Density Enhancement for
Atari 1050 Disk Drives
Note -- throughtout this manual:
SpartaDOS, SpatraDOS Construction Set, UltraSpeed, US Doubler, R-Time8,
RAMBO XL, and P:R: Connection, are trademarks of ICD Inc.
Atari 850, 130xe, 800xl, and 1200xl, are trademarks of Atari Corp.
Chapter 1 -- US DOUBLER OPERATION
The US Doubler is a high quality enhancement chip set for the Atari 1050 disk drive. Many man
hours have been spent to make this product easy to install and to provide your 1050 with
intelligent single, dual, and enhanced density operation. The US Doubler is an original,
innovative product developed by ICD, Inc., not just a poor copy of someone else's product like
some other density doublers.
After installation, your US Doubler 1050 will be fully compatible with the single and dual
density software which you have used before, as well as full double density operation with
programs which support that mode.
SpartaDOS, also developed by ICD., is the recommended DOS to use with the US Doubler since it
opens up the UltraSpeed operation. (Without SpartaDOS, your US Doubler enhanced 1050 will run
at normal speed.) This high speed data transfer is accomplished by increasing the SIO baud rate
from 19.2K to 54K. The UltraSpeed sector skew then allows 3 times as many sector reads for each
revolution of the disk resulting in rapid I/O which sounds like machine gun fire.
Possible Problems with UltrsSpeed and the 130XE
Some 130XE computers have been found which don't like the 54K baud rate and they seem to sputter
when reading a sector in UltraSpeed. The solution for this problem is to remove the band width
limiting capacitor on the data out line inside your computer. This capacitor (which looks like
a diode) will be connected from pin 5 of the 13 pin SIO connector of the 130XE to ground. All
you need to do is cut one end of the capacitor and bend it away from the rest. (When facing the
back of the computer, pin 5 is in the bottom row, the third pin from the left.) You will notice
that each pin on this connector has these capacitors going to ground. The purpose is to filter
out a small amount of high frequency noise which may affect television reception. The intention
was good but the capacitor on pin 5 also filters out high speed data.
NOTE: the newest 130XEs no longer have these capacitors soldered directly to the
connector. Instead, they have them properly laid out on the circuit board to the lower right of
the I/O connector. The capacitor you need to cut is C304.
SpartaDOS is available on disk as part of the SpartaDOS Construction Set for $39.95 retail or in
the SpartaDOS X cartridge (hardware version) for $79.95 retail. See your dealer or call ICD
direct for further information.
Chapter 2 -- US DOUBLER INSTALLATION
The US Doubler consists of two plug in modules which are to be installed in your Atari 1050 disk
drive. One of these is a 24 pin chip (U10) and the other is a hybrid 24 pin module (U8). These
are to be installed into the corresponding sockets on the 1050's Printed Circuit Board (PCB).
Atari is currently selling 1050s with two different types of U10 chips. The replacement U10
supplied by ICD, is the most common type found. If it is the wrong type for your drive, send us
your ICD - U10 for an exchange with the other type (recommended).
Be sure to fill out your warranty/upgrade card and mail it in. This will qualify you for a free
subscription to our OPEN FILE newsletter. It is also the only way we will be able to notify you
of changes and updates, and the only way you will be eligible for upgrades. Please, take the
time to fill in your Atari dealer's name and address, so we can make him aware of our products
for the Atari.
If after reading these instructions you feel this installation is not for you, then talk to your
local dealer or service center about it, or send us the drive. ICD will install this product for
$15.00 including UPS ground shipping one way. This low price is good only before you attempt to
install the US Doubler. For later services, see our prices at the end of this chapter. For
installation by ICD, send and mark the box to:
1220 Rock Street
Rockford, IL 61101-1437
Attn: 1050 Install
Please include a check for $15.00, the complete drive less cable and power supply, and the ICD
product. Our turn around is generally 48 hours.
Do You Still Want to Install It?
#2 Phillips head screwdriver
#1 Phillips head screwdriver (for some drives made in Hong Kong)
Medium or small flat blade screwdriver
A permanent ink marking pen for marking connectors during disassembly
An empty dish for holding parts
A clean well-lighted work surface
Small needle nose pliers
20-35 watt small tipped soldering iron (optional)
and the 1050 layout Use back button after viewing.
