Sharp PC-1500 Cartridge for debugging

For debugging purposes (and also for¬†playing around with memory chips on a bread board) I’ve created little breakout boards for the cartridge slot on the bottom of Sharp PC-1500s/1600s.

Sharp Debug Cartridge PCBSharp Debug Cartridge insertedI’ve added a layer of foam (not visible on the photo) on the bottom¬†side of the cartridge to prevent the pin ends from scratching on the case.

Typing on the PC while having cables connected to the cartridge is a bit annoying as I tend to pull off the cables when turning the PC around. I’m currently figuring out a better solution by using ribbon cables instead of the pins. I will update the post as soon I’ve managed to make photos of the modified version.


Sharp PC-1500 Interface Card / Breakout Board

Just a little update for all readers interested in Sharp 1500/1600 PCs: for hacking around with the Sharp Pocket Computers I’m using a self-made breakout board that allows easy access to all 60 pins of the interface connector.

Sharp PC-1500 Breakout Board (1)The 60-pin connector is a simple 1.27*2.54 60-pin male header (I’ve bought mine here).

Two LEDs indicate battery or power connection, and on/off state. (In most cases power lights up as soon as the board is attached to a Sharp PC.)

Sharp PC-1500 Breakout Board (2) Sharp PC-1500 Breakout Board PCBs

Suitable paper rolls for the Sharp CE-150 printer

It’s not that easy as it may sound to find paper rolls for a 30 years old printer, the Sharp CE-150. The printer is used in combination with a Sharp PC-1500/1500A pocket computer.

I’ve looked at my small amount of paper rolls, the leftovers¬†I’ve found in a box on the attic. Interestingly they were differing in size (can’t remember¬†why):

Sharp CE-150 Paper Rolls

(Left to Right) Core Diameter Tube Diameter Outer Diameter Width
Roll 1 7.7 mm 14.7 mm 28.5 mm 57.4 mm
Roll 2 8.3 mm 13.0 mm 29.3 mm 57.6 mm
Roll 3 11.1 mm 17.0 mm 33.0 mm 58.7 mm
Roll 4 9.7 mm - 19.7 mm 58.3

Their width¬†and outer diameters did not differ significantly, but the core diameters did. Paper rolls with core diameters of 7-9 mm are hard to get, the rolls sold today mostly have a diameter of 12 mm. I’ve successfully tested thermal (yes: thermal) paper rolls with this diameter in the CE-150, and these are really cheap to get (e.g. on eBay Germany). The ink doesn’t run, but there might be¬†paper rolls¬†with different coatings. I did not check that.

Maybe as a warning: Thermal papers mostly contain Bisphenol A (BPA), a substance that exhibits hormone-like properties!

The approximate dimensions you should look for are:
Width: 57 mm; Inner / outer diameter: 12 / 30 mm; Length: 10 m

Sharp CE-150 Still available paper roll (dimension)

Sharp CE 150 Printer (PC 1500) Vintage Hardware Repair

One weakness of the Sharp CE-150 printer unit is¬†the non-removal Ni-Cd¬†batteries. After 20 – 30 years now since their release they begin to leak. The battery acid (potassium hydroxide, a base, actually) will sooner or later destroy the circuit board and anything else inside the printer.¬†At that point the batteries are usually already dead and connecting a Sharp PC leads to “Error 78”, “Error 80”, or “Check 6″…

Sharp CE-150 Repair 3

Sharp CE-150 Repair 2

In case of such damages I usually use vinegar to clean up the case. Just put the case and any corroded parts (even if they are metallic) into a vinegar-water-mixture for a few minutes.

In case of circuit boards I’m using simple tap water and a brush to carefully remove the corrosion. Most parts on such a board can handle such a treatment. In this case I avoided getting water onto the relays and the ribbon cable. Afterwards drying the board is important, a regular hair dryer (or a temperature controlled hot air gun) will do.

Sharp CE-150 Repair 4

I’ve made a short video tutorial on how to open, check, and if necessary repair a Sharp CE-150 printer unit which is used in combination with Sharp PC-1500 / PC-1500A / PC-1600 pocket computers:

One final remark: the printer will run fine even without the batteries. These batteries were used to provide the 1 – 1.4 A peak current to drive the printer solenoid and motors. The old power supply that was shipped with the CE-150 only provides about 500 mA. You can attach a newer one that is able to provide sufficient current without problems (9 V, negative pole is in the center).

Sharp CE-150 Repair 5