EPROM speed question

[Georg Hager <ghager@theorie3.physik.uni-erlangen.de>]

Hi all,

I have managed to get a 16k boot image run from a floopy -- everything
works fine. After burning the image.rom into a 27128 EPROM and plugging it
into my NE2000 clone (yes, it allows 16k), the client didn't recognize the
presence of the PROM and booted from the local disk. With DEBUG I found
out that the PROM did not appear at the memory location I had specified in
the NE2000 setup (D8000); all it reads there is 0xFF. If I remove the PROM
from the card, DEBUG reads 0x80 from those locations.

All this leads me to the conclusion that the EPROM is too slow for this
purpose. There are several hints in the archives, but no definitive upper
limit for access time. Unfortunately, my good old EPROM burner has a hard
time burning modern, fast CMOS EPROMS. It's still working with the Intel
algorithm (1ms pulses till data can be read, then one pulse with 4 times
the duration of all previous pulses together), and so has to stick with
the old, slow EPROMS (I'm thinking about adapting it to the AMD Flashrite
algorithm, but that would mean fiddling with the firmware; it's possible
because it's a self-built one, but if there's an easier way...).

So, my question is: has anyone succeeded in using 200ns EPROMS (the ones I
use at home)? Would it be an option to permanently pull the /CE pin to
GND, just working with /OE? This would maybe get me the desired 50ns
speedup....

Thanks,
Georg.

=========================================================================
Georg Hager             | Email:   ghager@theorie3.physik.uni-erlangen.de
Theoretische Physik III |                   Tel. (Uni): (+49)9131/85-8815
FAU Erlangen-N"urnberg  |                   Tel. (Pri):   (+49)911/735142
Staudtstr. 7            | Home URL:
D-91058 Erlangen        | http://theorie3.physik.uni-erlangen.de/~ghager/
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