> HARDWARE UPGRADE DETAILS
>
> This upgrade consists of replacements of the parts (chips) on the
> Zoomer's motherboard that are directly connected to and dependent of the
> clock source (crystal). This does not include the replacement of ROM, RAM
> chips or LCD screen since they can handle the new clock.
>
> The new clock is ~14MHz. We have a running prototype that was upgraded
> over six months ago. So far we did not have any problems with it.
> The only known downside of this upgrade is that the Zoomer's IR port
> when linked to the standard Zoomer (with the standard clock of 7MHz)
> is not functioning properly. In this case, if you are using Note Book's
> "Send page" or File Manager's "File Linking" after the time-out period,
> you will get the following message:
>
> "Could not establish a connection to the remote machine..."
>
> This is due to the way the Zoomer's IR port driver is written. This
> driver obviously uses processor cycles to set the timing for the IR port
> serial communication. Any program written in such way that it uses
> processor cycle timing as the time reference may not run as it suppose to.
> After the upgrade, the processor cycle duration is one half of the cycle
> duration of the non-upgraded unit. Therefore, the timings of the IR port
> are changed, and the old unit would not recognize the new one and vice
> versa. This problem can be solved by rewriting a portion of the driver
> that is responsible for the IR port timing. This would take the
> significant amount of time since it would be necessary to use a disassembler
> and find and change the portion of the code. The other easier solution is to
> use two units that are both running on the same clock speed. We found that
> as long as both units are running on the same clock IR port communication
> s working OK. Since the IR port timings are directly dependent of the
> processor clock, the IR port transfer rates are now running twice as fast
> on the Zoomers that are upgraded. The RS-232 port is working OK with the
> new clock and we did not find any problems with it. Due to the fact that
> the Zoomer does not uses processor cycle timing to run the real-time clock,
> therefore the time (duration of the seconds) is the same as it was before
> the upgrade.
>
> Since we do not change the type of the CPU, the new upgraded Zoomer
> is 100% software compatible with the regular one, and it will run all the
> software that regular Zoomer would run.
>
> For more info or for the upgrade order form, drop us a line.
>
>----------------------------------------------------------------------------
> E L E C T R O N I C S I N N O V A T I O N S
> 1149 East Desert Inn Road, Suite 9001
> Las Vegas, NV 89109
>
> Contact: apopovic@cs.unlv.edu
>----------------------------------------------------------------------------
>
>
>