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Help identifying hardware peripheral

MuzerMuzer
edited November 2009 in Hardware
A few months ago someone gave me all their Speccy stuff. The Spectrum itself was broken, but I got with it quite a few useful peripherals. Among these is a small black box, with a green Spectrum connector (not ZX81-compatible), a 2-way switch and a DE9 male port (aka standard 9-pin Atari Joystick-style). I've done a few preliminary tests and it appears to do exactly nothing (though the tests entirely involved me plugging in a joystick and waggling it to see if it would type letters/numbers :p). There is no clue on the box itself what it is or what it does (it is completely black aside from the green connector). On the PCB there are quite a few ICs, it seems to be made in the old green ZX81 style (smooth, flowing tracks rather than straight ones), and a capacitor or two. The board is marked with "ISSUE 2" and there is an upside-down M with a horizontal line through it near the middle.


Not knowing much about Spectrum hardware, is there a way I can test this to see what it is from the Spectrum? Does anyone know what it is?
Post edited by Muzer on

Comments

  • Dr BEEPDr BEEP
    edited November 2009
    Muzer wrote: »
    A few months ago someone gave me all their Speccy stuff. The Spectrum itself was broken, but I got with it quite a few useful peripherals. Among these is a small black box, with a green Spectrum connector (not ZX81-compatible), a 2-way switch and a DE9 male port (aka standard 9-pin Atari Joystick-style). I've done a few preliminary tests and it appears to do exactly nothing (though the tests entirely involved me plugging in a joystick and waggling it to see if it would type letters/numbers :p). There is no clue on the box itself what it is or what it does (it is completely black aside from the green connector). On the PCB there are quite a few ICs, it seems to be made in the old green ZX81 style (smooth, flowing tracks rather than straight ones), and a capacitor or two. The board is marked with "ISSUE 2" and there is an upside-down M with a horizontal line through it near the middle.


    Not knowing much about Spectrum hardware, is there a way I can test this to see what it is from the Spectrum? Does anyone know what it is?


    1 switch with 9 pins?

    Could be a programmable joystick interface.

    1) Does the computer accept keys when interface is set to left?
    2) When switch is right, press enter and switch to left. Release key.
    Does the computer keeps entering ? If so, you have a prog. interface.
  • ZupZup
    edited November 2009
    It may be a "programmable" joystick interface. Those things allowed you to map joystick movements to keys.

    Why don't you post some pics? Someone else would identify your hardware.
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  • MuzerMuzer
    edited November 2009
    Dr BEEP wrote: »
    1 switch with 9 pins?

    Could be a programmable joystick interface.

    1) Does the computer accept keys when interface is set to left?
    2) When switch is right, press enter and switch to left. Release key.
    Does the computer keeps entering ? If so, you have a prog. interface.
    It isn't left and right, it's up and down, but I'll try ;)

    EDIT: No and no.
  • MuzerMuzer
    edited November 2009
    Pics:

    zipped in DOWNLOAD: http://hbcapps.com/miight/crap/dump/fileVFmflu.zip ORIGINAL NAME: unidentified-hardware.zip

    (why doesn't this forum allow attachments?)


    Sorry for poor quality; camera phone + crap energy saving bulb = not good :p
  • jpjp
    edited November 2009
    Muzer wrote: »
    It isn't left and right, it's up and down, but I'll try ;)

    EDIT: No and no.

    Just a couple of thoughts:

    I can only imagine that the switch is used to change protocol of whatever (see later) is plugged into the hardware.

    For joysticks, the industry standard was Kempston and that does not display characters (e.g. keywords/letters/numbers) when the joystick is moved around.
    The Kempston specific manual (found here) gives a short program you can type in to test functionality.

    That's all well and good, but your Spectrum is broken so you can't type the program in ... :(

    So, if it's not a joystick interface then perhaps it's for a Mouse?

    I imagine the hardware specialists could shed some light with photos of the PCB...
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  • MuzerMuzer
    edited November 2009
    No no, I have another Speccy (a +2) that someone gave me earlier (I seem to be quite lucky on getting stuff for free) - I'll try it on that.
  • MuzerMuzer
    edited November 2009
    OK, it doesn't seem to be a kempston interface exactly (either that or the joystick I picked out is not Atari-compatible) but it definitely does something; moving left or right breaks into the program (WTF?), any button seems to stop keyboard input and make the numbers in that program go crazy, and I haven't tested fire yet...