Let's Get Started!
Turn the 1050 on its back and remove the 6 Phillips head screws. (4 are recessed and 2 are on
the front bezel.) Place the crews into your parts dish.
Carefully turn the drive back onto its feet and set it down. Lift the rear of the top cover about
1/2 inch, slide it towards the front and lift the cover and bezel off as one piece. Set these
Things To Look For
Notice how the drive assembly sits in the case and note the four black rubber washers under the
drive frame. These usually fall out when removing the drive. (Hong Kong drives have these glued
down.) On the early 1050 drives, there are also four steel pins at the center of these washers
which fall out during disassembly (they are glued in on the later drives.) Notice the wires
which connect the drive to its PCB towards the rear. These should all be marked with J14, J10,
etc. on the connectors. The markings correspond with the markings on the PCB but they don't
always indicate the proper polarity. Take your marker and draw a line across the inside of each
connector. We will then know when we plug them back in that the side with the black line goes
towards the center. Do the same on all other connectors (there is one under the front of the
drive frame). We are now ready for the heavy work.
Important: Some Hong Kong drives have connectors with no markings and color coded wires.
If this is your situation you will need to make a chart indicating the color pattern for each
connector if you unplug them.
If you are selling or installing a large number of US Doublers, you may want to carry extra parts
in inventory to help your customers. ICD U10s and adapter sockets are available (direct from ICD
only) to stocking dealers.
Here Goes Nothing...
Remove the Drive(optional)
Experience has shown that more problems are usually created by unplugging the drive from the
circuit board than are prevented. The recommended procedure is to leave the drive mechanism
connected to the circuit board and to lift it up to access the board.
Take care, though, as the wire are small and will break if too much stress is applied. You
should still unplug J6, the drive head connector towards the front of the PCB. Notice that the
red conductor on J6 goes towards the front of the drive. If you choose to leave the rest of the
drive wires plugged in (we do), then proceed to Remove the PCB, otherwise, read on.
If You Wish to Unplug the Drive from the PCB...
Carefully unplug all seven connectors while noticing their positioning. Don't pull on the
wires; Do pull on the plastic connectors. A small needle nose pliers can make this easier
for tight fitting connectors. After removing the wires, lift the drive frame up and out of the
case and set it aside. Put the four rubber spacers and the four steel pins (if they're loose)
in your parts dish.
All 1050 Disk Drives
Experience has shown that more problems are created by unplugging the drive from the circuit
board than we thought would be prevented. The recommended procedure now is to leave the drive
mechanism connected to the circuit board and to lift it up to access the board. Be especially
careful not to damage the head leads wires which plug in at the front of the board. (You may
wish to unplug this one connector for easier asscee.)
At Last the PCB!
Remove the Printed Circuit Board (PCB)
You are now looking at the PCB. The chips (ICs) to be replaced are under that large tin cover
(shield) which is fastened on the foil side (the bottom side) of the PCB with twisted metal tabs.
This shield was designed to reduce RFI (interference with TVs, radios, etc.). The PCB is held
down to the case with either two plastic tabs (Singapore models), or four plastic tabs and three
small Phillips head screws with three brown insulating washers (Hong Kong models). If you have
screws holding the board down, remove these first. Then, lift the front of the PCB while bending
back the tabs with your other hand or screwdriver. The PCB needs to go slightly towards the front
and then out of the case! Place the PCB with its component side down on your work area. (If the
drive is still attached to the PCB you begin your balancing act.)
Remove the Metal Shield
The bottom shield on the foil side of the PCB is symmetrical but the top shield has a notched out
area in one corner. This notch is for clearance of the soldered connections on components R43 and
U14. Straighten the tabs and remove the two shields. Turn the PCB over, component side up, and
get ready for fun. (If the drive is attached, you should lift it off the board with one hand while
working with the other.)
Remove the Old ICs
The two 24 pin ICs, U8 and U10, must be removed. Use the flat blade screwdriver and gently pry
the chips out of their sockets and set them aside. These two will not be used again.
