Re: Unitron EPROM writer?

[Stephen Shaw <xstephenx@apple2.org.za>]

On Wed, 10 Oct 2001 22:34:26 +1000, Mark Cummings wrote:

>> 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.
>
All the dongle is is an 8 pin dip switch available at any Radio Shack. All
switches must be on. This is an AP64 card NOT an AP64e. You will find the AP64
marked on the copper side of the card.


> 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

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