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22RSX
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BYERSX.ARK
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RSXBYE.DOC
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Text File
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1985-11-27
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5KB
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104 lines
; Some program notes for RSXMAIN.BYE.
;
; Name this file BYERSX.INC for inclusion in an assembly listing.
;
; The RSX has available to it the routines from RSXMAST
; TSTR (like DOS string call, but registers preserved)
; DOS (like BDOS call, but register A specifies the function,
; and the bc, de and hl registers are preserved)
; GOBDOS (Just like the original BDOS call).
; note that DOS and GOBDOS do not use the RSX code.
;
; RSXMAIN.BYE defines a BYE replacement RSX. It is a customization
; of the RSXMAIN.XXX outline. The system is designed so that
; simple programs can replace BYE, XMODEM, MODEM etc. The system
; will be installed and then the appropriate program can be run.
; Rerunning BYERSX will bring down the system (or a BDOS call 57h
; with a parameter 0ffffh can do it programatically).
;
; This system makes no attempt to answer phones, etc, but simply
; provides a suitable environment for other applications. It does,
; however, monitor remote carrier and inactivity. If any of these
; conditions cause call termination, the program ENDCALL will be
; automatically executed. Further operation is entirely up to
; ENDCALL. It is expected to record whatever is needed, and call
; BYE (not the original, but a co-operating application), which
; will perform the call reception and system initiation. The
; chain operation (BDOS call #2fh, chain to command line in
; dmaadr) is available to perform these operations. Note that
; if the e value is 0ffh during a chain, the current logged drive
; and user will be made the default.
;
; All operations are intended to be performed through BDOS calls.
; No external program should need to refer to the load point of
; this module in any way. Pointers and values are returned thru
; the various calls. See documentation of functions available.
;
; The mxdrv value is used, but is replaceable by a bit vector of
; available drives. This vector initially allows all drives, for
; compatibility. Setting the mxdrv to 15, and using the vector,
; provides precise control, especially useful when "holes" in the
; drive map exist (for example an M drive).
;
; Acknowledgement: This system draws heavily on the features and
; function of BYE334 through 339.
;
; DO NOT MAKE A SEPARATE dseg. When this system is executing is
; is either as the result of a BDOS call, on the user stack, which
; is switched on entry, or as a bios replacement, when the BDOS
; stack may be in effect. Any operations that may originate from
; BDOS cannot use BDOS itself, unless they are aborts, which will
; never return to BDOS, and switch stacks.
;
; Copyright (c) 1985 by
; C.B. Falconer, 680 Hartford Tpk.,
; Hamden, Conn. 06517 (203) 281-1438
; all rights reserved.
;
; This program may be freely used and copied for non-profit purposes.
; It may not be sold without the express permission of C.B. Falconer.
;
; Note: peak stack use occurs with function keys, and is mainly
; aggravated by the bios call register protection. If the bios can
; be trusted not to disturb registers other than a and f, this
; use can be reduced.
;
; Note: debugging is simplified by:
; 1. Mount rsx with "byersx"
; 2. Dismount with "enquire 57 ffff"
; 3. Load DDT with "ddt"
; at this point the RSX code is still in protected memory, but has
; been disconnected from BDOS/BIOS. DDT can load and execute test
; programs (but set up your own stack area). The ^C which exits
; DDT will remove BYERSX from memory, and reset the protection.
;
; Note: Mysterious crashes can result from excessive stack use. The
; normal BDOS stack of 48 bytes handles this. If interrupts are
; occurring or if the bios proper uses too much stack this may not
; be adequate. For CPM 2.2 the entry point at BDOS+11h shortly
; loads SP, and you should examine usage under DDT while exercising
; the functions. The heavy usage can be eliminated by removing
; the function key abilities.
;
; Some systatus values of interest, and meanings:
; Binary Hex Meaning
; xxx00000 0 Normal system operation. Default condition.
; xxx00100 4 Remote console, showing on local. Hard wired remote.
; xxx10100 14 Remote console, showing, via modem. Carrier checked.
;
; Modes with local kbd/screen functioning as a terminal. Conoff set.
; With conoff set any executing programs are paused. No disk access.
; xxx01100 c Operating as console on remote cpu that echoes
; xxx01110 e Half duplex, operating as console.
; xxx01101 d Conversation with remote console.
;
; --------------------------------
;
; This file may be used to include data areas compatible with
; the existing BYE programs. A BYE replacement must always
; have "driver" set true, and "nodrive" set false. When code
; is included here it will cause the replacement bios jump
; vector to be located higher than usual, which may cause
; problems with some programs that are careless in calling
; the bios directly. For most RSXs this file contains no code.
°¢