Rom(Read Only Memory)唯讀記憶體,這種記憶體(Memory)的內容任何情況下都不會改變,電腦與使用者只能讀取保存在這裡的指令,和使用儲存在ROM的資料,但不能變更或存入資料。ROM被儲存在一個非揮發性晶片上,也就是說,即使在關機之後記憶的內容仍可以被保存,所以這種記憶體多用來儲存特定功能的程式或系統程式。ROM儲存用來啟動電腦的指令,開機的時候ROM提供一連串的指令給中央處理單元進行測試,在最初的測試中,檢查RAM位置(location)以確認其儲存資料的能力。此外其他電子元件包括鍵盤(Keyboard)、計時迴路(timer circuit)以及CPU本身也被納入CPU的測試中。
可抹除可編程唯讀記憶體(Erasable Programmable Read Only Memory,EPROM)可利用高電壓將資料編程寫入,但抹除時需將線路曝光於紫外線下一段時間,資料始可被清空,再供重複使用。因此,在封裝外殼上會預留一個石英玻璃所製的透明窗以便進行紫外線曝光。寫入程式後通常會用貼紙遮蓋透明窗,以防日久不慎曝光過量影響資料。
OTPROM
一次編程唯讀記憶體(One Time Programmable Read Only Memory,OTPROM)內部所用的晶片與寫入原理同EPROM,但是為了節省成本,封裝上不設置透明窗,因此編程寫入之後就不能再抹除改寫。
EEPROM
主条目:EEPROM
電子抹除式可複寫唯讀記憶體(Electrically Erasable Programmable Read Only Memory,EEPROM)之運作原理類似EPROM,但是抹除的方式是使用高電場來完成,因此不需要透明窗。
^Apple II的AUTOSTART ROM內所含監督程式 (System Monitor或Monitor II)的完整原始碼組譯列表係公開,內容可參見Apple II Technical Manual一書,Apple Computer, Inc.版權所有,1978年版見C. Apple II Firmware, 4. Annotated Monitor and Dis-assembler Listing章節,1979版見Appendix C ROM Listings章節。
^IBM PC與IBM PC/XT的BIOS ROM內所含BIOS程式的原始碼組譯列表係公開,內容可分別參見IBM公司發行的IBM PC Technical Reference與IBM PC/XT Technical Reference技術手冊。
Place in Moyen-Ogooué, Gabon Lambaréné Street in Lambaréné Lambaréné Location in Gabon Coordinates: 0°41′18″S 10°13′55″E / 0.68833°S 10.23194°E / -0.68833; 10.23194 Coordinates: 0°41′18″S 10°13′55″E / 0.68833°S 10.23194°E / -0.68833; 10.23194 Country Gabon Province Moyen-Ogooué Population (2013 census) • Total 38,775 Lambaréné is a town and the capital of Moyen-Ogooué in Gabon. With a population of 38,775 as of 2013, it is located 75 kilometres south of the equator. Lambaréné is based in the Central African Rainforest at the river Ogooué. This river divides the city into 3 districts: Rive Gauche, Ile Lambaréné and Rive Droite. The Albert Schweitzer Hospital and the districts Adouma and Abongo are located on Rive Droite. The districts Atongowanga, Sahoty, Dakar, Grand Village, Château, Lalala and Bordamur build the Ile Lambaréné. The majority of the people in Lambaréné live in the district Isaac located on Rive Gauche. This distr...
This article is about the number. For the year, see 800. For other uses, see 800 (disambiguation). Natural number ← 799 800 801 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 → Cardinal eight hundred Ordinal 800th (eight hundredth) Factorization 2 5 × 5 2 Greek numeral Ω´ Roman numeral DCCC Binary 1100100000 2 Ternary 1002122 3 Quaternary 30200 4 Quinary 11200 5 Senary 3412 6 Octal 1440 8 Duodecimal 568 12 Hexadecimal 320 16 Vigesimal 200 20 Base 36 M8 36 800 ( eight hundred ) is the natural number following 799 and preceding 801. It is the sum of four consecutive primes (193 + 197 + 199 + 211). It is a Harshad number. Contents 1 Integers from 801 to 899 1.1 800s 1.2 810s 1.3 820s 1.4 830s 1.5 840s 1.6 850s 1.7 860s 1.8 870s 1.9 880s 1.10 890s 2 References Integers from 801 to 899 800s Main article: 801...