Help needed with AUX device and device handler

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By Kwik

Expert (127)

Kwik's picture

07-03-2007, 16:29

Hi,

What is the AUX device used for on msx? Are there any programs around that use it? I found that the diskrom provides two hooks for it; reading and writing.

How exactly do you create your own device. I know the device handle in the rom header should be used. However, the diskrom does not use it although it does provide 5 devices (PRN, LST, CON, AUX and NUL). I could not find much information about it.

Any documentation about the subject is welcome.

Thanks in advance.

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By msd

Paragon (1233)

msd's picture

07-03-2007, 18:11

Iirc the official ascii rs232 uses the aux..

By Kwik

Expert (127)

Kwik's picture

08-03-2007, 14:22

That's strange... The AUX device is provided by the diskrom. An rs232 device provides its own device (COM) why would it need to use the AUX device?

By zeilemaker54

Master (154)

zeilemaker54's picture

08-03-2007, 16:46

The diskrom provides for the AUX device, because of the CP/M compatiblility. CP/M has some functions for the AUX device. The diskrom provides some hooks, to link AUX to the MSX-Serial (&HF327 for AUX in, &HF32C for AUX out).

By msd

Paragon (1233)

msd's picture

08-03-2007, 17:41

@kwik: There is no COM device specified

By Kwik

Expert (127)

Kwik's picture

08-03-2007, 20:13

I did find some information on creating a device handler in the msx technical handbook. It is specific for rs232 devices, and doesn't go into much detail. Does anybody know a good source on how the create a device handler?

I'm interested in the parameters of the following functions.

        dw open                 ;  0
        dw close                ;  2
        dw randomio             ;  4
        dw seqOutput            ;  6
        dw seqInput             ;  8
        dw loc                  ; 10
        dw lof                  ; 12
        dw eof                  ; 14
        dw fpos                 ; 16
        dw backup               ; 18

By zeilemaker54

Master (154)

zeilemaker54's picture

08-03-2007, 21:05

If you want to know more about MSX-serial programming, you should read this:
www.classicgaming.com/epr/msx/232bcal.txt
To use this info, you should know something about using Extend BIOS Calls (&HFFCA), but that is available in the MSX technical databook. If you need more help, let me know.

By msd

Paragon (1233)

msd's picture

08-03-2007, 21:24

This is what the dos2 reference manual says about AUX : The AUX device mentioned above does not do anything by default, but a routine may be hooked into it so that it refers for example to a serial driver. The NUL device does not actually do anything; output characters are ignored and an end-of-file is always input. The LST and PRN devices are identical.

By zeilemaker54

Master (154)

zeilemaker54's picture

09-03-2007, 09:51

If I remember correctly, there is a offical tool which connect AUX to the MSX-serial by means of the mentioned hooks. May be it is on Datapack disks, but I am not sure.

By Kwik

Expert (127)

Kwik's picture

09-03-2007, 13:24

@zeilemaker: Thanks for you link. Together with the information in the MSX Technical Handbook, it provides all the info i need (i think). I was a bit confused about the difference between a standaard MSX rs232 and a device. If i am correct, the MSX rs232 is just another device (called at 0x4006), but to make it a standard MSX rs232, it should also be accessible with an EXTBIO call? Right?

By msd

Paragon (1233)

msd's picture

09-03-2007, 14:14

Going to use that for the USB stuff?

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