IBM 5150 maximum memory?

[Fred Cisin]

On Sat, 26 Apr 2008, Chuck Guzis wrote:
> Yes, they did, but the fans were rated for 50-60 Hz operation and
> impedance-protected.   With the factory, what 62-watt?, PSU, I don't
> think it was possible to stuff the thing full enough of drives and
> cards to make it overheat (remember too, that there were only 5
> slots) to make it overheat.  Wasn't the (black) PSU on the original
> PC fitted with red tamper-telltales stuck on along the edge of the
> PSU clamshell?  I can't remember exactly, but I think it was.

63.5? W
Mine didn't.  Just tamper-proof torx with a black PS case and white
switch.

> As this was an IBM product, I fully expected that there would have been
> some provision for changing the AC input voltage.  Certainly other
> personal computers of the time had the feature, and this wasn't supposed
> to be a product from "Fred's Personal Computer and Aluminum Storm Door
> Company".  One expected a high level of engineering from IBM.

Harrumph.  We don't even have storm doors around here.  It's a matter of
making screen doors, or expanding into other markets.

> I never understood the design that featured a complete lack of a
> clear airpath between the plug-in-cards.  They must not have been
> expecting very much expansion.

They thought that cassette BASIC would remain a popular configuration.

> All in all, for as long as the 5150 was in the rumor mill, one would
> have expected a better thought-through design from IBM.

An awful lot of the rumors were based on, "well, of course it will
be . . .",  "only a moron would make a machine that isn't CP/M"
"Only a moron would make it not be Apple compatible", . . .
"How can it NOT have a 68000?"
Only somebody who doesn't know IBM could make predictions like those.