30 Sep
2011
30 Sep
'11
1:29 p.m.
On 30 Sep 2011 at 20:16, Tony Duell wrote:
Not so. The problem is the power and ground pins. Not
many (if any)
microcontrolelrs can source/sink the current for some of the older
EPROMs. And AFAIK none can output +12V or -5V levels which are needed
if you want to be able to read 2708s and the 3-rail 2716s (that was a
design requirement of my unit, I wanted to back up the firmware in a
old Sanders dot matrix printer).
I was still thinking about reading PAL/HAL/bipolar ROM in 0.300" wide
DIP sockets. I'm not aware of a PAL with center-fed power, are you?
As far as power for EPROMs and the like, that could be handled pretty
easily, as for most devices, it's Vcc that moves around a bit. Some
MOSFET driven by a decoder could probably do the job pretty well, as
there aren't that many alternative pins to choose from. (3-rail
devices excepted).
--Chuck