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
     61250      00     $EF42, $00   low byte, baud rate init
                                    routine
     61255      04     $EF47, $04   high byte
     61346      00     $EFA2, $00   baud rate open routine
     61351      04     $EFA7, $04   high byte
     61371      02     $EFBB, $02   leader time

61683-61707          	F0F3-F10B          	....
     Memo pad mode startup message; "ATARI COMPUTER - MEMO
     PAD (CR)."

61709-61718          	F10D-F116          	....
     BOOT ERROR message. This is at 50237 ($C43D) in the XL/XE.

61812          	F174          	....
     Left margin default; initially 2.

61816          	F178          	....
     Right margin default; initially at the maximum 39 ($27).

63227-63229          	F6FB-F6FD          	....
     Key click sound, change these three bytes to 234 ($EA) to dis-
     able the key click sound completely.

64728          	FCD8          	CLICK
     You can also remove the click sound by changing the first byte
     of the routine here to 96 ($60; RTS).

64729          	FCD9          	....
     The buzzer/bell time for warning sound prompts. Initially 127
     ($7F), you can reduce it to any time; 63($3F) is half the time.
     This location also affects the key click sound time.

65217-65221          	FEC1-FEC5          	....
     Default (startup) color value tables. These values are moved to
     the shadow registers 708-712 ($2C5-$2C8) on power-up or RE-
     SET. The screen startup is blue; to change it to black, POKE
     65219 ($FEC3), 0.

65278          	FEFE          	....
     The keyboard table; you can redefine the entire keyboard by
     POKEing here (see the XL/XE map section). One trick is to
     change the keyboard so that the cursor (arrow) keys work on
     pressing, and you have to press SHIFT and arrow to get -, =,
     +, and *, and CONTROL and arrow to get , ,
     , and . Do
     this by:

     POKE
     Address   Value      Hex
     65284      30     $FF04, $1E
     65285      31     $FF05, $1F
     65292      28     $FF0C, $1C
     65293      29     $FF0D, $1D
     65348      43     $FF44, $2B
     65349      42     $FF45, $2A
     65356      45     $FF4C, $2D
     65357      61     $FF4D, $3D
     65412      92     $FF84, $5C
     65413      94     $FF85, $5E
     65420      95     $FF8C, $5F
     65421     124     $FF8D, $7C

     (XL/XE owners: Your keyboard definition table begins at 64337,
     so to use this modification, subtract 941 from the addresses
     given above.)

65281          	FF01          	....
     1200XL owners: You can use your function keys as cursor keys
     by POKE 65281, 30 ($FF01,$1E), POKE 65282, 31 ($FF02,$1F),
     POKE 65297, 28 ($FF11, $1C) and POKE 65298, 11 ($FF12,$1D).

65487          	FFCF          	....
     XL/XE only: To make the HELP key a start/stop key equivalent to
     CONTROL-1, POKE here with 17 ($11). The HELP key returns a
     keycode value at 732 ($2DC) of 17 ($11) for normal use, 81 ($51)
     for SHIFT+HELP, and 145 ($91) for CONTROL+HELP.

65507          	FFE3          	....
     The time delay for the repeat feature; initially 3; POKE with 1.
     See also 65516 (FFEC) below.

65516          	FFEC          	....
     Key repeat delay. Initially 48 ($30); change to 15 ($0F). Do this
     in conjunction with the change at 65507 ($FFE3).