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THAT WAS AT THE NEW LOCATION IS LOST.
CTRL X: THIS WILL EXIT TO EITHER A
MONITOR (OR OTHER PROGRAM) AT $C000
(49152), OR IT WILL COLDSTART BASIC
BY DOING A JMP $FCE2 (64738).
IF YOU WANT TO RESTART THE EDITOR,
FROM A MONITOR IT WOULD TAKE G 1100.
FROM BASIC TRY SYS 4352. THIS ALL
ASSUMES THAT YOU HAVEN'T OVERWRITTEN
IT IN THE MEANTIME.
IN GENERAL, COMMANDS THAT REQUIRE
FURTHER INPUT FROM YOU WILL PROMPT YOU
AS THEY PROCEED. SINGLE LETTER RESPONSES
WON'T NEED A RETURN AFTER THEM.
4 USING THE BLOCKS
YOU SHOULD HAVE GOTTEN A THREE PART,
BASIC LANGUAGE DEMO WITH THIS. THE FIRST
PART, BLOCK.DEMOSTART, IS A ONE LINE
PROGRAM THAT SETS THE START OF BASIC TO
4352, JUST PAST THE END OF THE COLOR-
FILE, AND LOADS THE SECOND PART, BLOCK.
DEMO . THIS THEN LOADS THE CHARACTERSET
DEMOSET, SETS UP THE COLORS, AND SHOWS
THE DEMO.
FEEL FREE TO USE THESE ROUTINES TO
WRITE YOUR OWN PROGRAMS AROUND. THEY ARE
EXTENSIVELY REM'D AND FAIRLY MODULAR.
ONE WARNING - THE BLOCK DRAW ROUTINE
(LINE 9000) WRITES DIRECT TO THE SCREEN
AND COLOR MEMORIES, AND THE X, Y, AND
BLOCK# VALUES ARE NOT RANGECHECKED. IF
YOU PASS VALUES OUTSIDE THE LEGAL RANGE,
YOU WILL EITHER WRITE TO THE WRONG PLACE
OR PRODUCE AN ILLEGAL QUANTITY ERROR.
IF YOU ARE PROGRAMMING IN SOME OTHER
LANGUAGE, THE DEMO SHOULD STILL BE
USEFUL TO YOU IN TERMS OF SHOWING WHAT
SHOULD HAPPEN WHEN IN ORDER TO DISPLAY
BLOCKS.
IF YOU NEED TO HAVE NORMAL TEXT AND
BLOCKS ON SCREEN AT THE SAME TIME, THE
BEST WAY TO GO ABOUT IT IS TO PRESERVE
THE NORMAL CHARACTERS THAT YOU WILL
NEED WHEN YOU EDIT THE SET. IF YOU DON'T
CHANGE THE FIRST 16 BLOCKS DOWNLOADED
FROM ROM, YOU WILL BE ABLE TO PRINT THE
FIRST 64 CHARACTERS NORMALLY AND STILL
HAVE 48 BLOCKS (# 16-63) AVAILABLE.
5 LIMITATIONS
YOU WILL HAVE NOTICED BY NOW THAT
YOU DON'T SEE TEXT AND BLOCKS AT THE
SAME TIME IN THE EDITOR. THIS IS BECAUSE
I'M TOO LAZY TO DO THE SORT OF INTERRUPT
DRIVEN ROUTINE THAT WOULD BE NEEDED TO
SWITCH FROM RAM TO ROM SETS IN MID
SCREEN, AND SINCE THIS IS AN EDITOR
THERE IS NO CERTAINTY THAT THE RAM SET
CURRENTLY BEING USED WILL CONTAIN ANY
PARTICULAR CHARACTER. AHAH! YOU WILL
SAY - WHAT DOES HE USE TO PRODUCE THE
EDIT DISPLAY? THE ANSWER IS THE LAST 4
CHARACTERS IN THE SET. CHARACTERS 252-
255 ARE SET TO THE PROPER SHAPES TO
DISPLAY SOLID BLOCKS OF ALL 4 COLORS
WHEN THE ROM SET IS DOWNLOADED. THE
RESULT IS THAT IF YOU GO TO BLOCK #63
AND START EDITING IT, VERY PECULIAR
THINGS HAPPEN TO THE EDIT DISPLAY.
NOTE THAT THIS DOES NOT AFFECT EITHER
THE ACTUAL BLOCK DISPLAYED ON THE RIGHT,
OR THE SET IN MEMORY (BEYOND THE EDIT
CHANGES THEMSELVES). WHAT THIS ALL MEANS
IS THAT YOU WILL HAVE TO LEAVE #63 TO
LAST, AND ALSO THAT IF YOU LOAD A SET
FROM SOME OTHER SOURCE YOU WILL WANT TO
GO TO #63 FIRST AND CHANGE IT TO THE
EDIT SHAPES.
I'D BE INTERESTED IN HEARING ANYTHING
YOU COME UP WITH IN THE WAY OF BUGS,
QUESTIONS, SUGGESTIONS,ETC. I WOULD LOVE
TO SEE ANY APPLICATIONS YOU COME UP
WITH. I WILL GUARANTEE AN (ATTEMPTED)
ANSWER TO ANY QUESTIONS SENT WITH A
SASE. MY ADDRESS IS:
HENRY VANDERBILT
804 PARKER ST.
BOSTON,MA. 02120
I CAN OCCASIONALLY BE REACHED BY
PHONE AT 617 442-5295. I CAN HANDLE
XMODEM FILE TRANSFERS AT 300 BAUD.
@ Using the Forth Assembler