 March 1990
(DISCLAIMER: the following document contains suggestions from various people who have upgraded Transwarp.GS boards. The author
himself has not tried these! Follow these suggestions at your own risk. The author nor anyone else guarantees any of the
procedures or tips below. The author nor any of the companies mentioned within will not (sic) be held responsible for any costs or
damages incurred as a result of attempting to upgrade a Transwarp.GS board.)
WDC created this document to help some special users of the Apple IIGS, journalists, consultants, engineers, and Apple Computer
experiment with faster Apple IIGS systems and faster W65C816 microprocessors. New applications will be found when higher speed
W65C816's exist. WDC also has engineering samples planned on other chips such as W65C02, the W65C134, and the W65C265 (when it
exists). Engineering parts are tested for extremes of voltage and temperature. Some engineering W65C816, W65C02, and W65C134
microprocessors have a specification of 1.2 volts (watch battery). In short, this is applications engineering information.
When the Mensch Micro Computer Company has boards out then WDC/Mensch will concentrate on the Mensch Micro Computer rather than the
Apple IIGS.)
Applied Engineering's Apple IIGS accelerator card, the Transwarp.GS, accelerates the IIGS to 7 MHZ. Even though AE does not
yet sell a faster board or offer an upgrade, it is possible to increase the speed of a TWGS beyond 7 MHZ. Some users have had their
boards running reliably as fast as 13 MHZ.
Yes, if you can't wait for an Applied Engineering upgrade, it is possible to upgrade the board yourself. Unfortunately,
despite what you might have heard or read in InCider magazine, THE UPGRADE IS NOT TRIVIAL! This is one reason why AE does not yet
offer faster boards.
By replacing the microprocessor and the oscillator on TWGS, you *may* be able to get a TWGS board up to 9 MHZ. To go any
faster than 9 MHZ, you will have to do a lot of messy soldering to replace 3 static RAMs and change the power supply.
If you don't have any experience working with this sort of thing or if you are not a technical person, we highly recommend not
attempting an upgrade like this. If you try the upgrade and you mess up your Transwarp board, you're on your own. WDC does not
guarantee these engineering parts and does not offer further technical assistance for these upgrades. If you blow a W65C816, you're
out $95. If you wreck your TWGS board, you're out $300.
Your TWGS board MUST have version 1.5 or greater to be able to run beyond 7 MHZ. Applied Engineering should provide a free
upgrade ROM for you (AE: 214-241-6060).
Below, then, are four upgrade steps. You need not carry out all the steps, but each step will allow your TWGS to run faster.
UPGRADE STEPS:
1. REPLACE THE CRYSTAL OSCILLATOR
The TWGS oscillator runs at 4 times the microprocessor speed (i.e., 28 MHZ for TWGS). You will therefore need to get an
oscillator 4 times faster than the speed at which you want the TWGS to run.
A "standard" TTL oscillator plugs into a standard 14-pin DIP socket. On TWGS, AE used a "1/2 TTL oscillator", which fits
into a smaller 8-pin DIP socket. Unfortunately, this oscillator is not yet widely available in a variety of frequencies.
Supposedly, several Asian companies make the 1/2 TTL oscillator, but parts seem difficult to find. One American company that
is supposed to make them is RXD (Nebraska: 1-800-228-8108). The part you want is called "RXD H-T-2". Unless they happen to have
the frequency you want (unlikely), they may require 6-8 weeks to make you a sample, if at all.
Your best bet is to get a standard TTL oscillator, which is bigger than the 1/2 TTL but has its four pins in the same
orientation as the 1/2 TTL package, and solder leads onto the pins to fit into the oscillator socket on the TWGS. Look for the dot
on top of the oscillator indicating Pin 1.
You can get standard TTL oscillators by calling local electronics suppliers. RADIO SHACK DOES NOT CARRY THEM. If you're
stuck, try Digi-Key: 1-800-344-4539 (Minnesota). They accept Visa/MasterCard. A 40 MHZ oscillator from Digi-Key is Digi-Key part#
X120; the 50 MHZ is X121. Each will run you about $6.00 plus shipping.
(you might want to get at least two oscillators in different frequencies to play around with different speeds.)
2. REPLACE THE MICROPROCESSOR
Because it requires no soldering, this is probably the easiest step. Western Design Center sells fast W65C816's in PLCC
packages (the one used on TWGS) for about $95 dollars.
WDC has two kinds of W65C816 parts that you can plug into a TWGS: "full-spec" parts and so-called "engineering parts."
Engineering parts are a bit faster than the full-spec parts, but they have some current leakage problems that may make a system fail
at lower clock frequencies (in the 100 KHZ range). An Apple IIGS running at 1 MHZ or faster should have no problem with this.