Check the Jumpers!
This is the most important installation step where most mistakes are made, so pay
attention! JP1 through JP7 are the jumper wires behind U10 (see diagram). In most installations,
only some of the JP (jumper) numbers will be visible. The other numbers are usually hidden under
the jumpers themselves. These jumpers might be solid pieces of wire soldered between two pads, a
wire with a white ceramic covering around the center or they might look like resistors with black
stripes. It does not matter which type is installed; they all serve the same purpose. The
position of the first four jumpers (JP1-JP4) determines which type of U10 chip you will need.
We're not really sure why Atari used the jumper system when the 1050 drive was designed. Maybe
it was so they could switch chip types when one became more cost effective. There are many
manufacturers of both types of chips and each works a well as the other for this application.
The only difference is pin configuration, which is what the jumpers change.
If the replacement U10 does not have a label, JP2 and JP4 should be open (no connection);
JP1 and JP3 should be closed (jumpered). If the replacement U10 has a paper label on it,
then JP1 and JP3 should be open (no connection) and JP2 and JP4 should be closed (jumpered).
Every effort has been made by ICD to provide you with the most common type of U10 chip.
We have found that most drives 'Made in Singapore' need the U10 without the paper label and most
'Made in Hong Kong' need the U10 with the label. The U10 which comes with the drive will match
the corresponding ICD U10 needed.
If your replacement U10 is of the wrong type, you have two options:
Plug in the Chips
- Send us the ICD U10 (in protective packing) along with $1.00 for shipping and handling
and mark on the outside 'Attn: U10'. When we receive this, we will send the other type
of U10 which you can then plug in. (If the pins are damaged on the returned IC, you will
be charged $7.00.)
- Move the jumpers to their correct locations for the ICD U10 chip in you possession.
Do not attempt this modification unless you feel confident with a soldering iron. Foil
trace damage may result from sloppy de-soldering techniques which will result in a
non-operational drive. The other jumpers JP5 through JP7 should always remain unmoved.
For correct positioning, the notches at the ends of the modules (chips) go towards the front
of the drive. Also, as a general rule, any labels or writing on your ICD replacement chips will
read from the front of the drive to the rear. Carefully plug the new U8 (the larger module)
into the socket for U8. Next, carefully plug the new U10 into its socket with the notch towards
the front of the PCB. Make sure all the pins went into the correct holes in the sockets and are
plugged in firmly. Wasn't that easy?
Drives made in Singapore
As a rule, these drives will have a "no label U10" installed. If true, then that is
the type from ICD which should be installed. Remember, when the jumpers are installed at 1 and
3 you need a "no label U10"; when the jumpers are installed in 2 and 4, you need a U10
with the white paper label. There is no other difference between these two ICD chips other than
the jumpers must be installed correctly for the respective U10.
A number of drives from Singapore have been discovered with "defective" sockets in the
U8 position. These can be identified by the numbers "41000" and "MXS-nn" molded
into the plastic (where "nn" represents a number like 12, 9, 15, etc.). These sockets
have large ridges which hold the ICD U8 module out of the socket and prevent proper pin contact.
The U8 module will feel loose in the socket. If you find yourself with one of these sockets it is
recommended that you send $4.00 in an envelope addressed to ICD, Inc. Attn: U8 Socket. We will
send a special socket adapter which will allow simple installation. The only other alternative is
to replace the socket (which means de-soldering and possible damage).
NOTE: This adaptor socket is not needed with the majority of Singapore drives nor
with any of the Hong Kong drives.
Drives made in Hong Kong
All of these drives (we have seen so far) have the U10 with a paper label installed (jumpers at 2
and 4). Replace this with the paper labeled ICD U10 or else move the jumpers to 1 and 2.
NOTE: ICD will send you the correct U10 for your drive as long as you send the old one
back for an exchange rate of $1.00.
Send it to ICD, Inc. Attn: U10 Replacement.
If you are selling ar installing a large number of US Doublers you may want to carry extra parts
in inventory to help your customars. ICD U10s and adaptor sockets are available (direct from ICD
only) to stocking dealers.
