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BASIC_bro
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Joined: 11/05/2026
Location: United States
Posts: 4

Posted: 03:47am 11 May 2026

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Hello, attempting to write something in MMBasic on a PicoCalc, "inkey" looked like the way to go.

After seeing it missed some keys, more searching returned "keydown", but that always returns 0. "Option explicit" suggests it doesn't exist in this version of MMBasic, and is being interpreted as a variable:
" Error : KEYDOWN is not declared"

mm.ver returns 6.0002

Oddly, inkey returns a code for the arrow keys and for delete, but not backspace.
Per the manual, that looks to be expected.
https://geoffg.net/Downloads/picomite/PicoMite_User_Manual.pdf

Is keydown's absence a bug, a case of "we're not done porting" or a feature deliberately left out of the PicoCalc version of MMBasic?

If keydown will not be added, is there/will there be a way to read backspace through inkey or another language feature?

Thanks!

ville56
Guru

Joined: 08/06/2022
Location: Austria
Posts: 508

Posted: 04:33am 11 May 2026

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from the manual:

KEYDOWN(n) Return the decimal ASCII value of the keyboard key that is currently held
down or zero if no key is down. This function applies to USB keyboards and
PS2 keyboards (in MMBasic 6.02.01 or later).

You have version 6.00.02 ...

73 de OE1HGA, Gerald

Frank N. Furter
Guru

Joined: 28/05/2012
Location: Germany
Posts: 1100

Posted: 06:37am 11 May 2026

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...and you don't have a USB or PS/2 keyboard! This keyboard works via I2C...

Frank
Edited 2026-05-11 16:38 by Frank N. Furter

BASIC_bro
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Joined: 11/05/2026
Location: United States
Posts: 4

Posted: 11:05pm 11 May 2026

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Thanks to both of you for your responses.

My confusion probably came from having opened several copies of the manual.

In one (the appropriate one), keydown isn't even mentioned.

I don't remember reading about USB/PS2, which means I probably had
https://fruitoftheshed.com/wiki/lib/exe/fetch.php?media=mmbasic_hardware:mmb4w_user_manual_v0.97.pdf
open. Had I scrolled up on that copy, I'd have seen "MMBasic for Windows". (I might have, and seeing version 5, may have assumed all MMBasic 6s would have it.)

https://mmbasic.com/Download/MMBasic%20Language%20Manual.pdf
has keydown in version 4.5, but does mention a PS2 keyboard.

As for what I was writing, it's working fine, using the delete key for backspace as a stopgap.

Will look into a few of the other languages available for the PicoCalc to see which allow capturing all keys, and paying attention to the versions this time!

BASIC_bro
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Joined: 11/05/2026
Location: United States
Posts: 4

Posted: 03:40am 12 May 2026

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A little more digging, and MMBasic will do what I was hoping.

ON KEY 8, HandleBackspace
...
SUB HandleBackspace()
PRINT "B"
END SUB

Though if you break execution, backspace won't work (del will) until the interrupt is cleared.
ON KEY 8, 0

(Though the interrupt blocks the normal operation of backspace, it does not print B anymore once the program is halted.)

Frank N. Furter
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Joined: 28/05/2012
Location: Germany
Posts: 1100

Posted: 04:48pm 12 May 2026

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Have you heard of this program? Maybe it'll be helpful...

https://forum.clockworkpi.com/t/picocalc-keyboard-testing-in-mmbasic/19794

Frank

BASIC_bro
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Joined: 11/05/2026
Location: United States
Posts: 4

Posted: 06:47pm 15 May 2026

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I have not.

Did run across another interesting issue.

Copying a database onto the device to carry wherever I go (previously kept in a web page on a phone), to make things simpler for version 1, the record format looked like:
chr(1)LF
Samurai CatLF
chr(2)LF
ComicsLF
chr(2)LF
ComicLF
chr(2)LF
By:LF
Mark E. RogersLF
Epic comicsLF
chr(2)LF
1-2LF
chr(2)LF
3LF
chr(2)LF
0LF

All lines terminated by 1 line feed, record delimiter is 0x01 followed by a newline, field delimiter is 0x02 followed by a newline, lines > 50 characters are broken into 50 characters to fit the font-size used without requiring the PicoCalc to reformat.

After a while, this became

chr(1)LF
Title
Samurai CatLF
TypeLF
ComicsLF
SubtypeLF
ComicLF
NotesLF
By:LF
Mark E. RogersLF
Epic comicsLF
HaveLF
1-2LF
NeedLF
3LF
DoneLF
0LF

Then, rather than repeat fieldnames:

chr(1)LF
chr(2)LF
Samurai CatLF
chr(3)LF
ComicsLF
chr(4)LF
ComicLF
chr(5)LF
By:LF
Mark E. RogersLF
Epic comicsLF
chr(6)LF
1-2LF
chr(7)LF
3LF
chr(8)LF
0LF

with the client program turning chr(2) to "=====TITLE=====", chr(3) to "=====TYPE=====" etc.

Until chr(8), which LINE INPUT hiccuped on.

8 and 9 don't work, 10 is in use, 11 works.

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