Re:Reversing Sinclair's 1974 calculator hack (2013)
by Turing_Machine on Friday September 17, 2021 @07:21AM
(#28564046)
> Sinclair products were almost comical in how ingeniously their engineers shaved off any pennies they could.
Yes, that was their rule from day 1.
My favorite: in the early days, Sinclair designed a very cheap transistor radio -- so cheap that it didn't even have a speaker, just an earphone (mono, one ear). Sinclair noticed that the available earphone jacks had a built-in switch that was intended to disconnect the speaker when the earphone plug was inserted. Since there was no speaker, this switch was repurposed to serve as the on-off switch for the unit -- plug in the earphone and it's on, pull it out and it's off. That saved both the cost of a separate switch and the space it would have taken up.
I believe this hack required manually bending the contacts on the jack switch to turn it from NC to NO.
Yes, that was their rule from day 1.
My favorite: in the early days, Sinclair designed a very cheap transistor radio -- so cheap that it didn't even have a speaker, just an earphone (mono, one ear). Sinclair noticed that the available earphone jacks had a built-in switch that was intended to disconnect the speaker when the earphone plug was inserted. Since there was no speaker, this switch was repurposed to serve as the on-off switch for the unit -- plug in the earphone and it's on, pull it out and it's off. That saved both the cost of a separate switch and the space it would have taken up.
I believe this hack required manually bending the contacts on the jack switch to turn it from NC to NO.