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flashmemory instead of EPROMs

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Cluricaun

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EPROM 2 FLash

Hi

Have anyone replaced a EPROM with some of the flash cards available, like compact flash. I like to use a flashmemory instead of EPROMs.

The EPROM is used as storage in an old laptop with a Z80 processor. The EPROMs is both slow and expencive so I would like to use a flash eprom instead. The one I wanted to use is obsolete (28F008S5), but perhaps the cheaper CF cards can be interfaced?

Thanks in advance and every advice or help is welcome.
 

happy123

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Why CF Card? The form factors are different. You can get some newer version of EEPROM or Flash chip to replace your obsolete EPROM.

Look for 29F010 for example or something that fit into the same socket.
 

Zenner

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The new eeprom version, as w27c512 etc (45ns) faster then obsolete flash 150ns.
 

Cluricaun

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FLASH

Hi

Thanks for your help, the chip that where originally used was a Intel 28F008, 1MBx8. I think I found some replacement chips, for instance MBM29F080 from fujitsu. The computer uses 12 V as programming voltage VPP but these fujitsu is a 5V type, but that is quite easy to solve, I think. Boot sectors needs to be uniformely distributed (not at the top or bottom), this is supported with this fujitsu chip, so as far as I understand I can use this chip instead.
 

happy123

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I found this when doing a yahoo for "28F008 replacement":

http://www.intel.com/design/flcomp/applnots/29782802.pdf

You might want to compare the programming spec of the chips to be sure. From what you decribed, you laptop writes to the flash. Reading them should be the same, but if programming spec (algorithmn, voltage and timing) deviates then your laptop might have problem writing to it.
 

Zenner

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Re: FLASH

xs said:
The computer uses 12 V as programming voltage VPP but these fujitsu is a 5V type, but that is quite easy to solve, I think.
xs
No problem, pin 1 in 5v chips is n/c.
 

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