You can? O.o I didn't know that.

Word Size
The last feature of the T6A04 is the ability to change the word size from 8-bit to 6-bit. Technically, a word is defined as a string of bits that can occupy a single addressable location. This kind of conflicts with the popular definition of a word being a size of 16 bits, which is due to the fact that Intel made some computers with 16-bit words that were very popular. But this is the official Toshiba name, and I can't think of a better one, so oh well.

The word size is changed with two commands:
$00    Configure six bits per word
$01    Configure eight bits per word
What can we use this for? Well, Toshiba thought it would be nice if computers could have two font sizes, and in fact the 6x8 character routines do use 6-bit word mode to display characters. Maybe we could make a custom large font routine?

Program 26-4

Code: [Select]

    b_call(_ClrLCDFull)
    b_call(_HomeUp)
    LD     HL, text
    CALL   CustomStr
    RET

text:    .DB    "Hello ", 1, 0

CustomStr:
    LD     A, (HL)
    OR     A
    RET    Z

    CP     1
    JR     NZ, NormalChar    ; Trap for char $01 (custom)

    PUSH   AF

    XOR    A                ; Configure word size
    OUT    ($10), A

    LD     A, $05            ; Configure X auto-increment
    CALL   $000B
    OUT    ($10), A

    LD     A, (CurCol)       ; Set LCD Row
    ADD    A, $20
    CALL   $000B
    OUT    ($10), A

    LD     A, (CurRow)       ; Set LCD Row
    ADD    A, A
    ADD    A, A
    ADD    A, A
    ADD    A, $80
    OUT    ($10), A

    LD     DE, Smilie
    LD     B, 8
FontLoop:
    LD     A, (DE)
    CALL   $000B
    OUT    ($11), A
    INC    DE
    DJNZ   FontLoop

    LD     A, (CurCol)       ; Advance cursor position
    INC    A
    AND    %00001111
    LD     (CurCol), A
    JR     NZ, DoneCustomFont

    LD     A, (CurRow)       ; Advance row. This doesn't check for a bad
    INC    A                ; position or scroll. Do that on your own time.
    LD     (CurRow), A

DoneCustomFont:
    POP    AF
    JR     DoneChar

NormalChar:
    b_call(_PutC)

DoneChar:
    INC    HL
    JR     CustomStr

; Our custom character!
smilie:
    .DB    %00011110
    .DB    %00101101
    .DB    %00101101
    .DB    %00111111
    .DB    %00101101
    .DB    %00110011
    .DB    %00011110
    .DB    %00000000