Offsets when burning different EPROMS

EPROM EEPROM SRAM NVRAM Flash chips, reading/writing hardware and software
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Re: Offsets when burning different EPROMS

Postby j_ds_au » Mon Nov 09, 2020 8:46 pm

vlad01 wrote:The higher the capacity the eprom the longer it takes to clear under UV as the cells have a physically smaller surface area for exposure.

No, I don't think so. The cells are smaller but they hold less charge. Only programming takes longer, because unlike erasure, it's done one byte at a time.

Joe.

PS. Double-checked the datasheets ...
The Intel 2716 datasheet says "The integrated dose (i.e. UV intensity x exposure time) for erasure should be a minimum of 15 Ws/cm2", while the SGS-Thomson 27512 datasheet says "The integrated dose (i.e. UV intensity x exposure time) for erasure should be a minimum of 15 W-sec/cm2". So 2kB to 64kB with identical erasure dosage.

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Re: Offsets when burning different EPROMS

Postby heff0018 » Wed Nov 11, 2020 6:05 am

I’m glad this post was revisited. I didn’t realise there was a problem with offsetting using the GQ-4X burner and no wonder we couldn’t get the burnt chip to work. I will try bin stacking once I get my Ute back running. Engines out while I am repainting the engine bay. Fiddly job that one.

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Re: Offsets when burning different EPROMS

Postby vlad01 » Wed Nov 11, 2020 9:34 am

I got the GQ-4X and have always offset, never stacked. Never had an issue.
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Re: Offsets when burning different EPROMS

Postby antus » Wed Nov 11, 2020 9:50 am

Ive got a GQ-4X which must be nearly or about 10 years old now and it does or did have a problem with offsets. It might depend on firmware version or type of chip. I just dont do offset now because its so easy to fill out the chip space and mostly im writing 11P and 12P base tunes from the same images which are built to chip size anyway. YMMV.
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