APPENDIX EIGHTEEN _________________________________________________________



Changing The 400/800 OS On The
XL/XE Computers
When you boot the Translator disk, use one of the commercial "fix"
disks (such as FIXXL), or run Matt Ratcliff's "ROM OS to RAM OS" pro-
gram (Appendix 19), you turn your OS from ROM based to RAM
based. This allows you to change it by POKEing directly into mem-
ory. When you use the Translator or the Allen MacroWare XL BOSS
chip, you have the 400/800 operating system in memory instead of
the XL/XE OS.

This section describes many changes which can be made to the
400/800 OS when in the XL/XE RAM. In all cases, Revision B OS is de-
scribed since the Translator and Allen MacroWare don't use the Re-
vision A OS. These changes can be POKEd into memory if you have
the Translator booted or the XL BOSS installed. For 400/800 owners, if
you have the hardware for making your own PROMs or EPROMs, you
can make these changes into the PROMs and replace them in your
OS board. The same applies for the Newell Industries RamRod
board.

I have tested and used both the Newell RamRod and the Allen
MacroWare XL BOSS and consider them both excellent products and
highly recommend them. Much of the following material was de-
rived from their manuals.

57344          E000           CHARSET1
     You can change the character set directly by POKEing here
     rather than reserving space in memory for an altered set. See
     the section on character sets in the main memory map and
     54017 ($D301). (XL/XE users can change this and the inter-
     national set also.)

59497          E869           ....
     The interval for the keyboard repeat. The original value is 6;
     POKE with 3 to move the cursor twice as fast for repeating
     characters (XL/XE also).

60294          EB86           ....
     To increase the cassette baud rate by almost one-third and re-
     duce the time of the leader from 20 to 10 seconds, POKE the
     following:

     POKE
     Address   Value      Hex
     60294      00     $EB84, $00   low byte, write baud
     60299      04     $EB8B, $04   high byte