Apple also offered a different version of Applesoft for cassette users which occupied low memory and was started by using the LOAD command in Integer BASIC. The user could switch between either BASIC by typing FP or INT at the BASIC prompt. Disk users normally purchased a so-called Language Card which had Applesoft in ROM and sat below the Integer BASIC ROM in system memory. Apple instead licensed Microsoft's 6502 BASIC to create Applesoft BASIC. Because Wozniak was too busy developing Disk II hardware, he did not have time to modify Integer BASIC for floating point support.
As a result, it was less suitable to business software and Apple soon received complaints from some customers. Developed with game programmers and hobbyists in mind, the language only supported the encoding of numbers in a signed 16-bit integer format, between -32768 and +32767. This BASIC interpreter was written by Steve Wozniak to enable users to write software applications without needing to purchase additional development utilities. For example, users modifying or replacing the Android operating system describe files containing a modified or replacement operating system as " custom ROMs" after the type of storage the file used to be written to.Īpplesoft BASIC could be loaded from a cassette to replace Integer BASIC from early Apple II ROMs.Įarly Apple II ROMs were shipped with Integer BASIC encoded into the chips on the motherboard. The term "ROM" is sometimes used to mean a device containing specific software, or a file with software to be stored in EEPROM or Flash Memory.
Correction of such errors, or updates to the software, typically require new devices to be manufactured and/or replacement of the installed device.Įrasable programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM) can be erased and re-programmed, but usually this can only be done at relatively slow speeds, may require special equipment to achieve, and is typically only possible a certain number of times. Although discrete circuits can be altered in principle, through the addition of bodge wires and/or the removal or replacement of components, integrated circuits (ICs) cannot. Strictly, read-only memory refers to memory that is hard-wired, such as diode matrix or a mask ROM integrated circuit, which generally cannot be electronically modified after manufacture.
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