Re: Apple II Memory Expansion Card

["mdj" <mdj.mdj@gmail.com>]

David Wilson wrote:

> I have a RamFactor in my hands and it has two jumpers joining pins 1-2
> and 3-4 on the 4 pin connector. As two of the pins must be +5V and GND
> I cannot see how either of the other pins could be clocks.

Interesting... It doesn't make a whole lot of sense to deliver two 5V
lines only to simply join them in parallel though. Perhaps the jumpers
are intended to be removed to provide additional injection points, for
example in the case of a 4mb expander on the card?

I don't see why the battery and mains power would be delivered
seperately either. Seems to be the RamCharger would be nothing more
than a power supply trickle charging a 12V sealed lead acid battery
(what else was available in 1985?) plus a simple power supply circuit
delivering 5V via the battery terminals.

Any modern recreation of the device would be best redesigned using
current battery technology in any case. I seem to recall the RamCharger
housing its battery in a large steel box with the power suppy. The
later RamKeeper board for the IIgs that provided similar functionality
used a Gel-Cel that mounted inside the IIgs case and a simpler
plug-pack style power supply. I seem to recall the advertising at the
time touted the newer batter technology as safer, indicating that the
RamFactor battery had to housed externally as it was reasonably likely
to leak over time.

Wasn't there a Slinky card produced by Cir-Tech that used static ram
plus simple power provision to keep it's contents? The Stat-Disk or
something like that ... ?

Matt