Put the Shield Back On
If you're unsure of what you are doing then you might want to leave the metal shield off for testing.
If you haven't had any problems following us so far then it's all down hill from here. Be careful
installing the shield and make sure the notched end of the top piece is over R43 and U14. Also,
make sure that no components or wires are pinched between the shield and the PCB.
Put the PCB Back into the Case
Place the rear in first, then lower the front of the PCB. The PCB should easily snap in place
under the plastic tabs. (Install the three washers and screws if your drive had them.)
Reinstall the Rubber Washers and Steel Pins (if removed)
Press the four rubber washers with the recessed side down, onto the plastic posts in the front
half of the drive's case. The four steel pins are either still stuck in the plastic posts or, if
they were loose (older drives), in your parts dish. Put one into each hole at the center of the
Reinstall the Drive Frame
Plug the rest of the connectors onto the corresponding pin locations. Be sure to note the marking
you made on the connectors during disassembly. (If you did not unplug your drive from the PCB,
you can skip this instruction. That's your reward for being so brave and talented.)
Replace Top Cover
To replace the top cover, line up the bezel over the front of the drive frame, then lower the
cover. If the bezel becomes separated, put the top cover on first, then hook the top of the bezel
under the top cover front edge, and gently snap it down into place. While holding the case
together turn the disk drive upside down and lay it on its back. Screw the six Phillips screws
back into place and presto!
START-UP AND TESTING
Plug the drive back into your system. If you're going to use UltraSpeed (US), it is usually best
to make this drive number one. Put a SpartaDOS Master disk into the drive, close the door, and
power up the computer. If you get an error message 'not an XL/XE computer', use the other Master
disk. Impressed? The MASTER SpartaDOS diskettes are single density US format. The first few
sectors are read at normal speed upon boot; the software determines whether the drive can handle
UltraSpeed and then loads the high speed code into your computer. Even though double density
sounds slightly slower than single density, the double density US format is even faster since it
is working with larger sectors. Refer to the SpartaDOS manual for more information about
operation and formats.
If it Doesn't Work
Go over the instructions again and check your work. There is probably something you have overlooked.
All of out products are thoroughly tested before shipping to ensure high reliability.
If the U8 module is in backwards or not making a good connection, if the jumpers are in the wrong
position or if the traces were damaged during de-soldering, the power light will come on but the
drive will not spin. If your drive won't boot the master DOS disk then try a standard boot disk
of known quality. If you still can't get it to work, send your complete drive to us for repair.
Our service turn around time is generally 48 hours. If there is a problem with our parts, there
will be no charges. If there is a problem with your installation, you will be charged a $25.00
flat rate including shipping. If there is a problem with the drive itself, our standard service
rate is $40.00 plus parts and shipping. In any case, we will send the repaired drive back to you
via UPS COD or prepaid if you include your VISA/MASTERCARD number. For repairs, send the drive
and mark the box to:
1220 Rock Street
Rockford, IL 61101-1437
Attn: 1050 Service
Be sure to completely fill out and return your warranty card. This is the only way you will be
eligible for future updates or enhancements. The warranty is not transferable and is intended
for you as the end user only.
Warning! The warranty will be considered null and void if the copyright labels are
removed from the ICs or if the hybrid module has been tampered with. We do not support
'pirates' (a nice word for thieves dealing in computer software and hardware; we use other words).
We own the copyrights for all our products including SpartaDOS. Any users who are found to be
selling or giving away copies of our products forfeit all rights to any support or service.
Furthermore, we will take legal action against those users if we feel it necessary or
Though the US Doubler is optimized for operation with SpartaDOS, any 'Atari Compatible' DOS
should function with it properly. When changing from SpartaDOS to another brand of DOS and using
the format command, first turn the drive power off and then back on (cold start) to re-initialize
the internal format settings. Failure to do this could create format errors with the other DOS.
The US Doubler (board layout, code & info) ...
Jeżeli ktoś jeszcze posiada stację dysków Atari 1050 bez przeróbek, to polecam zainstalowanie tej.
Sorki, że tekst jest po angielsku, ale nie chciało mi się tłumaczyć.