Scor­pio News


January–March 1988 – Volume 2. Issue 1.

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second key was struck, the system switched to the first screen again and carried out the command.

I have modified the software to enable this. On system cold boot, the embedded command in the Z3 multiple command line buffer is:

SAK;^C for system, saving TPA. Other keys load Help and Menus;​CSET;​SWSCR;​TYPE TKEYS.TXT;​SWSCR;​SETUP

In turn, this allows the user to go direct to the system (in case of reboot of a crashed system where a SAVE is needed), or loads a preferred character set to the SVC, Switches to Screen two, Types the ^T command menu, switches back to screen one, loads a system set-up menu, (SETUP.COM is MENU.COM, renamed and modified to load a file named START.MNU.)

When the user types ^T, code in the BIOS keyboard routine detects this and calls code within the BIOS similar to that in SWSCR.COM to switch screens, thus presenting the user with a more descriptive display of the options available. After the second key control key has been entered, the BIOS switches back to SVC screen one, and processes the command.

Multi-Operating System Data Corruption Problem

Despite my preference for ZCPR3 as a much more powerful and friendly operating system, it is sometimes necessary to use some other system. At work, MAP80 CP/M Plus is available, together with a suite of MAP80 programs that allows reading, writing and formatting of a large number of disk formats including CP/M, BBC, and MSDOS. This suite needs CP/M Plus to run, and so I have a version of CP/M Plus set up that will access the Winchester, as well as several floppy formats. Recently I was asked to transfer a large number of files from a ‘foreign’ CP/M format (ICL) to IBMPC format. Since I could not do this directly between the floppies, I had to read the files on to an unused DU: on the Winchester, and then to load a special MSDOS transfer program to write the files to the MSDOS disks. This exercise was completed without problem. On completion the ICL files were ERAsed from the Winchester.

The ZCPR3 system allows access to USER areas up to 31 inclusive, instead of 15 as with CP/M. The ZCPR3 installation notes suggest that the HLP (system HELP) files are held in USER 16. The HELP.COM file supplied with ZCPR3 will find these files, and by putting them in USER 16 they are out of the way and will not interfere with normal directory displays. Recently I tried to use some of the 500k odd bytes of ZCPR3 .HLP files that reside on the Winchester and I found them

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