Old MOS Mask-Programmed ROM forgetfulness?

John Robertson jrr at flippers.com
Tue Feb 16 15:50:53 CST 2016

On 02/16/2016 12:43 PM, dwight wrote:
> It is interesting, I have 1702As that were programmed in 1973 sometime
> and they still have their data ( used on my SIM4-01 ).
> And yes, I have them backed up.
> It is interesting that Data I/O has added supply current
> checks. I've used many home made pin adapters over the
> years to read old ROMs, as John probably knows, as some
> were from pin ball machines.
> Some of the earlier ROM also had address latches built in,
> making reading tough.
> Anyway, making pin adapters is not that hard. I usually stack
> a three solder pin, machine pin sockets.
> In place I don't want any connection, like Vpp, I pop the pin
> out. In other places where I need to rewire, I break the
> solder pin off and file it down a little so it won't short.
> I do connections and sometimes vector side boards with
> soldered wire wrap wire. Often I need switches or sometimes
> logic off to the side.
> It only takes 15 or so minute to put a typical adapter
> together.
> Dwight

And one could use a 9-Volt battery for the -9 on one of these home-made 

John :-#)#

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