Re: Unitron EPROM writer?

["Mark Cummings" <NOTfigjams@primus.com.au>]

Tim,

Excellent pictures, I'll see how I go. BTW nice blue, you don't see that too
often in A2 circuit boards.
Building the header will be a piece of cake, designing it... now that'll be
the hard (read fun) part.
I'll post back here if I need any more info, like where the tracks go on the
component side, which are a bit hard to see when they dissappear under
things.
One thing that does worry me is the missing chip under the ZIF socket. Looks
like it says 74LS14 or something. Also the 7406 missing above the EPROM. Did
you take these out or were they missing when you got it ?
That switch on the end definately looks like it's for Read/Write mode. And I
would say that red LED will come on for Write mode.

Mark


Tim Haynes <trhaynes@yahoo.SPAMBGONE.com> wrote in message
news:HuOx7.184580$sM1.51956121@news3.rdc1.on.home.com...
> Hey Mark,
>
> Okay, I finally got scans of the Unitron.  Here they are:
>
> http://hsr.dhs.org/~timh/UnitronFront.jpg
> http://hsr.dhs.org/~timh/UnitronBack.jpg
>
> What do you think - is building a header within the skills of someone who
> can work a soldering iron and order parts from www.Digi-Key.com (just got
> their catalog in the mail.  Holy chips batman!)
>
> Cheers!
> Tim
>
> "Mark Cummings" <NOTfigjams@primus.com.au> wrote in message
> 3bc442b6@news.iprimus.com.au">news:3bc442b6@news.iprimus.com.au...
> > > Good advice!  I thought about trying this the other night -- after I
had
> > put
> > > away the machines with convenient slot access!  Well, I tried again
> > tonight
> > > in a IIe that I have.  The card wasn't getting recognized in slots 3,
4,
> > or
> > > 7.  Then I hit paydirt in slot 2!  I think it has to do with whether I
> had
> > > the card turned on or off during bootup (yeah, the card has an on-off
> > > toggle!  Crazy).
> >
> > My card has an ON/OFF toggle and matching LED, but that is used to turn
on
> > the programming voltage to the EPROM for burning them, nothing to do
with
> > disabling the card. To read EPROMs the swith stays OFF.
> >
> > >  I think I need to flick the card on while the machine is
> > > booting - if I leave the card in the "on" position before booting, it
> > > doesn't actually come on.  If I want too long to turn it on, it
doesn't
> > get
> > > recognized.
> >
> > Strange
> >
> > > Anyway, when I do pr #2 and get into the software, all I get is a very
> > > simple screen (but hey, at least it's a screen!!).  It says:
> > >
> > > EPROM WRITER USE PR#1-PR#7 ROM SIZE:
> > > 2708=1 2716=2 2732=4 2764=8
> > > ROM SIZE?
> >
> > This is basically all they do, so I think that is all you need. funny
that
> > it says PR#1 to PR#7 and only works in slot 2. maybe it is conflicting
> with
> > other cards. I have discovered by accident that mine doesn't like my AHS
> > card.
> >
> > > If I hit "?", I get a little menu:
> > >     1) WRITE
> > >     2) READ
> > >     3) COPY
> > >     4) MON
> > >
> > > Hitting 4 drops me into the monitor.  I haven't played too much with
the
> > > other options, but they seem to be very particular about the memory
> > regions
> > > that you are interested in reading/writing/copying.
> >
> > normally you drop into the monitor so you can access the disk drive for
> > reading and writing data which is stored in regular RAM. That's why you
> need
> > to boot a DOS/ProDOS disk first otherwise you have no way to save your
> data.
> > OK, except for the tape routines in ROM :)
> >
> > > I think that the four sets of numbers refer to 4 empty sockets on the
> > board,
> > > numbered "08", "16", "32", and "64".  They are 14 pin sockets, but are
> > quite
> > > distinct from the large EPROM socket (which has an open/shut lever,
kind
> > of
> > > like a ZIF socket on a PC motherboard).  There are other populared 14
> pin
> > > sockets, but I don't think they are related to these empty ones - I
can
> > > transcribe their markings, if that sounds interesting.
> >
> > Sounds like your burner uses a 14 pin header socket (dongle) which is
> > plugged into the appropriate 'type' socket to get the right voltages to
> the
> > right pins on the EPROM ZIF socket. you WILL need that bit to get it to
> > work. They should be easy enough to make, but you will need advice from
> > someone who has that exact model so you can copy the dongle. Most likely
> > it'll have a 14 pin header and a few jumpers or resistors, maybe with a
> > plastic hood.
> >
> > There is one other way to make this dongle but it would require
analysing
> > the circuit board to see where the tracks go between the ZIF and the 14
> pin
> > 'type' sockets. or in other words a circuit drawing. If you can't find a
> > someone with the info you are after I may be able to help, but at the
very
> > least I would need a closeup scan of the card from both sides showing
the
> > ZIF and the empty 'type' sockets.
> >
> > Mark
> >
> >
>
>