Re: What's this then? - Sinclair

This is a discussion on Re: What's this then? - Sinclair ; Tim Fardell wrote: > > If you are interested, I can provide instructions on how to dump the data > > from these ROMs and get it to a PC (assuming you have access to a working > > ZX81), ...

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Thread: Re: What's this then?

  1. Re: What's this then?

    Tim Fardell wrote:

    > > If you are interested, I can provide instructions on how to dump the data
    > > from these ROMs and get it to a PC (assuming you have access to a working
    > > ZX81), or I would be very happy to provide that service if you're interested
    > > in letting me borrow or buy the circuit from you.

    >
    > It is winging its way to you as I write this! Looking forward to finding
    > out what it is :-)


    I've now dumped the ROM data, and can confirm that it is mostly the
    same as the dk'Tronics ROM. Interestingly one of the character sets
    has been changed; while the dk'Tronics ROM provides a set that is the
    inverse of all the usual characters, the Kayde ROM provides an
    additional Pac-man set.

    Both ROMS have the character set selection routines in the last
    512-byte area of the ROM, which occupy 60 bytes, but the rest of that
    area is unused - seems like prime real estate for some useful routines,
    but I guess that would have been additional development expense, as
    well as reducing the opportunity for additional toolkit ROM releases
    (of which I've not seen any evidence).

    I've put the ROM, character set, and a few photo's/scans on my web site
    here:
    http://www.zx81stuff.org.uk/zx81/gen...ayde4KRom.html

    Cheers, Simon
    ZX81 stuff: www.zx81stuff.org.uk


  2. Re: What's this then?

    Oh, and I should add, thank you very much for donating this, allowing
    me to preserve it on my site.

    If anyone else has got any interesting ZX81 hardware/software that's
    not already on my site, donations are welcome :-) (I'll pay reasonable
    postage).

    Thanks, Simon
    www.zx81stuff.org.uk


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