Path: utzoo!attcan!uunet!lll-winken!lll-tis!mordor!lll-lcc!ames!mailrus!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!ssc-vax!wanttaja
From: wanttaja@ssc-vax.UUCP (Ronald J Wanttaja)
Newsgroups: comp.sys.cbm
Subject: Re:  PLUS/4 Questions
Keywords: PLUS/4 RS232, etc.
Message-ID: <2097@ssc-vax.UUCP>
Date: 15 Jul 88 05:44:13 GMT
Organization: Boeing Aerospace Corp., Seattle WA
Lines: 63

(I tried to mail this, and couldn't get through)

>A couple of questions on the ill fated plus/4:

>   1> What are the registers (what do they do) for the 6551 ACIA chip?
>     I am trying to write a terminal program to take advantage of the
>     plus/4's serial speed (>2400 baud).

COMMODORE MICROCOMPUTING had a PLUS/4 memory map in Nov/Dec 1984.  Here's a
quote from the section on the RS-232:

UOUTQ   $07CD  User Character to send
UOUTFG  $07CE  0=empty; 1=full
SOUTQ   $07CF  System Character to send
SOUNFG  $07D0  0=empty; 1=full
INQFPT  $07D1  Pointer to front of input queue
INQRPT  $07D2  Pointer to rear of input queue
INQCNT  $07D3  # of chars in input queue
ASTAT   $07D4  Temp status for ACIA
AINTMP  $07D5  Temp for input routine
ALSTOP  $07D6  FLG for local pause
ARSTOP  $07D7  FLGfor remote pause
APRES   $07D8  FLG to indicate presence of ACIA

and, in case you need them:

SAREG  $07F2   A register
SXREG  $07F3   X Register
XYREG  $07F4   Y Register
SPREG  $07F5

>    2> Where can I get a programmers reference manual for the plus/4?
>     This manual would keep me from programming in the dark.

Can't help you there.  Never saw one; instead got copies of all the
magazines with PLUS/4 or C-16 articles.  In addition to  the one mentioned
above, there's TRANSACTOR Vol 5 Issue 4 and RUN Nov, 1984.  I used a C-64
to write assmbler for the PLUS/4..  worked pretty good, even for graphics.

>    3> Is there any software available for the plus/4?

Ahem.  Academy Software, P.O. Box 9403, San Rafael CA, 94912, had carried a
PLUS4/C-16 version of IFR, an instruments-only flight simulator, written by
yours truly.  They might still carry it. 


                                q*p
      ___________________________T____________________________
            |    	      |/(_)\|                 |    
            |         -------:**^^^**:-------         |
            |               ((   o   ))               |
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                          TT/_________\TT      Ron Wanttaja 
			  ||           ||      (ssc-vax!wanttaja)




Any and all information is and will be appreciated....

      -Jon

      kenneke@jacobs.cs.orst.edu