If you call WDC to order a fast W65C816, TELL THEM you are upgrading a Transwarp.GS board. Get an engineering part if WDC has
any; otherwise, get the fastest standard parts available. (WDC: 602-962-4545).
Each engineering part is INDIVIDUALLY screened for high speeds. Some parts run as fast as 13 MHZ (you will need to check with
WDC as to availability). For each engineering part sold, WDC supplies a "shmoo" plot.
The shmoo shows if the part passes its high speed test over a certain voltage range. The horizontal axis of the plot shows
the PHI2 cycle time against the VDD input voltage on the vertical. An 'X' at a point indicates that the part passed the test at
that voltage and cycle time. The operating frequency is calculated by: FREQ = 1/cycle time (denoted "TR" on the shmoo). Generally,
increasing the voltage will increase the operating frequency.
The W65C816 PLCC chip is normally removed from its socket with a special tool. However, you can remove it with a stiff wire
if you are careful. There are four holes on the PLCC socket, one on each corner. Carefully stick the wire into each hole and pry
the chip out. Pry it out a corner at a time until it comes loose.
Note that the PLCC package is specially shaped or "keyed" so that you can't plug the chip in sideways.
3. REPLACE THE CACHE SRAMS ON THE TWGS
The removable "piggy-back" board on the TWGS contains 3 8Kx8 static RAMs (SRAMS) and an EPROM. Unfortunately the three RAM
chips are soldered to the piggy-back board. You will have to de-solder the three chips from the board and replace them with 28-pin
DIP sockets. Note that you may destroy the RAM chips that are already on the board. Remove the EPROM before you start soldering.
SPEND THE EXTRA DOLLAR AND SOLDER IN SOCKETS INSTEAD OF SOLDERING IN NEW RAMS, then plug the new RAMs into the sockets. (Sockets:
Digi-Key part #C8928).
Most TWGS boards come with 45 ns static RAMs. You will need (probably) 20 or 25 ns RAMs to go any faster than about 9 MHZ.
If you want to get into the 13 MHZ range, be sure to get 15 ns RAMs.
Try local distributors, or look for ads in the back of computer magazines; many companies sell RAMs these days (Digi-Key does
not sell them) You want an 8Kx8 Static RAM, 28-pin DIP (Widebody), plastic package. Low power RAMs (as opposed to standard power)
are recommended.
The following companies manufacture fast 8Kx8 SRAMS: Toshiba, National (who just bought Fairchild), Integrated Device Technology
(IDT), Cypress, and others. Prices may vary from $12 up to about $30, so check around if you can. The faster RAMs and the low
power RAMs will cost more.
4. INCREASING THE TWGS POWER SUPPLY
(Warning: This step requires you to *cut* wire traces on the TWGS PC Board. Cut the wrong trace, and you could wreck your
board. Don't even *think* of attempting this step unless you really know what you're doing.)
The TWGS normally uses the Apple +5 volt supply. However, you can get a little more speed out of the board by increasing the
power supply voltage. You can use the + 12 volt supply from TWGS edge card and an adjustable voltage regulator to produce a power
supply voltage between 5-6 Volts. Make sure the voltage regulator is rated to at least 2 Amps; a 13 MHZ Transwarp card will draw a
lot of current! Be careful with the power supply; if you have other cards that use the + 12 volt supply, you could really be taxing
the supply. The Apple IIGS power supply is rated at 2.5 A at +12V.
How high should you adjust the voltage? If you got an engineering part from WDC, use the shmoo plot to determine what voltage
will allow the part to run at the speed you're aiming for. It is not recommended that you raise the supply higher than about 5.8
volts.
Note:
*DO NOT RUN THE TWGS HIGHER THAN 6 VOLTS OR YOU WILL DESTROY IT!!!*
You must disconnect the +5V supply in two places: near the edge card connector and on the DIP header cable (the little cable
that plugs into the IIGS microprocessor socket). Cut the trace on the front of the TWGS PC board from pin 25 on the edge card (this
is +5V). The trace is marked with a + on the TWGS. Also, cut the wire on the DIP header cable coming from pin 8 (VDD) on the
microprocessor socket.
There is no easy way to describe which wire is connected to pin 8. Use an ohm meter to find out which wire is pin eight on
the DIP header and cut that wire. You can also get the connectors to build a new cable. The IDC connector is a standard 40-pin
connector (Ansley 609-4030 or Circuit Assembly CA40-IDC). However, there are two kinds of 40-pin DIP headers. The one used on TWGS
is the less common type with the pin rows reversed. Try a Circuit Assembly CA-401DP.
