Problems burning Kickstart

[SnkBitten]

Originally Posted by nogginthenog

Success! I've programmed 2 EPROMS. 1 was erased (it failed first time), 1 out of the package.
Not 100% sure what is happening yet.

A 3rd EPROM failed twice. Maybe it needs longer in the eraser? Will try some more tests tomorrow.

Also, I successfully programmed a 27256 EPROM (no adapter needed). Don't have any other types of EPROMs to test.

Glad you had success. I'm positive mine is a hardware problem. Erased 4 EPROMs for 50 minutes, tried them and same failure as before. Opened up the other 6 blank EPROMs I have, same exact failure.

And I just damaged a chip by snapping off a few legs trying to make sure it had good contact as their Youtube video demonstrates the "proper" way to insert the EPROMs.

Very frustrating.

[Jope]

Please don't erase EPROMs for 50 minutes.. They can be over erased and will no longer hold data. Only apply UV radiation until it's empty. I tend to blank check mine every 5 minutes, but 15 mins is probably still safe.

[dJOS]

Originally Posted by Jope

Please don't erase EPROMs for 50 minutes.. They can be over erased and will no longer hold data. Only apply UV radiation until it's empty. I tend to blank check mine every 5 minutes, but 15 mins is probably still safe.

My thoughts exactly, the small Rom chips (256k) only need about 5 mins and the 1mb chips no more than 15 mins.

[idrougge]

Originally Posted by nogginthenog

Really? Damn. I don't really want to take the A4000 motherboard out of the case. It's a pain! I have 2 though, so I can experiment with my 'lesser' one.

Don't you have to take it out anyway?

[SnkBitten]

Originally Posted by Jope

Please don't erase EPROMs for 50 minutes.. They can be over erased and will no longer hold data. Only apply UV radiation until it's empty. I tend to blank check mine every 5 minutes, but 15 mins is probably still safe.

I had tried 10 minutes and while they pass "Blank check" in the programmer they refused to write. Reading the mcumull forums many had "erased" theirs for around an hour and were then able to write. I didn't care if I burned out those, I just wanted to see if I would have similar results as those who did erase theirs for an hour. Since 10 minutes, 50 minutes and out of the package all had the same identical results across 10 chips (some erased 10, some erased 50 and some none) I'm leaning more towards hardware vs. something I misconfigured.

[Jope]

Sometime those old chips are dead and you can't write successfully. :-) Those willem clones are especially finicky with UV EPROMs sometimes.

[nogginthenog]

I seem to be having varied success. Sometimes it works, sometimes not. I'm not sure if it's bad EPROMs yet or a dodgy connection somewhere. I tried erasing a non-working EPROM for 30 mins with no luck. Gonna try some more on this one.

One thing I have never worked out: An A4000 uses 2x256Kb ROMs (odd and even) to get a total of 512Kb. But 27C400 EPROMs are 4 megabits, which is 512Kb per ROM!

[SnkBitten]

Originally Posted by nogginthenog

I seem to be having varied success. Sometimes it works, sometimes not. I'm not sure if it's bad EPROMs yet or a dodgy connection somewhere. I tried erasing a non-working EPROM for 30 mins with no luck. Gonna try some more on this one.

One thing I have never worked out: An A4000 uses 2x256Kb ROMs (odd and even) to get a total of 512Kb. But 27C400 EPROMs are 4 megabits, which is 512Kb per ROM!

You have to double the data on each split (hi and lo) sections before burning them so that they fill the entire 512KB.

[nogginthenog]

Just erased a chip for 1 hour. Programmed successfully. This one failed 2 times before. First from new, and this morning with a 30 minute erase. I'm not sure the problem is the erasing time but it could be.

I'm using the cheap Chinese programmer that is everywhere:


BTW, I wouldn't leave this unsupervised. The mains leads (had to put a UK plug on it) are far too thin in my opinion.

[nogginthenog]

Originally Posted by SnkBitten

You have to double the data on each split (hi and lo) sections before burning them so that they fill the entire 512KB.

I understand that but why not use 256K 27C200 (if there is even such a thing). Are A4000 Kickstart ROMs (i.e. the real ones) 256K or 512K?

BTW, is anyone using romtool to build ROMs instead of Remus? This looks like a much nicer option to me. It works with the regular ROM modules but not BlizKick modules. For example, when I add MoveVBR the ROM size decreases but the module is not included. Interestingly the KeymapGB module I made in Remus works OK. I guess I should contact the author (Python is not my thing).

Sorry for the dumb questions! The last time I did anything like this was programming a PAL (or GAL?) in college 20 years ago.

[idrougge]

By all means, use 27C200 EPROMs instead.

[dJOS]

Originally Posted by Jope

Sometime those old chips are dead and you can't write successfully. :-) Those willem clones are especially finicky with UV EPROMs sometimes.

I buy my eproms from a Hong Kong eBay seller, their service is exceptional, in the few times I've had a faulty eprom or two, they've just sent me an entire new batch (I usually buy lot's of 10)!

http://www.ebay.com.au/sch/ic.touch/...1&_ipg=&_from=

[dJOS]

Originally Posted by nogginthenog

Just erased a chip for 1 hour. Programmed successfully. This one failed 2 times before. First from new, and this morning with a 30 minute erase. I'm not sure the problem is the erasing time but it could be.

I'm using the cheap Chinese programmer that is everywhere:


BTW, I wouldn't leave this unsupervised. The mains leads (had to put a UK plug on it) are far too thin in my opinion.

I have one of those too, the chips on the outside of the tray dont get very good coverage so i only place my chips in the centre 2/3rds of the tray.

Btw 30 mins is too long, you'll kill the chips in the centre of the eraser.

[nogginthenog]

Originally Posted by dJOS

I have one of those too, the chips on the outside of the tray dont get very good coverage so i only place my chips in the centre 2/3rds of the tray.

Good point! This could explain why I am getting inconsistent results.

[xArtx]

I don’t know what could happen in a photograph,
but that looks more like the wavelength of a UV inspection lamp than anything else.
Which is just great because I also have that eraser on the way!

It must be a lot smaller than it looks.
Is that a metal enclosure with no earth?

[nogginthenog]

It looks metal but is actually plastic. Mine came with a foreign plug so I put a UK one on (works with 240v OK).

[idrougge]

Do you really have 240 V in the UK?

[dJOS]

Originally Posted by idrougge

Do you really have 240 V in the UK?

And here in Australia and Hong Kong and most of Europe too (it's frequently 220v- 240v).

[idrougge]

That's what I was wondering. I thought all of EU was normalised to 230 V a few years back.

[nogginthenog]

You're right, the UK used to use 240v but in the mid 90s normalised to 230v to match europe. Sorry, old habits. Having said that, my recently purchased set top box says 100-240v :-)