V sredini junija 2000 so se pojavile govorice, da so nekateri problemi, povezani z 8MB RAM moduli na PalmOS kompatibilnih dlančnikih. Na nekaterih spominskih modulih se je občasno pojavilo prepisovanje enega 2k bloka z drugim ob osveževanju dinamičnega RAM. Možnost prepisa posameznega bloka je (bila) približno 1/8000, ko je RAM poln, osveževanje, pri katerem pride do napake pa se vrši enkrat na minuto (oh ja, kje so časi, ko je bilo potrebno DRAM osveževati vsakih 50ms). Kljub trditvam, da se v 8000 minutah napaka zagotovo pojavi, pa nam verjetnostni račun pokaže drugače.

Vrjetnost, da je cikel uspešen, je 7999/8000. Verjetnost, da je n zaporednih ciklov uspešnih je (7999/8000)^n. Torej je približno 36,69% verjetnost, da je vseh 8000 ciklov uspešnih oz. 63,31% verjetnost, da je eno osveževanje naredilo napako.

Handspring je pripravil popravek do konca julija, vendar pa se je v mojem primeru izkazalo, da je poraba baterij na Visorju mnogo večja kot prej. Zato sem se odločil za zamenjavo.

Zamenjava Visorja v ES ni nikakršen problem, je pa kar problem, če želite zamenjavo opraviti v Sloveniji (k sreči sem bil tedaj ravno v Nemčiji). Vse kar sem moral storiti je bilo, da sem poslal faks s kopijo računa na Nizozemsko in v nekaj dneh me je že čakal nov (ne obnovljen) Visor. Celo baterije so bile v paketu.

In the mid of Jun 2000 some roomers arrive, that there are some problems with 8M RAM modules in all PalmOS compatible palmtops. There was some issue with potential overwriting of 2k segment of the dynamic RAM at refresh time. Probability block to be damaged is (was) approx. 1/8000 when RAM is full. Refresh is done once per minute (good old days when DRAM was refreshed every 50ms). Although there was roomers, that in 8000 minutes error surely shows up, probability calculus shows another picture.

Probability, that refresh cyclus comes through is 7999/8000. The probability that also in second cycle RAM remains undamaged is 7999/8000 * 7999/8000. In n minutes it is (7999/8000)^n probability, that all refresh cycles leaves RAM uncluttered. To conclude: it is around 36.69% probability that RAM remains undamaged after 8000 cycles or 63.31% that it has been once overwriten in 8000 minutes.

Handspring has prepared a patch till late July. I installed the patch and soon after that noticed that my Visor has much higher battery drain as usual. So I decided top try to exchange the damaged unit.

It is not problem to exchange unit in EU, but it is quite a problem if you want they send you to Slovenia (luckily I was in Germany those days). All I had to do was to send them a fax with copy of the bill and in few days I had new (not refurbished) Visor. Imagine! There were also batteries included in a package.