PC-9801N-08 (NEC)

I / O expansion unit mounted on 110-pin expansion bus of old 98 note / Epson note.
I / O expansion box (main board mounted) and I / O expansion box interface
It consists of a face adapter and cables.

* Interface adapter for I / O expansion box *

CN1: Amphenol half 110 pin female (connected with the main body of 98 notes)
CN2: Amphenol half 100 pin female (connected with I / O expansion box)
CN3: Amphenol full 50 pin female (externally attached FDD I / F)
SW1: 4 stations DIP-SW
SW2: 10 stations DIP-SW
have.

Device type selection switch setting (SW1)
1 2 3 4
OF ON OF OF PC-9801N (not marked) (factory setting)
ON OF ON ON 32bit CPU model (Refer to the guidebook of each machine)

Memory Addressing Switch Setting (SW2)
Since the timing of memory access differs between the main unit and the expansion box,
It is necessary to set the memory address of the expansion board.
It is also a switch for determining the direction of the data bus.
OFF: 1, ON: 0
1-7: Address upper limit bits 19-13 set, 12-0 bits are 1.
8-10: Address lower limit bits 19-17 set, 16-0 bits 0.
(Example)
1 2 3 4 5 6 7 8 9 10
OF OF ON OF OF OF OF ON (Factory setting)
That is
Upper limit 1101111-1111111111111b = DFFFFh
Lower limit 110-0000000000000000b = C0000h

* I / O Expansion Box *

It has four C bus slots (CN1, 1, 2, 3), of which CN1 is called the main board
As it is dedicated to the interface board, virtually 3 slots can be used.
C bus backboard is called strap switch corresponding to each slot
Jumper pins (SW4 to SW6) are present.

Strap switch settings (common to SW4 to SW6)
2-5 short: For normal option board (factory setting)
3-4 short: When the board has ROM, there is no switch bar

* Main board *

The main board has an anphenol half 100 pin female connector outside
There are 2 places (SW1 / SW2) of 8 series DIP-SW and 2 places of jumper pin (SW3 / SW4) on the board.

Interrupt enable switch setting (SW1)
Number: Function
1: Enable INT0 interrupt (ON: enable interrupt, OFF: disable interrupt)
| |
7: Enable INT6 interrupt (same as above)
8: Always on (always on)
All factory settings are ON

Device mode switch setting (SW2)
1 2 3 4 5 6 7 8
ON OF OF ON ON ON ON ON PC-9801N (not marked) (default setting)
ON ON OF ON ON ON ON OF 32bit CPU model (Refer to the guidebook of each machine)

Setting of SW3
2-5 short fixed

Setting of SW4
2-3 short fixed

* About data line filter *

Noise filter included with PC-9801N-08 connects FDD cable to interface adapter
When attaching it to the FDD cable, the FDD cable should
The attached connector is to be attached to the interface adapter.

Also, a filter is attached to the two connection cables attached to the PC-9801N-08,
Especially the 100-pin cable connecting the main board to the interface adapter is a filter
There is a bias in the position of.This is the connector with the filter on the main board side,
The other connector is to be attached to the interface adapter side.

This setting table was posted by KAZZEZ.
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98 Station (http://www.geocities.co.jp/SiliconValley-PaloAlto/9855/)
-> Switch setting material is also released with peripheral equipment NEC-> IO expansion box PC-9801N-08
It was done.Please refer to it.