cpm 2.2 bdos and keyboard

[andromedaa92]

Hi,
how to do the equivalent of kbhit() or wait key pressed with cpm assembler.

function 1 of bdos read, waits for a character to be pressed then displays it on the screen.

I would like the same thing but without displaying it on the screen (echo off)

thanks for your help.

[McArti0]

https://turpas3.angelfire.com/unifirm.pas

Cpm 2.2
CALL #BE9B
DW #BB18 <- Each firmware procedure address

Cpm 3.1
CALL #FC5A
DW #BB18

But its for CPC only

[andromedaa92]

for _kbd_kbhit i use this

_kbd_kbhit:
    call wait_k
    ret

 wait_k:
    LD C, 11 ; C_STAT
    LD DE,0
    call bdos
    OR A
    JR Z, wait_k
    ret

but it don't work, it always loop

[andromedaa92]

my code is for CP/M for agon original CP/M Z80.
i use zcc from z88dk (zcc +cpm .....)

i search equivalent to kbhit() from c language, but don't find anything on internet.

[andromedaa92]

commande line:
zcc.exe +cpm -mz80 -compiler=sdcc -DAMALLOC @/src/text.lst -obin/myprog.com

[McArti0]

Do you want to use the program only on CPC or on any other computer with CPM?

[andromedaa92]

any other computer with cpm with standard bdos call and bios call

[McArti0]

Check if bdos is definitely 5.
I have a different problem. Very often I have A=1 without pressing a key.

[Prodatron]

wait_k:
    LD C, 11 ; C_STAT
    LD DE,0
    call bdos
    OR A
    JR Z, wait_k
    ret

but it don't work, it always loop

Did you try BDOS function 6 C_RAWIO?
https://www.seasip.info/Cpm/bdos.html#6

LD C,6
LD E,255
CALL 5

This will return in A the char or 0, if no char is available. And it will not echo anything.
But it's strange, that you have this behaviour with C_STAT...

[andromedaa92]

yes i tested it work, thank you.

[andromedaa92]

do you know a cp/m 2.2 z80 emulator for windows 10 ?

[Prodatron]

do you know a cp/m 2.2 z80 emulator for windows 10 ?

According to Prevtenet (author of CPvM ) this one is very useful:

https://github.com/MockbaTheBorg/RunCPM

(builds natively on Visual Studio)

[andromedaa92]

thanks for the link