25 Jun
2005
25 Jun
'05
8:42 p.m.
From: "lee davison" <leeedavison at yahoo.co.uk>
Sent: Saturday, June 25, 2005 6:49 PM
The 2708 can be programmed non-sequentially and the pulse can either be one
50ms or multiple shorter pulses that adds up to 50ms. There are other
"fast" techniques where you write with a short pulse, read and rewrite until
all cells verify then run one more short pulse write.
Randy
www.s100-manuals.com
> What
programmer can I look for that has the ability to program a
> 2708?
I have a Softy 2 that can do it if you're really stuck.
Not just that, the programming algorithm is
different to most
other EPROMs. IIRC you have to program all locations in sequence,
giving each one a 1ms (IIRC) programming pulse, and repeat that
50 times.
Any bit in any byte can be individually programmed from 1 to 0.
There are no sequence requirements, the programming pulse is one
pulse of 50ms per location programmed.
You can't program odd locations like you can
in later EPROMs.
You can, it's EPROM microcontrollers like the 68705 that need to
be programmed in sequence.
Lee.