The Sharp EL-6790/6890/6990 and YO/ZQ-160/180/190/270/480 Model Family


             EL-6990	                         YO/ZQ-180                    YO/ZQ-480


These electronic organizer models are Sharp's least expensive models with a serial communications port. There are less expensive models without a communications port, but organizers without a means of communication should be considered a toy unsuitable for serious use.

The first of these models was introduced in 1999. All of them share a common data format, serial interface, and communications protocol, although they differ broadly in price and appearance.

Model Differences

As you can see from the photos, there are 3 different appearances in this model family:

Model Memory
EL-6750, EL-6760, EL-6790, EL-6850 128 Kbytes
EL-6890, EL-6895, EL-6990, YO-270 256 Kbytes
YO-160 128 Kbytes
YO-180, YO-190, YO-480 256 Kbytes
ZQ-160, ZQ-165, 128 Kbytes
ZQ-180, ZQ-190, ZQ-195, ZQ-480, ZQ-485 256 Kbytes

YO and ZQ models are equivalent - Sharp uses ZQ internationally and YO in the USA for no known reason.

The suffix "B" or "P" on a model number indicates only the packaging: P = "Plus cable and software", "B" indicates "Basic", i.e. without cable and software.

Many other Sharp models may look superficially similar to these ones, but they are not part of the same family because they do not share the same data format, serial interface or communications protocol.


Data Types Supported (all models):

Additional data types supported on the YO/ZQ models but not the EL models except the EL-6990:

Other Functions:

These models use the same data format as earlier Sharp EL/YO/ZQ models, but the communication protocol is incompatible. That's not such a bad thing - the communication protocol of the earlier models had serious drawbacks, and Sharp has attempted to improve on it with these models.

The 3 modes of Telephone data are actually equivalent to the 3 separate Telephone files of earlier Sharp models. Only the name and the order of fields displayed is changed with the "Email" and "URL" modes. The Telephone data type of the older models does not include any additional "Notes" field or user-specified fields on these models, which could be a minor problem if you are transferring data from another model which does have such fields. The EL-6990 and YO-270 models add more Telephone fields (14 fields in all).

The password protection can be applied to selected items, an advantage if you don't want to have to enter a password to quickly access non-sensitive data. However the password protection on older Sharp organizers can be easily bypassed by someone with moderate expertise (no, we won't provide details), and the password system is sufficiently awkward to use that you probably won't use it regularly. Therefore no Sharp EL, YO, or ZQ model should be considered secure except against anything but casual snooping.

All models have a display backlight for use in low light conditions, although it should only be used very briefly since it drains the batteries quickly - an important consideration since the batteries are small and expensive.

Communications can be used only to exchange data with a compatible similar diary or PC backup program. There is no general communication capability.

These units cannot be programmed. There is no provision for user programming, or for downloading custom programs.

There is no graphics or sound capability (other than an alarm beep) – text only.

Good Points

These models are small and light enough to slip easily into a pocket. They support all the basic organizer functions. They have sufficient memory for most purposes. They support serial communications for data backup and exchange. They are relatively inexpensive, so they won't cost too much to replace if you lose one or break it. Therefore in many ways they are exactly what most people need in a basic pocket electronic organizer.

The serial cable for these models is inexpensive and easy to build yourself. You can buy the organizer with a cable for only a small price premium (usually about $10).

Not-So-Good Points

Sharp has improved some of the worst features of their traditional communications protocol in these models, but there remain a few significant limitations. For all except the newer model series YO/ZQ-270/290 and EL-6990, there is no way to exchange multiple data types at once, and you can only send or receive one new item at a time if you don't want to replace all items of that data type. There is no way to send multiple schedule items at once. These models do not support a true synch capability.

While the newer model series YO/ZQ-270/290 and EL-6990 have some improvements, they also introduce some new limitations which must be considered questionable design. They are limited to a maximum of 290 telephone records, and Memos are limited to 96 characters.

Although the serial cable is an inexpensive option, the software included with the cable is rudimentary. Sharp wants you to buy optional software at a price which is probably more than you paid for the organizer. Less expensive shareware software is available as an option.

As mentioned above, the secret password protection is not as secure on these models as with other organizer models. This could be a concern if you plan to store sensitive data.

The small batteries (CR2032) contribute to a slim profile, but they are getting to be very expensive to replace compared to the cost of the organizer. They need replacing approximately every 6 months, and it can cost you 15-30% of the organizer price just to replace the batteries.


These compact and inexpensive Sharp diary models are probably the best choice in a pocket electronic organizer for the purposes of most people. They handle all the basics well enough, they small and light enough to slip into a pocket, and they are not very expensive. You can pay more, but you won't get more until you arrrive in the $200+ realm of PDAs.

These models use a simpler and cheaper serial cable than most other electronic organizers (a first for Sharp!). The combined cost of the organizer and the cable could be an important factor in their favor if you are comparing to other alternatives such as the very similar Casio SF-49xx models.

Aside from some limitations in the communications function, the only significant drawbacks are the cost of batteries, and maybe the fact that it won't impress your high-tech friends like a color Palm PDA.

These models are currently widely available.