2015's calculator anniversary - the SR-52

[jebem]

Thank you for the extra photos of your SR-52A, Etienne!
Nice work of yours.
That FroggySoft information is very useful too. Thanks.

Concerning the card reader motor wheel outer diameter value, I'm not sure about what the correct value must be, because:
- There are several revisions of the SR-52 (A thru L) and at least one SR-52A revision;
- And it seems that there are different versions of the motor body as well (my specimen has a nude metallic body (dimensions published previously), while yours and FroggySoft motors appears to have a sort of plastic cover around the metal body?).

On a very positive note:
I managed to get an original paperback version of the "SR-52 and SR-52A Troubleshooting Guide"!
Among other goodies, it contains specific information on the card reader controller variants and details the adjustment procedure for the photocoupler card sensor and motor speed.

Katie was very kind to host a high resolution (300dpi) digitized copy for easy sharing among us.
Thank you, Katie!