Can you use bigger sized EPROM?

protek

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I purchased JiffyDos binaries for my C128 and today got around burning the binaries on EPROMs. I did however hit a bit of snag as I'm not able to erase and therefore burn one of the 27128 EPROMs that I got. I've done several erase cycles on my EPROM eraser and I'm beginning to think the chip is duff.

I can't get a replacement until next week but I do have a good 27C256. Can I use a bigger capacity EPROM, if the binary is correct sized? Haven't got a glue whether the C128 will accept 256 kB.
 
Yes, it will work, but you will have to check what voltage is supplied to pin 27 (Address line A14) on the C128. If there's 5V on pin 27 then program the data to the second half of the EPROM, if pin 27 is connected to ground then program the data to the first half of the EPROM.
I suspect it will be at 5V.
Alternatively, just program the chip with 2x the data to fill the entire EPROM.

Bryce.
 
Thanks for the info! :)

Turns put that the third hour long erase cycle did the trick and I was able to burn the binary on it. Now I have JiffyDos for my C128. :)
 
Thanks for the info! :)

Turns put that the third hour long erase cycle did the trick and I was able to burn the binary on it. Now I have JiffyDos for my C128. :)

You do know that you suppose to use UV eraser not the Sun :). It takes less time :D
 
Thanks for the info! :)

Turns put that the third hour long erase cycle did the trick and I was able to burn the binary on it. Now I have JiffyDos for my C128. :)

You do know that you suppose to use UV eraser not the Sun :). It takes less time :D
I have this cheap Chinese UV eraser that seems to take its time erasing the chips. In general, how quickly should EPROMs be erased with an UV lamp?

And yes, it's been almost four years... :D
 
I have this cheap Chinese UV eraser that seems to take its time erasing the chips. In general, how quickly should EPROMs be erased with an UV lamp?
I would normally wait a couple of hours to be sure, even with a proper eraser.
 
my UV lamp bought on evilBay wasn't able to erase the chips right after purchase..needed to exchange the bulb, got a philips one, now it is done in 7 minutes..
 
I had to open my eraser to get one chip out. Turns out the bulb is in the front of the compartment. I've always put the chips back. Now when I left them in front, it gets the job done in 30 mins.
 
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