Hi All,

Over the time that I've been involved with the Einstein community
I've known enthusiasts to be absent from contact for long periods
only for them to reappear after researching and developing Einey
projects of benefit to all of us. There are also less fortunate
reasons where active contact has to be put aside for a time for the
fear that Einey interest and enthusiasm will be a distraction for
dealing with other important personal issues such as employment and
family. Members of this group can have varying depths of Einstein
interest and should be able to make postings, not make postings or
just be a passive observer without fear of embarrassment. So please
apologies for absence are not required.

If postings to the group have become sparse then from Phil's latest
post for what is to come, for example (100 documented pages with a
detailed commentary on every routine) will be well worth the wait.
This will be useful information and complementary to making good use
of the compact flash interface that Geoff has shown to work.

I have made an attempt to interface the CF with unfortunate results.
My eyes are not as good as I would like them to be or my hands as
steady. Soldering the closely pitched pins of a CF holder seemed a
bit ambitious for me so I had the idea to push wires into the CF to
hold them in place then use super glue along the rows of wires to
make a rigid and manageable adapter. It may well work but in my case
the glue flooded out the tube and glued not only the wires but wires
to the CF and the CF to the work bench. One useless CF for my efforts.

A problem with hardware developments are that many of us are not
capable when things become too intricate. Ways need to be found to
make building hardware less fiddly even at the expense of a lack of
compactness. With a suggestion from one of Geoff's posts to use a CF
to IDE adapter I had a look on Ebay.
Regularly auctioned
3 x CF to IDE Compact Flash Adapter Male Bootable B03
Buy it now price: £0.99 Postage costs: £3.99
Seller xiandaixg
Just 2P short of £5 for three seems pretty good to me.
Up on the internet I found a pinout for the CF/IDE adapter at
http://pinouts.ru/DiskCables/ide2cf_cable_pinout.shtml

Another problem I had in making up development board for tatung pipe
projects using solder less breadboards was that I wanted to work on
the board in front of the Einstein monitor. The ribbon cable from the
pipe to the front of the computer seemed to be too long to maintain
signal strength. So how close does the CF need to be? The problem of
neatly housing addons becomes more difficult if things just have to
dangle off the pipe.

Another hardware project of my own.

I've made up a link between the Einstein's printer and user port to
the PC printer port. My initial intention to create the link and
machine code hand shaking routines that can be called from basic both
on the Einstein and PC to transfer one byte reliably. I'm leaving
others to decide how the routines can be repeatedly called to chain
bytes for use in their own programming. I've used the byte sending
routines to open a text file on the PC and have it displayed on the
Einstein screen. I have done so as a demonstration and test for
myself to make sure no bytes were missing or duplicated. On the PC
I'm using Bbcbasic for Windows.

I was hoping the link would be a straight forward wiring job but as
Muphy's law would have it this was not how it has become at the
moment. There are a number hidcups which make the link more
complicated.

Hidcup 1: In mode 1 port A the printer port has two hand shaking
lines strobe and acknowledge but there isn't a register where these
handshakes can be read or set. The PIO appears to have its own
automatic hand shaking built in. The strobe hand shake is an output
and I have it attached to the ACK pin on the PC which can be polled
from the status register. There is not a way though to monitor the
input to the Einstein on port A's acknowledge pin. A programming loop
to read port A's data port can't be held for not being able to read
the Acknowledge pin status. Without this ability the same data byte
is read repeatedly instead of waiting for a new byte sent. In the Z80
PIO manual it says the raising edge of the strobe (an import to
acknowledge pin on port A) generates an interrupt (if it has been
enabled). It seems to get the kind of hand shacking required more
sophisticated programming using the interrupt will be needed. Until I
can find a working program example or work out by trial and error how
it can be done I've put using mode 1 aside.

I am instead successfully using port A Einey's printer port and port
b the user port to transfer data. Data from the PC printer port is
sent to port A Einstein's printer port and strobe from the PC to bit
2 busy in the Einey auxiliary register. I'm using port b Einey user
port line 2 bit 0 to toggle acknowledge on the PC.
Hidcup 2: Unfortunately this is not straight forward wiring. Data
outputs from the user port is low in voltage and needs additional
circuitry to make the voltage high enough to set acknowledge on the
PC.

Using port B might make the link more complicated but there is an
extra potential. There are 5 line inputs to the PC status register.
ACK will be needed for normal hand shaking but the other four could
be set by the Einstein's user output for the PC to read 15 different
values for a menu to run different communication services. The user
port could also be used by the Einstein to read 3 bit imports in
addition to strobe from the PC's control port.

Hidcup 3: My present programming on the PC uses access directly to
the I/O registers of the printer port. This is OK with win95 & win98
but it will not work with XP or win2k. BBC4W comes with a third party
utility WINIO which can be used directly for reading and writing to
I/O ports using BBC4W with XP and win2k. I tried using it but it
seemed unreliable some times working some times not. I need time to
read the WINIO documentation if I can understand more fully how it
operates I might see what the problems are.

Once I've decided on the best option to use I'll post hardware and
software details to the group and create a web page for the web site.

I also want to get a CF attached to my Einstein with Geoff's
interface and put the details of the build and software to read and
write to CF sectors up on the web site. For a web site surfers the
build will have to be simple as possible and the mounting and housing
a neat and tidy construction. Something as good as Jose's external
3.5 floppy he built in a vidio case.

Regards Chris Coxall