29 Jul
2013
29 Jul
'13
9:22 p.m.
On Jul 29, 2013, at 5:29 PM, Eric Smith wrote:
The PC Jr DMA restriction wasn't a problem with
the serial port,
either, since normal PC serial ports don't use DMA. On a typical PC of
that time, DMA was only used by the disk controllers. It was added
for other things like sound cards around 1989 and ECP parallel ports
around 1992. Of course, there were other cards that used DMA, just
nothing very common.
I guess I should clarify... the serial port by itself isn't affected by the DMA,
however doing reliable file transfers over the serial port to disk does.