Represent items such as letters and numbers. Therefore it will take multiple bits used together to Obviously a single bit can only represent two states, Sixteen (16) bits together is called a WORD.Įight (8) bits together is called a BYTE.įour (4) bits together is called a NIBBLE. This is called binary because the bit can only have twoĭifferent terms. Numeric element used in a computer and can have the value of 0 orġ. The bit (short for Binary Digit) is the smallest The computer cannot store data in an EPROMīecause the EPROM is a READ ONLY memory part.ĮPROM, like any memory chip, is designed to store Once theĮPROM is programmed it cannot be changed until it isĮrased.
Product called an EPROM or DEVICE programmer. It must be programmed by a special programming Which will not forget its program or data when power is Information into the chip thus the term read That the CPU which is connected to the EPROM can Programmable means that the EPROM can be programmed with a program, We will talk moreĪbout erasing eproms later. A FLASH EPROM can be erased electrically and is the most current technology. An EPROM is erased in a deviceĬalled an EPROM eraser. No matter how new, all computers work this way.īe erased and reused. The I/O chip connects the CPU running the program to devices such as a keyboard and display or fuel injectors and a crankshaft position sensor. This is done via the INPUT/OUTPUT (I/O) chip. In order for a program to perform a useful function it must exchange (read/write) data with the real world. RAM allows both reading and writing of data EPROM only allows data to be read. If the program needs to save data from an intermediate calculation it will use the RAM (Random Access Memory) chip. Once that instruction has been executed the CPU gets the next instruction stored in the EPROM.
Once the CPU gets an instruction it interprets the binary code and performs the operation such as ADD, SUBTRACT, MOVE DATA, OUTPUT DATA, etc. The CPU gets the instructions one at a time by sequentially accessing memory (EPROM). A computer is a machine which executes instructions in a specific order (the program). However it does support the 2716, 2732 and MCM68764/MCM68766 perfectly well.The microprocessor (CPU) is the heart of a small computer, however in order to have a functional machine you need additional chips. However, I was very dissatisified with the way the tech support people dealt with problems programming the 27C400. Last year I purchased a BKPrecision 844USB which is compatible with just about every old chips that exists. You can easily program these on the inexpensive and very popular Willem programmer. These are very easy to find and can be programmed by just about anything. However, the 64c, C128, 1541-II, 1 ROMs which are directly pin compatible with 2716 EPROMs or OTP PROMs. The number of pins don't even match and the pinout is altogether different. Today these are extrmely difficult to find and can only be programmed on antiquated programmers or new but costly specialized programmers.ĭon't even think of reproducing a 2364 ROM onto a 2764. These can only be reproduced exactly (as in without an adapter) on 2732 and MCM68764/MCM68766 chips that have been discontinued long ago.
However, the VIC-20, original used 23 ROM chips. Since pretty much all Commodore 8 bit systems use antiquated 2332, 2364 or 23128 ROMs, the simplest EPROM burner/reader should do nicely.
What PC EPROM hardware/software combo would you reccomend for backing up 64/1541 ROMs? Also, what chips (27c16, etc) should/can be used for this?