I have more remarks on this (It is an interesting idea!), but that'll have
to wait a bit - I suppose Mr. Philips wants me to do something for him
too :)
g.j.p.a.a.baltissen@kader.hobby.nl wrote:
> As you know, I succeeded in connecting a IDE-HD to a C64. The biggest
> problem was writing the file handling system. The huge amount of work
> involved was one of the reasons I stopped any further development. Another
> reason was that I discovered that there was a much easier way to connect an
> "harddisk" to the 1541 and the only needed hardware is a piece of cable, a 25
> pins male D-connector and a PC (IMHO 386, maybe 286 will do).
>
[snip]
> My idea is to disconnect the above pins (except PB3) and to connect them to
> the LPT-port of an PC.
>
> 6522 LPT
> Name Meaning pin name pin
> ---- ------- --- ---------- ---
> PA0 2 D0 2
> . .
> . .
> PA7 9 D7 9
This will be a problem, since these lines are bidirectional. 286 and 386
printerports mostly don't have a bidirectional printerport. Ofcourse,
you can simulate this by multiplexing the available inputs, but I think
that you'll be running out of time then. (It seems quite time-critical to
me as it is right now anyway).
[snippety]
> By monitoring PB0 and PB1 the PC will know when "to change track". The real
> drive needs a lot of mSec so the PC can take its time to fill a block RAM
> (IMHO only 8KB) with the data of that track.
Remember that the track has to be "GCRed" too. (Or you should use something
like a G64 image from the start). But why doing it on the fly? Memory isn't
really an issue. Since there won't be any other program running, a complete
GCRed image should fit into memory without much problems. You could do
the GCRing (and other needed modifications of a D64 image) when the image
is attached. After that, the only thing needed when the track is being
changed is modifying a pointer (which can be as easy as loading a segment
register with a new value)
--
Martijn van Buul - Pino@dohd.org - http://www.stack.nl/~martijnb/
Geek code: G-- - Visit OuterSpace: mud.stack.nl 3333
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