24 Jun
2013
24 Jun
'13
3:17 p.m.
On Mon, Jun 24, 2013 at 5:36 PM, Jim Brain <brain at jbrain.com> wrote:
In practice, no one uses the 9VAC on the 64 and VIC as
AC. It's not on all
user ports, so systems don't plan on it being there...
What about as a source of negative voltage for the RS232 cartridge?
I haven't seen a schematic of it lately, but IIRC, it uses a 1488 and 1489
and needs a bipolar supply and I don't _think_ it has an on-board negative
supply fed by a charge pump.
Obviously it's easy to make new one with a MAX232, but I do happen to
have an original interface, so that's why I thought of it.
-ethan