Model 40 Re: IBM 360 Model 50 information?

Jon Elson elson at
Tue Apr 2 10:20:42 CDT 2019

On 04/02/2019 09:49 AM, Al Kossow via cctalk wrote:
> On 4/1/19 7:45 PM, Bill Degnan via cctalk wrote:
>> can you show me an example?  Long shot but I can at least check to see if I
>> have any in my 360 docs.  I have mostly programming manuals and general
>> hardware docs but a stray ALD may be present.
> ALDs are 11x17, and are marked with the product number on the spine of the n-ring binder
Not only that, they are marked with the machine serial 
number, and are specific to that machine.
So, any ECOs, or hardware options present in that machine 
will be shown on the schematics.
There will be several other manuals in the set that are not 
specifically "ALD"s, but are part of the set, such as 
microcode listings and FLT (Fault Location Test) manuals 
that reflect ECOs and options.


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