System Specification for C65: Update 5/1/91

C64DX System Specification UPDATE

F.BOWEN 5/1/91

PAINT x, y [, color]: Working, not completely to the spec. Uses draw pen color and fills emptyness to any border.
RND(0): Improved for better "randomness". Uses unused POT of second SID chip. PCB must allow lines to float.
SET DISK #: (without [TO #] parameter) allows user to clear DS$ message and specify which drive next DS$ comes from.
SET VERITFY <ON|OFF>: The new DOS65 defaults to verify-after-write OFF. This command works with 1581 drive, too.

Negative Coordinates are now allowed for all graphics commands. Some commands require their arguments to be "onscreen", such as PAINT.
BASIC errors now force text mode, and TYPE, LIST, DISK, KEYLOAD, LOADIFF now catch all DOS errors. Autoboot filename= AUTOBOOT.C64DX.*

Opening an RS-232 channel, command string allows setting new features:

        1           baud (0-16, where 16=MIDI rate)
        2           word len
        3           parity
        4           stop bits (not used)
        5           duplex
        6           xline
        7           xon char  (0=incoming flow control disabled)
        8           xoff char (0=outgoing flow control disabled)
        9,10        input  buffer pointer (page lo, hi)
        11,12       output buffer pointer (page lo, hi)
        13          high water mark (point at which xoff is xmitted)
        14          low  water mark (point at which xon  is xmitted)

For debug purposes, the border color will change if an RS232 buffer overflow occurs. To differentiate between aa GET# of a null and a 'no data' null, test bit 3 of STatus (same as C64)

Support for latest DOS controller chip, F011D, includes error LED blink (border color still changes too, for now). Changes to improve FASTLOAD speed and improve SAVE speed. Will work with F011C chip, but error LED does not blink. Requires latest 'ELMER' PAL for disk LED to work correctly for either controller chip. External drive LED will not work correctly until new PCB & F016 chip are designed. New DOS functions include COPY D0 TO D1, ability to change sector skews for file (U0>S#) and directory (U0>D#), and directory compress (i.e., empty trash) via "E" command. Physical interleave is now 7.
The DOS COPY/CONCAT bugs have been fixed, and COPY now allows forms such as COPY D0,"*.SRC" to D1,"*" and COPY D0,"*=SEQ" to D!,"*". Directory/partition paths not yet implemented, but will be.

This page has been created by Sami Rautiainen.
Read the small print.	Last updated April 09, 2006.