On 2015-01-14 17:40, James Knott wrote:
On 01/14/2015 09:48 AM, Yamaban wrote:
RS232 was original defined as polling with hardware buffers only. During the later days of the ISA bus (ISA 32bit IIRC) there where cards available the generated a IRQ if new data arrived at the buffers.
That was the case with DOS, which had very poor com port support.
The operating system itself was very basic, true. But applications commonly supported themselves whatever they needed that the OS did not, like printer driver, graphic drivers, sound, etc. Interrupt hardware was handled the same way, by the application, or by a TSR. I wrote one myself, using sample code that came with Turbo Pascal from Borland, so it was not that difficult. (By the way, SUSE is cousin to Borland, in a way. Same owner ;-) ) -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)