23 Nov
2010
23 Nov
'10
12:16 p.m.
I'm pretty sure that you need to read the ACIA data register at some point
after determining that a character is available else you will not get
updated status for the next incoming character.
On Tuesday (11/23/2010 at 03:32PM +0100), Wim wrote:
Exactly. And I just figured that they all are framing errors. Here's my test
program that should exit when it reads a byte that has no framing error:
LDAA #%00010000 ; like in jbug (8bit, np, 2stop, no divide)
STAA $8008 ; acia control reg
READ LDAA $8008 ; acia status reg
ASRA
BCC READ ; branch unless data ready
LDAB $8009 ; maybe? read the
incoming byte, arm for next
BITA #%00001000 ; check framing error
BNE READ ; branch if framing error
SWI
Chris
--
Chris Elmquist