Lynx-cards sizes are : 128KB,256KB and 512KB. 1MB is also possible.

Lynx sees this cards through a port and may not address them directly,
only via a counter, better two counters: one for the block (0..255 on
all cards) the other for the position in the current block (0..4095,
depends on card-size). The postions wraps, so the block has to be
set manualy and the program/game has to know the exact card-size to
allow reads of more the one block.

Ok here's the pin-out:
1	GND
2	D3
3	D2
4	D4
5	D1
6	D5
7	D0
8	D6
9	D7
10	CARD/ (this is OE/)
11	A1
12	A2
13	A3
14	A6
15	A4
16	A5
17	A0
18	A7
19	A16
20	A17
21	A18
22	A19
23	A15
24	A14
25	A13
26	A12
27	SWCON/ (this is WE/)
28	A8
29	A9
30	A10
31	Vcc
32	AUDIOIN (I/O pin but not analog, digital, for 1MBcards used)
33	Vcc
34	SWVCC

Note: A12..A19 is connected to a 74HC164 to select block
      A0...A10 is connected to a 4040 to select postion
      A11      is __missing__
      CARD/ is strobed on reads
      SWCON/ is strobed on writes

    Source: geocities.com/siliconvalley/byte/4242/lynx

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