[Coco] Re: X-PAD question

[Kenneth Schunk]

Wow, I'm glad somebody still had that tidbit of information. I thought 
I remembered doing something with it years ago, but I haven't found a 
copy of that on my systems here.

Ken
On Jan 8, 2004, at 1:41 PM, Torsten Dittel wrote:

>> What's wrong with the addresses $FF60-FF62 on a Coco3? Look like valid
>> addresses to me.
>
> Ah, you're right. The MaxPak works unpatched at $FF80, this is a 
> problem
> with a CoCo3-upgraded MultiPak interface. There were some hardware
> patches around to move it down to $FF60 (grrr... I should have saved
> that information, now I can't find it any more).
>
> Luckily it looks like I don't have to write a driver, I found that one:
>
>                  Using CoCoMax on the CoCo-3
>                          by Ken Schunk
>
>      This information is public domain. Post it anywhere. Copy it and
> give
>  it to your friends. Line your bird cage with it. Just please leave my
> name
>  on it (Unless you decide to line your birdcage. Then I don't care..)
>
>      Two simple poke's are all that is needed for CoCoMax-2 to run on
> the
>  CoCo-3. The file that must be modified is the COCOMAX/BIN file. To
> modify
>  it to work on the CoCo-3, place a BACKUP of the CoCoMax disk in your
> disk
>  drive and type the following:
>
>       CLEAR 200,&H3FFF
>       LOADM"COCOMAX/BIN"
>       POKE &H53FB,&HFE
>       POKE &H53FC,&HEF
>   If you are using a X-Pad driver, LOADM it at this point.
>       SAVEM"COCOMAX/BIN",&H4000,&H7FFF,&H492B
>
>     That's all there is to it if you can use an unmodified HiRes input
> pack.
>  If you are using a multipak with Tandy's new PAL chip, you will need 
> to
>  modify the HiRes pack to get it to work, since the PAL chip will not
> let
>  you read from the pack. You have a choice of a couple of solutions. 
> You
> can
>  modify the pack to be readdressed below &HFF80, such as &HFF60. This
> will
>  require some knowledge of electronics, since some switching of address
>  lines is required. The other possibility is to use a different PAL 
> chip
>  that allows reading of addresses above &HFF80. I THINK that Spectrum
>  Products may have such a device. Yet another solution would be to not
> use
>  the pack, and use a different device, such as an X-Pad.
>     If you do readdress the pack or use an X-Pad, you will need to
> modify
>  MAXTITLE/SYS to allow it to work with the new device. One poke is all
> that
>  is needed to prevent MAXTITLE/SYS from locking into an endless loop. 
> To
> fix
>  it, use:
>
>     PCLEAR 5
>     LOADM"MAXTITLE/SYS"
>     POKE &HED8,&H21
>     SAVEM"MAXTITLE/SYS",&HE00,&H266C,&HA027
>
>     If you readdress the pack, you will also need to modify COCOMAX/BIN
> to
>  allow it to read the pack at it's new address. The pokes needed are:
>
>     POKE &H562D, (Low order byte of pack address)
>     POKE &H7ACE, (Low order byte of pack address)
>     For example, if you modified to pack to be addressed at $FF60, you
> would
>  use the pokes :POKE &H562D,&H60:POKE &H7ACE,&H60.
>     Remember, these pokes modify COCOMAX/BIN. You first need to LOADM
> it,
>  then do the pokes. Remember to SAVEM it when you are done.
>
>     If you use the X-Pad, you will need a driver for the X-Pad, such as
> the
>  following EDTASM+ assembly code:
>
>          ORG     $5839  ;Start of first mouse area
>   START  CMPB    #2     ;Is it a button request?
>          LBEQ    L2     ;Yes - handle button call
>          LDA     $FF61  ;Read pen Y position
>          DECB           ;B has 1 if Y and 2 if X
>          BNE     L4     ;Skip if call was for Y
>          LDA     $FF60  ;Get pen X position
>   L4     LDY     #TMP   ;Point to data storage
>          STA     ,Y     ;Save pen position
>          CLRB           ;Point to data with B,Y
>          RTS            ;Back to CoCoMax
>   TMP    RMB     1      ;Data area
>          ORG     $562A  ;Start of second mouse area
>          LBRA    START  ;Jump to read if called here
>   L2     LDA     $FF62  ;Read pen status
>          ASRA           ;Get pen switch bit to 'C'
>          BCS     L3     ;Return pen down info
>          LDA     #$80   ;Map in expected pen value
>   L3     LBRA    L4     ;Return value to COCOMAX
>          END     START
>
>     Enjoy
>
>
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