[sdiy] Nasty Bits in EPROM

[Colin Fraser]

> -----Original Message-----
> From: owner-synth-diy at node12b53.a2000.nl
> [mailto:owner-synth-diy at node12b53.a2000.nl]On Behalf Of Rob
> Sent: 19 April 2001 13:06
> To: Synth-DIY list
> Subject: [sdiy] Nasty Bits in EPROM
>
> Anyone ever have a UV EPROM that just will NOT erase
> completely? I always
> seem to have a bit that says FB, but its not at the same
> address every time.
> I dled the rom image and did a search, and I find FB in 2-3
> places, but
> after UVing them, the addresses change!!

Most likely a bad ROM. I've had exactly the same failure in other devices.
I suppose it could be a fault in the programmer.
I would check (if possible) that the behaves the same on another one.

I had a problem with EPROMs getting scrambled a while back that turned out
to be a bug in a Hex to Binary conversion utility.
Of course I had ripped the hardware apart and checked every last thing
before I thought to check the bin files directly...


Colin f