7. EPROM Burners and Memory chips

Below is the information about EPROM and various types of memory chips.

7.1 Non-Volatile Memory chips

Here is the brief descriptions of memory chips and their types.

• PROM: Pronounced prom, an acronym for programmable read-only memory. A PROM is a memory chip on which data can be written only once. Once a program has been written onto a PROM, it remains there forever. Unlike RAM, PROMs retain their contents when the computer is turned off. The difference between a PROM and a ROM (read-only memory) is that a PROM is manufactured as blank memory, whereas a ROM is programmed during the manufacturing process. To write data onto a PROM chip, you need a special device called a PROM programmer or PROM burner. The process of programming a PROM is sometimes called burning the PROM. An EPROM (erasable programmable read-only memory) is a special type of PROM that can be erased by exposing it to ultraviolet light. Once it is erased, it can be reprogrammed. An EEPROM is similar to a PROM, but requires only electricity to be erased.
• EPROM: Acronym for erasable programmable read-only memory, and pronounced e-prom, EPROM is a special type of memory that retains its contents until it is exposed to ultraviolet light. The ultraviolet light clears its contents, making it possible to reprogram the memory. To write to and erase an EPROM, you need a special device called a PROM programmer or PROM burner. An EPROM differs from a PROM in that a PROM can be written to only once and cannot be erased. EPROMs are used widely in personal computers because they enable the manufacturer to change the contents of the PROM before the computer is actually shipped. This means that bugs can be removed and new versions installed shortly before delivery. A note on EPROM technology: The bits of an EPROM are programmed by injecting electrons with an elevated voltage into the floating gate of a field-effect transistor where a 0 bit is desired. The electrons trapped there cause that transistor to conduct, reading as 0. To erase the EPROM, the trapped electrons are given enough energy to escape the floating gate by bombarding the chip with ultraviolet radiation through the quartz window. To prevent slow erasure over a period of years from sunlight and fluorescent lights, this quartz window is covered with an opaque label in normal use.
• EEPROM: Acronym for electrically erasable programmable read-only memory. Pronounced double-e-prom or e-e-prom, an EEPROM is a special type of PROM that can be erased by exposing it to an electrical charge. Like other types of PROM, EEPROM retains its contents even when the power is turned off. Also like other types of ROM, EEPROM is not as fast as RAM. EEPROM is similar to flash memory (sometimes called flash EEPROM). The principal difference is that EEPROM requires data to be written or erased one byte at a time whereas flash memory allows data to be written or erased in blocks. This makes flash memory faster.
• FRAM: Short for Ferroelectric Random Access Memory, a type of non-volatile memory developed by Ramtron International Corporation. FRAM combines the access speed of DRAM and SRAM with the non-volatility of ROM. Because of its high speed, it is replacing EEPROM in many devices. The term FRAM itself is a trademark of Ramtron.
• NVRAM: Abbreviation of Non-Volatile Random Access Memory, a type of memory that retains its contents when power is turned off. One type of NVRAM is SRAM that is made non-volatile by connecting it to a constant power source such as a battery. Another type of NVRAM uses EEPROM chips to save its contents when power is turned off. In this case, NVRAM is composed of a combination of SRAM and EEPROM chips.
• Bubble Memory: A type of non-volatile memory composed of a thin layer of material that can be easily magnetized in only one direction. When a magnetic field is applied to circular area of this substance that is not magnetized in the same direction, the area is reduced to a smaller circle, or bubble. It was once widely believed that bubble memory would become one of the leading memory technologies, but these promises have not been fulfilled. Other non-volatile memory types, such as EEPROM, are both faster and less expensive than bubble memory.
• Flash Memory: A special type of EEPROM that can be erased and reprogrammed in blocks instead of one byte at a time. Many modern PCs have their BIOS stored on a flash memory chip so that it can easily be updated if necessary. Such a BIOS is sometimes called a flash BIOS. Flash memory is also popular in modems because it enables the modem manufacturer to support new protocols as they become standardized.

7.2 List of EEPROM Burner manufacturers

For a list of EPROM burner manufacturers visit the Yahoo site and go to economy->company->Hardware->Peripherals->Device programmers.

• Yahoo URL for EPROMs is at http://dir.yahoo.com/Business_and_Economy/Companies/Computers/Hardware/Peripherals/Device_Programmers/

• Advanced Research Technology B.V - development, production and sales of electronic programmer equipment; development of hardware and software.
• Elnec, Presov - manufacturers of programmers, emulators and simulators.
• Advin Systems Inc. - PC-based device programmers that support the latest in package types and device technologies.
• Andromeda Research Labs - manufactures a portable eprom and device programming system.
• B and C Microsystems, Inc - offers test and duplication/programming equipment for PCMCIA (PC) Cards, ISA/PCI Cards, SIMMs, Memory Devices (including FLASH), PLDs.
• BP Microsystems - Device Programmers.
• Bytek - designs, develops, manufactures and markets micro-processor-based, modular electronic systems used to program and test semiconductor devices. Product line includes the ChipBurner.
• Concentrated Programming Ltd - offers a full range of device programming solutions.
• Dataman Programmmers Ltd. - manufacture of hand-help EPROM programmer/emulator. Also sell PC-based programmers, and Gang-Pro programmers.
• General Device Instruments - IC Device programmers. Universal and Gang programmers for Pld, Flash, microcontrollers, Proms, EEproms, Memory, Epld, Mach and many other ic devices.
• HI-LO System Research Co., Ltd. - manufacturer of universal and gang device programmers.
• ICE Technology - EPROM and universal device programmers which support memories, microcontrollers, and programmable logic devices.
• Iceprom - in-circuit erasable programmable read-only memory.
• Incept Ltd.
• International Microsystems Inc - High speed reliable gang programmer. (PROM, FLASH, Microcontroller, PCMCIA memory card).
• JED Microprocessors Pty. Ltd. - plugs into a PC printer port D25 connector, and programs any 28-pin or 32-pin EPROM and FLASH device.
• Logical Devices, Inc - device programming for PLDs, FPGAs, PROMs, microcontrollers. Producers of CUPL compiler for programmable logic and the ALLPRO and Chipmaster device programmer.
• MCL Systems - new method not only for programming but also for developing your new hardware with Integrated Controller Unit. And you don't need to be an expert.
• MQP Electronics - manufacturer of universal device programmers, gang programmers, production software, and package converters. High thoughput and reliability.
• Needham's Electronics - manufacturer of device programmers.
• NP Programming Services - provides programming for memory and logic parts.
• Program Automation, Inc. - independent service company specializing in high volume PROM programming, including flash I/Cs.
• Stag Programmers Inc - manufacturer of prom and logic programmers, production handling equipment and UV erasers.
• Sunrise Electronics - universal device programmers, gang and in-circuit programmers with life time support.
• System General Co. - Device Programmer, EPROM Writer and IC Tester
• Tribal Microsystems - universal and gang device programmers, 8051 and EPROM emulators, test and burn-in sockets and production sockets.
• Universal Device Programmers