[Coco] Bit-Banger Serial as external console?

[Bill Pierce]

Stephen, if you're using hdbdos, then you probably need to use the slowdown poke as hdbdos for Coco3 always runs in double speed. This will double your baud rate. In fact, that's why it was done to start with, to get the baud rate needed for drivewire.
 
 
 
-----Original Message-----
From: Stephen Pereira <stephen.m.pereira.sr at gmail.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Tue, Mar 26, 2019 3:18 pm
Subject: Re: [Coco] Bit-Banger Serial as external console?

Hello again, folks,

I took Arthur’s advice and started looking for BBS code.  I ended up looking at an article in the November 1983 Rainbow titled “Remote Operation of the Color Computer”.  It has exactly what I think I need.  The tiny assembly language program installs input & output from a remote terminal along with the normal keyboard and screen.  When running, a person at the remote terminal can operate the CoCo as if they were directly on the system.

Of course, the trouble is that the program does not work for me on my CoCo 3.  The communication gets established, but the actual characters get scrambled in both directions.  I’ve tried 150, 300 and 600 Baud, as well as 1 or 2 stop bits, and 7 or 8 data bits.

I’m concerned that maybe this code cannot work properly on the CoCo 3 because it had not yet arrived?  

Here’s a copy of the code if anyone else would like to try it out.  Please let me know if you are successful!

********************************
*          REMOTE            *
*  A REMOTE TERMINAL DRIVER  *
*        FOR THE COCO          *
* DAN DOWNARD  RAINBOW  11/83 *
********************************
        ORG    $3F00
* EQUATES FOR ROM & RAM ADDRESSES
IHOOK  EQU    $016A
OHOOK  EQU    $0167
PIA    EQU    $FF22
POLCAT  EQU    $A000
RSOUT  EQU    $BE0C
BAUD    EQU    $E6
BAUDR  EQU    $C9
DEV    EQU    $6F
FLAG    EQU    $70
* INITIALIZE RAM HOOKS
START  LDA    #BAUDR
        STA    <BAUD
        LDX    1+OHOOK
        STX    1+ORET2,PCR
        LDX    1+IHOOK
        STX    1+IRET2,PCR
        LDA    #$7E
        STA    IHOOK
        STA    OHOOK
        LEAX    OUT,PCR
        STX    1+OHOOK
        LEAX    IN,PCR
        STX    1+IHOOK
RET    RTS
* OUTPUT CHARACTER IF DEV=0
* INSERT LINE FEED TO REMOTE DEVICE
* USE ROM SUBROUTINE
OUT    PSHS    A
        TST    <DEV
        BNE    ORET1
        CMPA    #$0D
        BNE    REMOUT
        LDA    #$0A
        JSR    RSOUT
        LDA    #$0D
REMOUT  JSR    RSOUT
ORET1  PULS    A
ORET2  JMP    RET
* INPUT FROM KEYBOARD OR RS-232
* IF DEV=0
* USE RSIN FOR REMOTE INPUT
IN      CLR    <FLAG
        TST    <DEV
        BNE    IRET2
        LEAS    2,S
        PSHS    B,CC,X
IN1    JSR    [POLCAT]
        BEQ    REMIN
        BRA    IRET1
* CHECK FOR REMOTE INPUT
REMIN  LDB    $FF22
        RORB
        BCS    IN1
* RS-232 INPUT ROUTINE
* BYTE INTO A REGISTER
RSIN    BSR    HALF
        LDB    #1
        PSHS    B
        CLRA
RSIN1  BSR    FULL
        LDB    PIA
        RORB
        BCC    RSIN2
        ORA    0,S
RSIN2  ASL    0,S
        BCC    RSIN1
        LEAS    1,S
        ANDA    #$7F
IRET1  PULS    B,CC,X,PC
IRET2  JMP    RET
* BAUD RATE DELAYS
FULL    BSR    HALF
HALF    PSHS    A
        LDA    <BAUD
HALF1  BRN    HALF1
        DECA
        BNE    HALF1
        PULS    PC,A
        END    START
        

smp
- - -
Stephen Pereira
Bedford, NH  03110
KB1SXE


> On Mar 26, 2019, at 2:03 PM, Chester A Patterson <vchester at setec-cr.com> wrote:
> 
> Years ago I used Cocos via their bit-bangers to communicate with remote screens connected to scales in production lines. The scale keyboard had three function keys to communicate back to the Coco. So the scale operator interacted with the Coco all day. I enjoyed those projects immensely.  I got the idea because of reading in Rainbow (I think) of some oil drilling site that used a Coco to control the drilling. Ages ago that.
> 
> -----Original Message-----
> From: Stephen Fischer <SFischer1 at Mindspring.com> 
> Sent: Monday, March 25, 2019 9:47 PM
> To: coco at maltedmedia.com
> Subject: Re: [Coco] Bit-Banger Serial as external console?
> 
> 
> It is out of scope for your project,
> 
> But I remember vaguely using OS-9 to log in on another computer using the bit banger on the CoCo.
> 
> If someone can confirm that, the NitrOS-9 source code might be useful to look at.
> 
> It has been 25 +- 10 or more years so my memory is very fuzzy.
> 
> SHF
> 
> 
> 
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