А запустить 486 и глянуть? У тебя 4 микросхемы основной памяти + 1 на четность.
Код:
Pin 	Name 	Description
1	VCC	+5 VDC
2	/CAS	Column Address Strobe
3	DQ0	Data 0
4	A0	Address 0
5	A1	Address 1
6	DQ1	Data 1
7	A2	Address 2
8	A3	Address 3
9	GND	Ground
10	DQ2	Data 2
11	A4	Address 4
12	A5	Address 5
13	DQ3	Data 3
14	A6	Address 6
15	A7	Address 7
16	DQ4	Data 4
17	A8	Address 8
18	A9	Address 9
19	A10	Address 10
20	DQ5	Data 5
21	/WE	Write Enable
22	GND	Ground
23	DQ6	Data 6
24	A11	Address 11
25	DQ7	Data 7
26	QP	Data Parity Out
27	/RAS	Row Address Strobe
28	/CASP	CAS Parity
29	DP	Data Parity In
30	VCC	+5 VDC