Computer Chip Help!!! EPROMS

[Warmaster199]

The serial number on the chip is 27C256. I know the "C" means that the chip is CMOS(Complimentary Metal Oxide Semiconductor) process instead of Bipolar. CMOS means it's a high-performance chip. The prefix 27 means that it's an EPROM memory of either 24 pins or 28 pins. Mine being the newer 28 pin EPROM. The last part tells it's capacity (ie. 256 means it's 256K something). In all, this serial number will tell you that the chip is an EPROM in CMOS process at 256K(bit or byte I'm not sure).

Here's the real question. When you talk about the chip itself, people say it's 32x8 organization. With this in mind, tell me if my EPROM is 256Kilobit or 256Kilobyte capacity.

Please note that a Kilobyte(1024Bytes) is 8(8Bits in a Byte) times more than a Kilobit(1024Bits).

Please reply telling me what capacity this EPROM is. I need to know. Thanks in advance.

[dsy5]

They would be the KiloBIT variety. The 32x8 organization says it all.

A 27C020 EPROM is the 256 Kilobyte variety. (256Kx8)

[Edited by dsy5 on 11-03-2000 at 08:00 PM]

[D12Bit]

I´m sorry, but the 27C256 is a CMOS with a capacity of
256K(ilobyte).

With 4 of this you will have 1024K = 1Mb.

I have used this to burn some code for diagnostic equipment
and the program that i did burn was approximatly 800Kilobytes.


Saludos...

[dsy5]

Originally posted by D12Bit
I´m sorry, but the 27C256 is a CMOS with a capacity of
256K(ilobyte).

I hope you're equipment worked...

It is not 256 kilobyte, it is 256 kilobit (32k x 8).
Read some documentation before you post; don't guess.

[Mad Compie]

Are you nuts?

Example: at work we use:
AMD27C010
[i]1024 kilo bits, i.e. 1024 bits/8 bits per byte, that is 128K bytes[i]

AMD27C256
[i]256 kilo bits, i.e. 256 bits/8 bits per byte, that is 32K bytes[i]

Note that EEPROM 28C010 can contain 128 K byte of data, but is VERY expensive and not easy to find (because everybody wants it!).

[dsy5]

Besides, it requires at least 17 address lines to read 256k and 8 data lines... plus Vcc,
GND, CE, C0... there's just not enough pins on a 27C256 chip(28)!

I think the largest I have personally burned at work are some AM27C040's (512k x 8)
- they are 32 pin devices.

[Edited by dsy5 on 11-04-2000 at 09:06 AM]