msx basic full screen editor

By PingPong

Prophet (4093)

PingPong's picture

31-12-2017, 12:15

Hi, to all, i have a question about msx basic full screen text editor.
when a basic statement line is entered and followed by return key, the basic tokenizer parse and generate the tokens and if in immediate mode the statements are executed.
My question is:
Does the basic line have some kind of RAM buffer that is read in order to tokenize the basic line? Or does this buffer is the VRAM itself?
If the basic statement line is read from VRAM how can the tokenizer find the "end" of the basic statement line? There is no statement or line delimiter in VRAM...

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By NYYRIKKI

Enlighted (6016)

NYYRIKKI's picture

31-12-2017, 12:25

Yes, the ASCII version of BASIC line is stored in F55E from where it is tokenized to F41F

By PingPong

Prophet (4093)

PingPong's picture

31-12-2017, 12:40

NYYRIKKI wrote:

Yes, the ASCII version of BASIC line is stored in F55E from where it is tokenized to F41F

thx, but i've also noticed that you can change a line by freely moving the cursor up/down around the screen and then press
What is surprising me is: in this situation does the line got back from VRAM? How can the screen editor find the end of the line, because from the vram point of view the basic listing is a continuos stream of charaters? .... oO

By NYYRIKKI

Enlighted (6016)

NYYRIKKI's picture

31-12-2017, 12:45

Oh yes... That is solved with "line termination table" (LINTTB) in FBB2