    EDIT: With the switch in the other position, it seems to do (wait for it) Nothing!



    This is all in 48k mode, haven't gone near 128k mode...
  • spiderspider
    edited November 2009
    Random thought:

    Could it not be a joystick interface at all and be some kind of serial (RS232?) interface perhaps ? :-?


    I wonder if we need to see pics of the internals (particularly what chip(s) it has) to diagnose further.
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  • MuzerMuzer
    edited November 2009
    Internals:

    filelhb3KF.jpg

    Chips say:

    Top left: NEC Japan 8333A5 <micro>PD2114LC -3
    Second one down on left: same as above
    Third one down on left: <two wavy lines>-827 DM7432N
    Fourth one down on left: unreadable (rubbed off or something)
    Top-right: El Salvador 240C SN74LS367AN
    Second one down on right: Portugal 8323C SN74LS11N
    Third one down on right: Same as above
  • BloodBazBloodBaz
    edited November 2009
    I was just too shocked to focus on the identification problem at hand once I saw a C64 in the background of a couple of your shots!!. :grin:
  • rokoroko
    edited November 2009
    I read the marking not as M but as AH.
    2/3 of it looks like a programmable joystick intf, probably comparable with the DK'Tronics one, of which I uploaded the diagram today > available soon.
    1/3 (around the 74LS367 buffer) is unknown, could be autofire or 'slowdown control'?
  • MuzerMuzer
    edited November 2009
    BloodBaz wrote: »
    I was just too shocked to focus on the identification problem at hand once I saw a C64 in the background of a couple of your shots!!. :grin:
    That would have been a VIC-20, my C64 is on top of my cupboard (so out of sight). I'm surprised you didn't notice any more - I'll take another look at the pictures to see what I got...


    EDIT: I've looked and you can also see some Vectrex games (above the VIC-20), some Amiga games (in boxes on the lower-left of some pictures), and in the first one you can see my peripherals draw (most prominently featuring SNES and Megadrive lightguns).
    2/3 of it looks like a programmable joystick intf, probably comparable with the DK'Tronics one, of which I uploaded the diagram today > available soon.
    How would I use this?
  • rokoroko
    edited November 2009
    Muzer wrote: »
    How would I use this?
    Really would'nt know, never used it. I am just a 'taking-things-apart' kind of person.
  • PilsenerPilsener
    edited November 2009
    ?pd2114LC-3 is a 1024x4-Bit-SRAM chip. Seems to be 300 nS.
    I wonder what it's supposed to store.
  • MrCheeseMrCheese
    edited November 2009
    Pilsener wrote: »
    ?pd2114LC-3 is a 1024x4-Bit-SRAM chip. Seems to be 300 nS.
    I wonder what it's supposed to store.

    Wouldn't it having it's own ram (=buffer) support it being some sort of RS232 interface rather than a joystick interface?
  • rokoroko
    edited November 2009
    MrCheese wrote: »
    Wouldn't it having it's own ram (=buffer) support it being some sort of RS232 interface rather than a joystick interface?
    An RS232 intf of this magnitude would have a crystal, large UART and line receivers/drivers 1488/1489 on board.
  • Alcoholics AnonymousAlcoholics Anonymous
    edited November 2009
    Yeah it's not an rs232 interface. The small SRAM (two 1k x 4) is probably to store programmed keypresses. I'd say it's a programmable joystick interface with the switch possibly selecting between program mode and joystick mode.

    In the switch position that doesn't generate keypresses, try pressing a single key while moving the joystick in a single direction. Then with the switch in the other position (joystick mode?) see if the same joystick direction generates that key. Just a wild guess, really :P
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  • PilsenerPilsener
    edited November 2009
    Wouldn't a programmable joystick interface require some kind of ROM to hold the software for the programming ?
    Or else it would require a bit of software to be loaded from tape before every game was loaded (I think).
  • rokoroko
    edited November 2009
    Alcoholics Anonymous wrote: »
    In the switch position that doesn't generate keypresses, try pressing a single key while moving the joystick in a single direction. Then with the switch in the other position (joystick mode?) see if the same joystick direction generates that key. Just a wild guess, really :P
    From the DKtronics diagram (in 'Whats new') I take that this intf is not reacting on IN31 and therefore NOT kempston. Just returning keypresses then, after the programming session.
    @Pilsener: The joystick just 'learns' the relevant keys.
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