Re: Epson APL pinout?

["Michael J. Mahon" <mjmahon@aol.com>]

Tristan Mumford wrote:
> Hugh Hood wrote:
>
>
> >  To: Tristan Mumford
> > Tristan:
> >
> > I have this scribbled down from the time I modified the card so that it
> > would pass the high bit (#7) to my Laserjet Printer for the high ASCII box
> > characters.
> >
> > I don't have anything written down for Centronics pin #10 and later, which
> > means I probably have an incomplete pinout. I'll look at this later, but
> > this should get you started
> >
> >
> >
> > Top of Header on Back of Card
> > ----------------------
> > A  C  E  G  I  K  M  O
> >
> >
> > B  D  F  H  J  L  N  P
> > ----------------------
> >
> >
> >
> >
> > Centronics   Signal     Epson APL
> > Pin #
> > ---------------------------------
> > 1           Strobe         M
> > 2           Data Bit 0     K
> > 3           Data Bit 1     J
> > 4           Data Bit 2     I
> > 5           Data Bit 3     H
> > 6           Data Bit 4     G
> > 7           Data Bit 5     F
> > 8           Data Bit 6     E
> > 9           Data Bit 7     D
> > 10          Ack
> >
> >
> >
> > BTW, if anyone has an Epson APL card and needs to pass the high bit, just
> > cut the jumper wire located at JUMPER P4 on the card. It is just a short
> > to ground for Data Bit 7.
> >
> > I had heard of people modifying their Epson APLs to pass the high bit, but
> > I never could find specific instructions. So, I took out the ohmmeter and
> > traced it myself.
> >
> > Hope this helps.
>
>
> You bet it does! thanks for the tip on making it 8-bit too.
>
> Please tell me this card has at least some bidirectionality. I have a few
> parallel port applications it would be good for. Including:
> * Parallel port sampler.
> * Buffered D/A for pointless sound generating fun
> * Printer
> * T348 Parallel->SCSI adaptor.
> * Various other things.
>
> If it is still mostly unidirectional I can still use it for a few things :)

Well, the ACK line is an input to the card--but if it's compatible with
the Apple printer card, it's read in a very unusual way--it's ORed with
one of the address lines for the slot ROM (where it causes an otherwise
endless loop to terminate by "bank switching" on the fly to different
code).

-michael

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