Offsets when burning different EPROMS

EPROM EEPROM SRAM NVRAM Flash chips, reading/writing hardware and software
vc81
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Re: Offsets when burning different EPROMS

Post by vc81 »

Thanks for explaining vl400. I didn't understand the difference between the upper case B & lower case b. Now I do. Thanks for explaining.
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antus
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Re: Offsets when burning different EPROMS

Post by antus »

Its worth noting that while thats technically correct people often dont use the correct case, so sometimes you need to infer what was meant from the info available.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
vc81
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Re: Offsets when burning different EPROMS

Post by vc81 »

Ok thanks antus
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Re: Offsets when burning different EPROMS

Post by tris909 »

thanks for the great info guys, now getting my head around it :thumbup:
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Re: Offsets when burning different EPROMS

Post by Dylan »

I'm completely new to chip burning, been using NVRAMS until now.
I stacked the 12P bin in tuner pro to suit my 512kb EEPROM. The file saved as 512kb in size.

I then burnt it and read it back. The read file saved as 64kb and reads ok in tuner pro.

Is that OK? Say if I was reading another stacked 12P memcal and wanted to burn it would I then stack that 64kb read?

Hope it makes sense, any feedback appreciated.
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Jayme
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Re: Offsets when burning different EPROMS

Post by Jayme »

I think you are confusing kilobit and kilobyte. A 27c512 is 512kilobit which is 64 kilobyte. (Kbit/8=kbyte) Windows works in kilobytes. Stack it as 64kb and burn that.
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Re: Offsets when burning different EPROMS

Post by Dylan »

Thanks Jayme sounds like i am i did read that above but makes more sense now.
Sense Windows shows it as 65kb perhaps it has stacked ok? 8X64 is 512 is that right?
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Holden202T
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Re: Offsets when burning different EPROMS

Post by Holden202T »

yeah that's the easiest way to remember it, 128kb chip = 128 / 8 = 16kb, 256kb, 512kb, 1024kb chips etc all the same calculation just divide by 8. and multiple the file size by 8 if you want to know what size chip you need to put them on.
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Re: Offsets when burning different EPROMS

Post by antus »

And yes, windows rounding and rough maths is why you see 65k. 1k = 1024 bytes. 64k = 1024*64=65536, so windows just incorrectly shows the 65 digits. If you stacked your original bin so many times it ended up as 512kb in windows, then only the first 64k would have been put on the chip, and since its was just the same data over and over and the object of the game is just to fill the chip up, you still achieved that, and the data still ended up in the right place so thats why it worked. But yes, it only needed to be 64k.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
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j_ds_au
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Re: Offsets when burning different EPROMS

Post by j_ds_au »

You should also be able to stack bins from the DOS command line :
copy /b xyz.bin+xyz.bin+xyz.bin+xyz.bin xyz4stack.bin
(no spaces around those plus signs)

Joe.
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