using 87c256

EPROM EEPROM SRAM NVRAM Flash chips, reading/writing hardware and software
Post Reply
kelvin
Posts: 38
Joined: Sat Apr 10, 2010 4:24 pm
cars: Commodore

using 87c256

Post by kelvin »

I have a VN computer with what I assume is a 87c128 eprom. The first memory location appears dead as it always reads as FB, no matter how long I cook it in the eraser, the rest of the buffer shows all FF's. I have a supply of 87c256's. Can I just swap it over and I believe I need to write the bin twice or double it up or something.
vn5000
Posts: 551
Joined: Fri Jul 17, 2009 2:11 pm
cars: vn v8 commodore
Location: GOLD COAST QLD

Re: using 87c256

Post by vn5000 »

Its not 87 its 27c128
kelvin
Posts: 38
Joined: Sat Apr 10, 2010 4:24 pm
cars: Commodore

Re: using 87c256

Post by kelvin »

Sorry, that's what happens when you start typing before engaging your brain.
vn5000
Posts: 551
Joined: Fri Jul 17, 2009 2:11 pm
cars: vn v8 commodore
Location: GOLD COAST QLD

Re: using 87c256

Post by vn5000 »

Yeah just stack the bins 0000 -3fff 4000 - 7fff
kelvin
Posts: 38
Joined: Sat Apr 10, 2010 4:24 pm
cars: Commodore

Re: using 87c256

Post by kelvin »

Thanks, I'll give it a go.
User avatar
VL400
Posts: 4991
Joined: Sun Mar 01, 2009 2:54 pm
cars: VL Calais and Toyota Landcruiser. Plus some toys :)
Location: Perth, WA
Contact:

Re: using 87c256

Post by VL400 »

Or if your programmer supports it just load it once starting at 4000 - The ECU will never address the 0-3FFF area of the EPROM so its not required unless you want to have switchable maps.
Post Reply