tezza
Veteran Member
hmm..ok, first hitch.
The 76c16Q (edit: no, ignore that. I mean 27C16Q) chips arrived today. These were all used except two. I figured I'll see if I could get the binary in one of them for my Sorcerer BASIC ROM-PAC.
First problem I ran into was figuring what programming voltage to use. The Willem docs under EPROMS say "...As an example: write a 27C16 (programming voltage is 12.5V), also you need change the Vcc voltage setting accordingly..."
Hmm...the other docs I have (datasheets) suggest 25 volts for programming. So now I'm confused. Anyway, I tried what the manual said and used 12.5 V. No joy, no writing took place. So I tried again this time using 25V. Joy! Programming DID take place...but....uh oh, the very first byte was wrong. A zero whereas it should have been a 32. All the other bytes were correct and accounted for.
I figured maybe the first attempt at the low voltage might have done something to that first byte initially. So, I tried again at 25v with my second blank 27C16.
Same result. Ok, except for that very first byte?
Anyone got any ideas? There is a slider setting called tWP (default 140.0 us) and another called tWC (default 20.0 us) which may relate to programing pulse speed delay? The manual doesn't actually say what these do but they can be altered. Should I bump them up? The input voltage is 12V DC BTW, supplied from a power pack.
The pdf manuals are actually very bad. First there are FOUR versions with conflicting information none seem to match the hardware absolutely.
Oh well, no harm done. I have 14 26C16s but those were the only two blank ones. However, I'll have to wait for my eraser to arrive from Hong Kong before I can do anything else. Meanwhile, if anyone has any ideas, I'm all ears.
Tez
The 76c16Q (edit: no, ignore that. I mean 27C16Q) chips arrived today. These were all used except two. I figured I'll see if I could get the binary in one of them for my Sorcerer BASIC ROM-PAC.
First problem I ran into was figuring what programming voltage to use. The Willem docs under EPROMS say "...As an example: write a 27C16 (programming voltage is 12.5V), also you need change the Vcc voltage setting accordingly..."
Hmm...the other docs I have (datasheets) suggest 25 volts for programming. So now I'm confused. Anyway, I tried what the manual said and used 12.5 V. No joy, no writing took place. So I tried again this time using 25V. Joy! Programming DID take place...but....uh oh, the very first byte was wrong. A zero whereas it should have been a 32. All the other bytes were correct and accounted for.
I figured maybe the first attempt at the low voltage might have done something to that first byte initially. So, I tried again at 25v with my second blank 27C16.
Same result. Ok, except for that very first byte?
Anyone got any ideas? There is a slider setting called tWP (default 140.0 us) and another called tWC (default 20.0 us) which may relate to programing pulse speed delay? The manual doesn't actually say what these do but they can be altered. Should I bump them up? The input voltage is 12V DC BTW, supplied from a power pack.
The pdf manuals are actually very bad. First there are FOUR versions with conflicting information none seem to match the hardware absolutely.
Oh well, no harm done. I have 14 26C16s but those were the only two blank ones. However, I'll have to wait for my eraser to arrive from Hong Kong before I can do anything else. Meanwhile, if anyone has any ideas, I'm all ears.
Tez
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