Date   : Mon, 05 Jan 2015 23:31:01 +0000
From   : jgh@... (J.G.Harston)
Subject: Serial console active at power-on

John Kenyon wrote:
> If all you want is something to enable serial and drop you at a BASIC
> prompt, then I'd create a language ROM which configured the serial
> port, and then did an OSCLI with "BASIC" to switch languages.

Even better, create a *service* ROM that configures the serial port, 
then just allows the MOS to continue on to entering BASIC normally 
instead of bombing out of the startup sequence halfway through.

.Service01
TYA:PHA
LDA #7:LDX #baud:JSR OSBYTE
LDA #8:LDX #baud:JSR OSBYTE
LDA #2:LDX #1:JSR OSBYTE
LDA #3:LDX #1:JSR OSBYTE
PLA:TAY
LDX &F4
LDA #1
RTS

Something to be careful about - if your remotely-controlled Beeb issues 
a VDU 14 you will have to somehow manually press the SHIFT key to get 
the display to scroll! It's worth putting an intercept on WRCHV to 
always disable VDU 14.

-- 
J.G.Harston - jgh@...      - mdfs.net/jgh