
    This folder contains electronic and schematic diagrams for the
  cartridge to parallel port interface. The files are:

  CPORTPCB.PLT : Printed circuit board diagram in SCOOTER PCB format.
  RTL_8BIT.IMG : Electronic diagram for the new parallel port.
  RTL_SOLS.IMG : Image showing the 'Solder side' of the PCB (360 dpi).
  RTL_COMS.IMG : Image showing the tracks on the 'Component side'.

  Note that my SCOOTER program (v 2.11C) and manual are in German so
  the whole thing was more a trial and error design. I wish someone
  will improve it.

  Note also that the second 74LS374 is NOT part of the board, in fact
  on my own PCB it's piggy backed on the first 74LS374. Thus they share
  pins 1 and 10 (GND) and pin 20 (+5V). All other pins are on the air
  except pin 11 (small wire to ROM3) and six wires to get the needed
  signals (A13->AUTOFD, A14->RESET and A15->SELECTIN). I know it's
  not very nice, but keeps the PCB very small and SCOOTER's autorouter
  happy ;-)

  Please report any changes to the diagram/board (or possible errors).
  Address line 8 (A8) going to D0 in the parallel port is NOT an error.
  It simulates the missing A0 line of the ROM port, that's why there
  is a lookup table in the software. Normally we could use LDS/UDS
  for that, but my tests showed strange results between different
  ATARI models (ST/TT/Falcon), thus this strange solution ;-)

  If any of you has an idea for a bidirectional design, or better yet
  an EPP board, I'll be happy to hear from you.

  As usual ;-) I'll accept no liability for any damage that might
  result from building this interface. Note that although the ROM port
  can be short-circuited without damage sometimes (except for a bus
  error or similar), great care should be taken when testing your
  newly etched board!

  Vassilis Papathanssiou    Jun 99
  mailto:papval@otenet.gr
