Hi Bill,

BG> What's the story with EPROM copying these days,
BV> The same as it's always been.
BG> Well that tells me a whole lot!  :)

Whoops. Sorry. I assumed you had programed them before.

BG> do you need highly specialised equipment, or what?
BV> Depends on what you consider "highly specialised".
BG> An EPROM burner, for a start.  I assume that's all that's required
BG> other than the usual PC and peripherals.

That's exactly what you need sorta kinda. Many industrial programmers
are stand-alone machines although they usually have a serial I/F
which allows you to either talk to them or command them from either
a terminal or PC. With this class of programmer, you don't need to
use the term/PC, it is simply an option if you wish to use one.
You can also get an adapter which plugs into an ISA slot and has a
ZIF socket mounted in a flash box at the end of a ribbon cable.
These are usually available for a couple of hundred dollars and you
have to drive them from your PC with the software supplied. This is
usually the low-cost way to buy a programmer although they are also
limited in what devices they can program. There are some rather
flash looking stand-alone programmers available now which look like
an oversized calculator and can program every device known to man,
including PALs, GALs, Serial EPROMs, FPGAs and god knows what else.

BG> The Sportie's EPROM appears to be a fairly standard 256Kb job, and
BG> I wonder, do they generally copy first time, every time without any
BG> problems?
BV> Hmmm...The EPROM in my Sportshoe is in a PLCC package and I don't
BV> have an adapter for it. I can blow standard DIP packages but not
BV> PLCC. Dieter used to have a gadget which would do PLCC stuff until
BV> he told them where to shove it. (Some people, no consideration for
BV> others)

BG> That's the one.  As you know, they have no UV window, so I presume
BG> that they are only electrically erasable (if at all).

I didn't know that there was no window, I hadn't bothered to look.
If it doesn't have a window it is more than likely a OTP device.
OTP = One Time Programmable.  They can be cheaper than EPROMs
although the way the market fluctuates, you'd need to check every
time you bought a batch, because sometimes you can get EPROMs cheaper.

Anyway, as the Sportshoe was aimed at the cost conscious end of the
market, there ain't no way that it would be an EEPROM. So it sounds
like you're up for the cost of a EPROM for starters. The biggest
problem you will have though is finding someone who has a PLCC
adapter which suits the device. They are not all that popular as
they cost a small fortune which means the very few people would buy
one for a one-off project or programming job. IOW, you're screwed.

BG> Also, can they be altered slightly, if required?
BV> Not a problem, provided you know where. Some are checksummed though
BV> and they can hide the checksum in a weird location which can make
BV> it a tad difficult.
BG> If the original ROM image can be saved to disk, then it is editable
BG> AFA I'm concerned.

True. That is what I meant. However, you may run into problems if
the EPROM is checksummed and you just start changing stuff.

BG> May not be necessary anyway.  The actual blank EPROM only costs
BG> a few dollars these days, I understand.  Is that about right?

Yeah, the EPROM itself won't be expensive but the PLCC adapter will be.

Regards, Brenton
@EOT:

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