The PCBridge Project

Connect PC cards to your eight-bit ATARI Computer!!!

The idea to develop an interface that enables you to connect PC cards to your beloved ATARI XL/XE arose in 1998 when I wrote my diploma thesis. Since then I pushed the project foreward and spend many hours in the evening on it. Now I have reached a point that I want to publish the work I have done, in order to enable you to build your own interface. And, of course, I want you to invent further drivers for cards I have not considered yet.

Following types of cards are supported in the cuurent driver:

Hercules graphics cards (HGC) in 80 character mode. The driver offers a new Z: handler. The handler can be registered as E: handler in order to replace the existing one.
Up to 4 Serial (RS232) communication cards that use a 16450 (or 8250) style hardware.
The maximun baud rate is 19200 if Antic-DMA is turned on and 38400 baud if it is turned off.
Up to 3 parallel printer ports in standard (uni-directional) mode.

Please take a look at this overview, giving you an idea of the main design features.
Here is a short list of the most important topic:

eight-bit interface conforming to PC/ISA standard.
capable of requesting IRQs. PC's IRQ2 - IRQ7 are mapped to IRQ\ on Atari.
interface copes with wait-states that may be generated by PC cards (e.g. hercules cards!)
implementation conforms to ATARI's PBI (parallel bus interface) specification, so that drivers are imbedded to the ATARI-OS in a plug-and-play manner.
The drivers reside in a 8K ROM from which eight 1K pages can be mapped to $D800 - $DBFF (where the MATH-ROM usually is located).
Uses own 8K static RAM from which two 512 bytes pages are uses in the area from $DC00 - $DDFF.
One page of the PC's IO-address-space is mapped to $DE00 - $DEFF.
One page of the PC's memory-address-space is mapped to $DF00 - $DFFF, the rest of the 24 (16) address-signals have to be set over registers, that can be accessed at $D1FE and $D1FD.

If you want to build the interface yourself or program new driver for it (e.g. ethernet-cards), get the archive mentioned below. The driver software is divided in up to eight parts, for each 1K page one source-code file. By now I have used five pages, which sources you can find in the archive. All constants and variables are separated into two other include files. The code is ATMAS-II compatible, however, since I used include-files, the sources can only be assembled using the A.S.S.I. assembler programmed by McFalkner. I included an older version that works fine for me. If you want to examine the schematic a little bit closer, you may like to download the free version of EAGLE from Cadsoft .

PCBridge.zip
xfddos.zip A little program to list, import, export and delete files from a 90K ATR or XFD image. It was originally compiled with Borland Turbo C.
winsio.zip A simple Windows 95/98/NT/2000/XP(?) programm that emulates a 1050 floppy via a Sio2Pc cable. It has been developed using the LCC compiler for Windows.

You are likely not familiar with ATARI's PBI concept, so I have written a few articles about the PBI and its extension to the full function PCBridge interface:


PBI_Part_1_english	PBI_Part_1_german
PBI_Part_2_english	PBI_Part_2_german
PBI_Part_3_english	PBI_Part_3_german
PCBridge_Part_1_english	PCBridge_Part_1_german

Please contact me, if you do not want to solder your own interface. For roughly EUR 50,-, I will be able to send you the complete interface. Please note that I do not earn even one Cent from it! The PCB is about EUR 40,- and 10,- are for the other parts.

please feel free to contact me: roland_scholz@web.de
pictures of me: roland_getting_employed, roland_working_hard

Changes:

02.Nov.2001: initial page.
03.Nov.2001: Links added, update PCBridge_Part1_german article
04.Nov.2001: Pictures added
10.Nov.2001: English versions of PBI articles added.
20.Nov.2001: English version of PCBridge_Part1 article and GAL-programs to PCBridge.zip added.
myatari.net logo changed.

Links:

Atari Bit Byter User Club

MyAtari online magazine