P C I O - P O R T A D D R E S S E S

System board I/O map

000-00f 8237 DMA

020-021 8259 INT

040-043 8253 Timer

060-063 8255 PPI XT -064 8742 Ctrl AT

080-083 DMA page reg

0AX NMI mask reg masked=80 unmasked=00

0CX Reserved

0EX Reserved

1F0-1F8 Harddisk Controller

200-20F Game Ctrl

210-217 Expansion Unit

220-24F Reserved

278-27F Reserved

2F0-2F7 Reserved

2F8-2FF 2nd asynchronous communication port

300-31F Prototype Card

320-32F Fixed Disk

378-37F Parallel Printer

380-38F SDLC Communication

3A0-3AF Reserved

3B0-3BF Printer port on display card

3C0-3CF EGA/VGA card

3D0-3DF CGA Color Graphics Adapter

3E0-3E7 Reserved

3F0-3F7 Floppy Disk Drive Controller

3F8-3FF 1st asynchronous communication port

The parallel printer port:

basis address can be 03bc for printer port on video board

0378 for 1st add in printer port (I/O card)

0278 for 2nd add in printer port (I/O card)

03bc data register, output to it loads output latch

0378 on input this address reads back data from output

0278 latch. bit 0 sets pin2, bit 7 sets pin9 of connector.

03bd input reads realtime status

0379 bit 7 6 5 4 3 2 1 0

0279 Busy /Ackn P.End Select /Error - - -

03be output sets,input reads back the control outputs of the port

037a bit 7 6 5 4 3 2 1 0

027a - - - IRQen /Sel In Init. /Autfd. /Strobe

The Game-port