Help needed with AUX device and device handler

Expert (127)

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.

By msd

Paragon (1078)

07-03-2007, 18:11

Iirc the official ascii rs232 uses the aux..

By Google

By Kwik

Expert (127)

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 (134)

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 (1078)

08-03-2007, 17:41

@kwik: There is no COM device specified

By Kwik

Expert (127)

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 (134)

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 (1078)

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 (134)

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)

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 (1078)

09-03-2007, 14:14

Going to use that for the USB stuff?