Scor­pio News


July–September 1987 – Volume 1. Issue 3.

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grown by about 1000H-1500H bytes in length, these extra sectors have to be loaded from the Disk. It is necessary to adjust the sector counter. In my Winchester Boot Loader it is located at 093AH in the system image, and at 0909H in the Floppy loader. The value was 13H in both cases. It will need to be increased. The value of 01CH will load s system configured as shown in Pig. 2. Too large a value will load a system over the top of RAM, crashing the Load process. Too small a value will read insufficient date from the disk.

The debug program can now be exited, and the new system saved – SAVE 66 FULLZ3.SYS. This will save all of the TPA from 0100H to 4300H. It only remains to write this to the Winchester. Note that the bytes from 0100H to 08FFH in the system image file are discarded by SYSGEN and SYSWIN. The actual write starts at 0900H. These bytes MUST be save in the system image file however, in order that the required data starts at 0900H.

The utility SYSWIN.COM is used to write a system to a Winchester, but the other remaining problem now becomes apparent. SYSWIN is set to write a normal sized syetem. The sector counter must again be altered. It is necessary to write all of the much larger system to the Winnie and the Cold Boot Loader sector must be written as well. In my version of SYSWIN this count (at 050FH) was 013H, and I have set it to 01DH.

N.B. I have found that SYSWIN will not work correctly if run from the Winnie itself, or if the system image file is on the Winnie - probably due to hard coded disk drivers. I use both these files from a floppy.

There is another way to get the system written to the Winnie. SYSGEN will carry out a part of the process, but fails part way along – I can’t remember where. If you are really masochistic, you can use the scratchpad feature of SPZ to write 128 byte chunks of your FULLZ3.SYS file to the Winnie system tracks.

For the system to boot correctly from the Winnie on reset or startup, SIMON 4 is needed. (Other Versions may be O.K.) or the utility BOOT.COM can be used. These are not PD programs. Your friendly Gemini dealer should be able to supply you with SIMOM4, BOOT.COM and SYSWIN.COM, unless Gemini have become as difficult about System Utilities as they have about source code. They might insist on you buying or upgrading to BIOS 3.x.

If Gemini intend to continue supporting 80-BUS products (as they say they intend to do), then it is in their interests to serve their customers requirements. If they intend to let these products lapse, then they have nothing to loose in supplying existing users with the programs and information. Either way I think their attitude is wrong - riding my hobby horse again !!

If the Z3 area from 03500H to 04300H only is needed, in order to load as a complete ‘SEGMENT.BIT’ so as to avoid BIOS mods. as described above, it is suggested that a debug program is run, but without loading a system image. (e.g. run DDT or ZSID if .HEX files are to be processed). Memory from 100H to about 05000H should be first filled with 00’s. The segment parts can then be read in at 3500H, etc; as described above. The default startup command can be set as described above. Wheel and Path could be defined in the spare space in the TCAP of the SYS.ENV segment.

Then the required data area can be moved to 100H – M3500,4300,100. This will move a block 0E00 long down to 100H. Exit from the debug program and 13 pages saved – SAVE 13 SEGMENT.BIT. This file can then be loaded to 0F200H by any appropriate means to furnish Z3 with its requirements. Note that LDR.COM cannot load this file, but a CCPZ GET command could be used as already suggested. (Or maybe LDR.COM modified via the .MAC file so as to be able to load it).

ZCPR3 Utility Installation.

The installation of the Z3 utilities is straightforward. It is necessary to carry out three steps.

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