HOW FAST CAN TWGS GO?
You should be able to get 8 MHZ out of *any* TWGS board by carrying out steps one and two; if you can find the 1/2 TTL
oscillator, you won't even need to pick up the soldering iron. Some TWGS boards could run at 9 MHZ by doing these steps (you will
need to try it for yourself) If you think the speed increase from 7 MHZ to 8 or 9 MHZ is worth $100, fine.
By carrying out the first three steps (replacing the RAMs as well as the CPU and oscillator), you should be able to get your
TWGS up to 10 MHZ.
To get into the 13 MHZ range, you will need to raise the power supply as described in step four. As noted there, be sure you
know what you're doing before you try this, or you could ruin your TWGS.
Remember that you must have TWGS firmware version 1.5 or greater to perform the upgrade.
IS IT RELIABLE?
The steps above are only part of the work involved in upgrading the TWGS. The rest involves testing your upgraded board.
Even if your newly upgraded TWGS works fine right after you turn on the power, it may not work flawlessly under all
conditions. Let the board run for a few hours until it gets warm. Try "worst case" conditions (the way you would normally use your
computer), *then* see how it works. Generally, raising the temperature of IC's reduces their performance. Note that
microprocessors and memory chips all vary a bit in their performance; some TWGS's may work better than others.
Run the TWGS desk accessory self-tests (the speed switch test may fail; this might be OK). Run software that you normally use
as part of the reliability test. If you have Appleworks.GS, try running that. Several people have claimed that this will really
prove whether a TWGS is reliable. Try running all the modules after the board gets warm.
Don't brush off this last important step. You wouldn't want to find out right in the middle of some important work that your
TWGS bombs when it gets hot.
If you find that your upgraded TWGS is unreliable, you may need to try a slower oscillator or a faster microprocessor (or
raising the supply voltage for those so daring).
IS IT WORTH THE EXTRA COST?
Users who upgrade their boards do so at their own risk. You may spend about $150 just to try. If you really don't *need* the
speed, wait for Applied Engineering to come out with an upgrade. In the meantime, try to appreciate how well your Apple IIGS
performs at 7 MHZ.
ORDER AND INFORMATION FORM
W65C816PL-ENG
Western Design offers faster W65C816 microprocessors for increasing the speed of the Transwarp GS card as a service to the public --
we are not set up for retail trade.
HOWEVER, THE FOLLOWING CONDITIONS MUST BE UNDERSTOOD:
-- We have engineering chips that sometimes test out at higher speeds than our normal "off the shelf" stock. These chips are
tested for the performance of that individual chip. Each one of these has its own shmoo (In other words, what voltage provides what
speed.) From these plots, we can sometimes find a few that run at 10 Mhz and up to 13 MHz.
(NOTE: FOR THE TRANSWARP.GS BOARD, VOLTAGE IS AN IMPORTANT FACTOR -- READ THE ENCLOSED SUGGESTIONS/WARNINGS).
-- Generally, we have engineering chips that have tested out at 10 Mhz at some voltage on the plot. As each order comes in, we take
the best looking plot to fill that order. If you place your order now, your order will be filled from current engineering stock.
If you would like faster, we can put you on a list for the next time we have an engineering lot tested.
-- Engineering chips cost $95.00 each -- due to limited numbers, we cannot guarantee availability.
-- We offer no guarantees or refunds on these chips; we know they work when they leave our door. Due to the sensitive nature of a
chip, WDC CANNOT BE RESPONSIBLE FOR DAMAGES THAT OCCUR AFTER LEAVING OUR FACILITY. Every precaution is taken by us to protect the
chip (i.e. anti-static packaging) while in our care and in our shipping methods.
-- Suggestions for upgrading your board are attached. We offer these as a way for you to pre-qualify yourself for the task. We
cannot help you troubleshoot problems. We have no technical support for the Transwarp.GS. YOU ARE ON YOUR OWN IF YOU DECIDE TO BUY
A W65C816-ENG.
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I would like to order the following:
W65C816PL-ENG (Engineering) QTY________________@ $95.00 = $______________________
Shipping QTY________________@ 3.00 = $______________________
Total $______________________
Please check one:
Amount is enclosed______________
Ship C.O.D> ______________
NAME_______________________________________COMPANY__________________________________
ADDRESS____________________________________CITY_________________STATE_____ ZIP______
Please put me on the "Priority List" for faster engineering chips to be notified when they are available. YES_______ NO_______
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Mike Aos Death to IBM!
East Grand Forks, MN (yeah, it's COLD up here) Are Amiga's really
| Woz | that bad?
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