Help with getting an original Altai running: 8080A clock circuitry and MITS88 2-SIO board

[drlegendre .]

Good point.. and if you have the later PSU with the 95,000uF 12V cap, pay
close attention to that guy.

FYI, power supplies in the Altair typically work like this: In the chassis,
there are two regulated +18 / -18V supplies of 1A each, and an unregulated
~8V supply capable of substantial current. On the individual boards, the 8V
supply is commonly regulated down to 5V (with 7805, etc.) and when needed,
the +/-18V supplies to +12V / -12V with simple zener diode shunt circuits.

On Sun, Feb 7, 2016 at 4:43 PM, Eric Smith <spacewar at gmail.com> wrote:

> On Sun, Feb 7, 2016 at 3:23 PM, Kip Koon <computerdoc at sc.rr.com> wrote:
> > I also have an original Altair 8800 that has not been powered up since I
> was
> > in my late teens or early twenties.  I'm 56 now and I was wondering if
> > anyone has put together a document for successfully restoring Altair
> > computers specifically and retro style computers in general.
>
> IMPORTANT: Do NOT power up until you've tested the DC power supplies
> *without* the boards installed. Check DC voltages and ripple. Aluminum
> electrolytic filter capacitors may need to be reformed or replaced.
> (But let's not restart the argument about which to do!)
>