Coleco Adam General Maintenance

Adam memory console, keyboard, controller and digital data packs (Akbkuku, CC BY 4.0)

Care, cleaning and the user-serviceable adjustments of the Coleco Adam: the digital data packs and drives, the SmartWRITER printer mechanism, the keyboard and the power supply. Most of the procedures come from Coleco's own System Check-Out and Trouble-Shooting Guide and Set-Up Manual. Fault-finding is on Coleco Adam Troubleshooting Guide and capacitor values on Coleco Adam Capacitor Replacement Guide.

General care

• Keep food, liquids and smoke away from the computer. Clean the keyboard, memory console and printer with a dry cloth.
• Do not connect a telephone line directly to an expansion port.
• Keep the vents in the cases clear; continuous paper must not block the vents at the back of the printer.
• Run the Adam from 108–132 V mains, on a circuit without motor-driven appliances. Coleco recommends a line conditioner or transient suppressor.

Digital data packs

Data packs look like audio cassettes but hold reel-to-reel tape in a Lexan case, up to 256 KB each.

• Take the data pack out before switching the Adam on or off, and never switch off or pull the plug while a pack is moving: data on it can be erased.
• Never remove a moving pack, and open the drive door only when the spindles have stopped.
• Insert the pack with the label facing out and the exposed tape downwards; the locating holes in the upper corners face the rear. Close the door by pressing both sides of its top frame. A noticeable push is normal, but do not force it; if the pack is in wrongly the door will not close.
• Keep packs away from magnetic fields, including TV sets, the printer, the memory console, refrigerators, vacuum cleaners and power tools. Store them in their cases, between 10 °C and 52 °C, away from dust.
• If the tape has run fully onto one spool, wind the empty spool back a few turns by hand; if it is wound unevenly, tap each side of the pack on a hard flat surface until it winds evenly.

Coleco advises saving important files twice, on separate packs, and keeping the SmartBASIC pack only for loading BASIC, since packs wear out.

Data drive

Cleaning the head and roller

1. Switch off and take out any data pack.
2. Check that the rubber roller turns freely: spin it gently with the eraser end of a pencil. Do not touch the tape head.
3. Clean the head by rubbing it with a foam-tipped swab moistened with isopropyl alcohol.
4. Leave the Adam off for ten minutes before using it again.

From Coleco's check-out guide.

Removing a data drive

Unplug the power cord and take out any data pack first.

1. Lift off the memory console cover: put a coin in the recess on the right side of the cover and twist it to prise the cover up.
2. Unplug the two cable connectors marked 1A and 1B, to the right of the expansion connectors, by pulling straight up on the cable.
3. Remove the three screws marked A, B and C (GROUND) and the two washers that hold the drive.
4. Holding the drive by the top, slide it forward and lift it out.

Refitting a data drive

1. Put the guide tabs on the bottom of the drive into the memory console.
2. Slide the drive into position so that its metal tab lines up over the hole marked C (GROUND).
3. Fit the screw in hole C, then the two washers and screws in holes A and B. Tighten all three, but do not overtighten.
4. Plug the drive's nine-pin connector into 1A and its eight-pin connector into 1B. Line the holes and pins up carefully: the drive will not work if a connector is misaligned.
5. Refit the cover: tabs on the left-hand side into the notches, then snap it into place.

From Coleco's check-out guide, which says to work carefully and consult a repair technician if in doubt.

Printer

The SmartWRITER printer (right).

The SmartWRITER is a daisy-wheel printer printing 10 characters per inch at 10 characters per second, on single sheets up to 9½ in wide or on fan-fold paper with the optional tractor feed. Keep fingers, clothing, hair and jewellery away from the mechanism. Switch off before any adjustment; some of them take moderate force.

Removing the cover

1. Make sure the print mechanism is centred and moves freely.
2. Grasp the rear edge of the print cover on each side.
3. Bow the centre of the far edge upwards.
4. Lift the far edge up to remove it. To refit, lower it fully with the near edge seated in the slots of the main cover.

Do not pull the print mechanism cable off its pulleys. Coleco warns that the tension is very hard to set again once the cable has come off.

Carriage and rods

• The carriage return switch sits to the left of the carriage. If its contacts are open even slightly, bend them carefully so that the upper bar is parallel to the base of the printer and the two contacts close properly.
• The rods the print mechanism slides on may need lubrication. Put a dry synthetic lubricant, Coleco names DuPont Teflon Dry Lubricant and Fuller Transmission Silicone Lubricant, on a clean rag and wipe the rods. Very little is needed. Do not use oil.
• Check that the carriage cable is tightly wound and that nothing blocks the full travel of the print mechanism.
• If the print mechanism is moved by hand during a print job, wait about 30 seconds before printing again.

Paper feed

• If the paper advance knob is tight, feed in half a dozen sheets together to ease it, and apply silicone grease to the serrated teeth on the inside edge of the knob, turning it several times.
• Keep the paper release lever towards the rear to stop the paper slipping, and use paper no wider than 9½ in.

Daisy wheel and print quality

Use a 96-petal daisy wheel with Coleco's character sequence. Check that it has no broken petals and that its square hole fits tightly on the peg of the print head; to reach it, press the two plastic latches under the ribbon plate towards each other and tilt the print mechanism up.

Coleco's print-quality adjustments, to be done carefully:

• Characters light at the top: bend the hammer assembly slightly forward with pliers. Light at the bottom: slightly backward. When it is right, fix it with two drops of cyanoacrylate glue at the point shown in the guide.
• Characters light on the left or right side: twist the hammer very slightly, checking the print after each adjustment.
• Part of the next character printed, or double characters: with the cover off and the power on, space the head to the centre of the page, type the underline character (SHIFT and 6), push the hammer striker forward with your thumb and check that it is centred on the underline petal. Bend it slightly until it is.

Keyboard

The keyboard has 75 full-travel keys on a membrane with rubber domes, and its own 6801 controller board. Leaded Solder's restoration found the frame held together with 7/32 in nuts, bolts and fold-over tabs, and a few small lock washers between the board and its RF shield that are easily lost; the membrane felt crunchy and was only rinsed, not scrubbed. Use the coiled keyboard cable: Coleco states that a telephone cable will not work in its place.

Power supply

The power supply for the whole system is a linear supply on its own board inside the printer, with a transformer, four regulated rails and large filter capacitors. The rails, tolerances and fault-finding are on Coleco Adam Troubleshooting Guide, and the full capacitor list on Coleco Adam Capacitor Replacement Guide. The transformer primary and switch carry mains voltage; unplug the printer before opening it.

Related pages

• Coleco Adam
• Coleco Adam Troubleshooting Guide
• Coleco Adam Capacitor Replacement Guide
• Coleco Adam Documentation
• Recommended Tools