On 3/3/2012 7:19 AM, Christian Corti wrote:
On Fri, 2 Mar 2012, Al Kossow wrote:
Providing detailed information on this would be
helpful in the future
if someone needed to build a non-mechanical replacement for the drum.
What else do you need besides the service manual that contains all
details and schematics? There are timing diagrams of the timing tracks
along with all logic equations that are used to derive the individual
parts from the read signals (e.g. sign bit, address part, opcode part).
I know of at least one Bendix G-15 that could
probably be checked out
if a replacement for the drum could be put together.
What exactly is the problem? From a first look at the G-15 docs, there
seem to be all required details of the drum and timing tracks.
reference manuals and documentation have a nasty habit of being less
useful than an actual account of all of the procedures used by one who
actually performed some deed.
I would love to know what steps were used to read off a drum, if the
unit had to be functional to operate the drum, what was modified, how
was the drum spun up, what external circuitry was used to obtain the
data. I think there is one LGP-30 drum in our posession and two
LGP-30's, one functional, one maybe not so which all have drums.
Before I'd embark on the task I'd love a detailed explanation of what
you or your group did to do retrieve the data and store it, passively or
if you had to restore things, what and how.
There have been accounts here recently by people detailing what they did
in detail which would be helpful for the restorers of such hardware, and
that you digitized your drum is very interesting.
The construction of a replacement would be aided in the insight gained
in interfacing to the existing drum.
Christian