README_BOOTSYS

    My english is not so good, I hope you understand what I write here.
    ---
    See also yaze-ag.doc chapter "4. Some words to BOOTSYS"
    ---

    What is BOOTSYS?
    ================

    The BOOTSYS utility relocates and places the resident and banked (if present)
    part in CPM3.SYS to their right places into memory and starts CP/M 3.1.

    BOOTSYS WILL NOT WORK ON ALL CP/M 3.1 SYSTEMS. Why?
    If the MOVE & XMOVE routines are placed in the banked part of the BIOS then it
    is possible that this routines can be overwritten when bootsys+cpm3.sys are
    transferred from bank 1 (TPA) to bank 0 (SYS).

    Try it. If this utility works under your CP/M 3 system then you can start
    a new version of your BIOS3 from the current one without having to write
    it to the system tracks!

    What does BOOTSYS:
    ==================

    	1. Check if CP/M vectors are present at 0000H (wboot) and 0005H (bdos).

    	   - If present all output go direct to the conout of the bios. So
    	     this utility works also with other CP/M 3.1 systems than YAZE-AG.
    	     (Try it, I want to know if bootsys works on your cp/m-3-system.)

    	   - If not, bootsys try to boot CPM3.SYS using YAZE-AG.

    	2. If CP/M vectors are present it checks if a Drive (e.g. 'p:') is
    	   given as a parameter to the bootsys call:

    	   - If present bootsys tries to load CPM3.SYS from that drive.

    	   - if not present bootsys tries to load CPM3.SYS from the default
    	     drive which is defined in the source of bootsys.mac.

    	3. Test if a copyright message is in the loaded/joined CPM3.SYS.

    	   - If not a message will be printed and bootsys exits.

    	4. Test if CP/M 2.2 or CP/M 3.1 is running (only if cp/m vectors are
               present):
    		CP/M 2.2 --> boot CPM3.SYS at once.
    		CP/M 3.1 --> transfere all from bank 1 (TPA) to bank 0 (SYS)
    			     switch to bank 0 and boot CPM3.SYS.
    			     (If your Bios does not support xmove bootsys
    			      prints a message and exits.)

    	5. Relocate CPM3.SYS   (look to bootsys.mac on drive P: how I
    				do it. The comments are in german and
    				english language ;-))

    	6. Start CP/M 3.1 by jumping into the boot routine of the bios3.

    How do you use BOOTSYS?
    =======================

    You have two ways to use BOOTSYS.COM:

    1. Call BOOTSYS.COM in your CP/M 3.1/2.2 system. You can give a parameter
       for a drive (e.g. "p:" (the colon is necessary)) or not. If there is a drive
       given BOOTSYS tries to load CPM3.SYS from that drive which is given in the
       parameter.
       If there is no drive given BOOTSYS.COM tries to load from that drive which
       is given in the source BOOTSYS.MAC (e.g. 'A').

    2. You generate a CPM3.COM for starting CP/M 3.1 with the following command:

    	PIP CPM3.COM=BOOTSYS.COM,CPM3.SYS

       You simple append CPM3.SYS to BOOTSYS.COM and save both in CPM3.COM.
       Then Call CPM3.COM to start CP/M 3.1. Bootsys starts the attached CPM3.SYS
       at once.

    CPM3.COM is identically with the boot file "yaze-cpm3.boot" which is loaded at
    the start of yaze-ag and is places in /usr/local/lib/yaze/yaze-cpm3.boot .

    February 14, 2022
    Dipl.-Ing. (FH) Andreas Gerlich
    (University of Ulm, Germany)

    only text emails please: address removed !!!