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EEPROM Burner

I have a TL866 too. Works perfectly and is yours for 35 bucks if you search a little.

Do you think your first iteration of the software will already be good? If you have the burner you can make changes.
 
I've been using SST 27SF512's on lh2.4/ezk116 just fine. Just make sure to set the burn offset to 8000
 
Both LH2.4 ECUs and chippable EZKs use a 27C256 EPROM. The EPROMs have a window in the center so that they can be erased with a special UV light. Most are shipped pre-erased, so you don't need to buy a UV eraser immediately. See jameco link.

I'm not sure what speed grade EPROMs were used by LH/EZK. I'd guess 150ns (shown as a -15 or -150 suffix on the part number). On Ebay, search for "TMS27C256-15" or just "27C256". I'd stay away from other speed grades (-20 -25 are too slow, -7 is faster but might cause extra electrical noise).

esmth's great suggestion uses an electrically erasable replacement for the original UV proms. These parts are automatically erased by the PROM programmer as part of the reprogramming (no UV eraser needed).

You should also be able to find "SST 27SF256" parts on ebay that won't need the 0x8000 offset during programming. (Note: there are lots of other brands of 32Kx8 flash proms available, but most are not pin compatible.)
 
28 pin DIP 27c256 DIP the DIP is the important DIP of the DIP chip.

If you wanna get real technical volvo put better grade chips in the puters you know ones that work better at lower and higher temperatures. I wouldn't worry about that and also who here has programmed up a chip and it wasn't fast enough? Too slow of a chip? I call BS on that..

Also I wouldn't use electrically erasable chips in my DIP's configuration of chips. You forgot write once chips, why not use those?

Other then everybody has there own opinion on everything, yeah burn some chips, it's easy.
 
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Sjeng said:
I have bought chips which are "fake SST" according to some people. Never any problems with them.
Click to expand...

i've been told a lot of them are OTP. If you burner has an identification function you can usually see what they really are
 
Interesting to see that there's a problem with counterfeit SST chips. Over the weekend, I ordered 10 of the 27SF256 chips off ebay for $10 total. I'll post a followup once I get them and read out the ID codes (probably 4-6 weeks from China). It looks like Moates.net has genuine 27SF512 chips for $5 each.

As far as the design and speed grade goes, it's all a question of tolerance stackups -- if you have slow processor/latch/prom chips in a hot environment, it may be a bit flakey with slower speed grade proms. Most likely, it will be fine, but why not spend the extra $0.50 to be sure?

[I was thinking back and it's been just under 30 years ago that I did my last board design using UV EPROMs. Everything after that was all electrically erasable and programmable in place -- so much nicer to work with and to support in the field.]
 
I got my 10 for $10 china ebay chips in the mail today. They appear to be genuine SST27SF256 chips -- the device ID is correct, and I can erase them with my old EasyPro 90B programmer but I was unable to program more than one byte at a time. Overall, it's a fail.

I suspect my programmer and not the chips. I did find a newer version of the programmer software but support for the SST27SF256 chips had been removed, which is why I suspect the programmer.
 
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Nope, I can erase it fine. I can program one byte to whatever I want just fine, erase it again, program something different, but just the one byte. I can do this with any one byte in the 32KB range so I'm guessing the programming algorithm is too fast and fails on the 2nd byte.
 
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