IWM 344-0041 Integrated Woz Machine pinout

DIP-28. Floppy disk controller

Integrated Woz Machine: the whole Disk II controller in one chip. In the IIc it runs the built-in drive (drive 1) and the external drive port (drive 2). The stepper phases, WRDATA, /WRREQ, RDDATA, WRPROT and the drive selects go straight to the drives. The 344-0041 marking and suffix vary.

Open the interactive IWM pinout

Pins

Pin	Name	Type	Signal
1	SEEKPH0	io	Stepper motor phase 0 to the drive.
2	SEEKPH2	io	Stepper motor phase 2 to the drive.
3	A0	addr	Data written into the state bit picked by A1-A3.
4	A1	addr	State-bit select bit 1.
5	A2	addr	State-bit select bit 2.
6	A3	addr	State-bit select bit 3.
7	/DISK	ctrl	Device enable from the GLU. Falling edge latches A1-A3.
8	WRDATA	io	Serial write data: each 1 bit is a transition.
9	/WRREQ	ctrl	Write request to the drive.
10	D0	data	Data bus bit 0.
11	D1	data	Data bus bit 1.
12	D2	data	Data bus bit 2.
13	D3	data	Data bus bit 3.
14	GND	ground	0 V.
15	D4	data	Data bus bit 4.
16	D5	data	Data bus bit 5.
17	D6	data	Data bus bit 6.
18	D7	data	Data bus bit 7.
19	/DR2	ctrl	Drive 2 select.
20	/DR1	ctrl	Drive 1 select.
21	WRPROT	io	Write-protect input, read as status bit 7.
22	RDDATA	io	Serial read data from the drive.
23	/RESET	ctrl	Reset: outputs inactive, state and mode registers cleared.
24	7M	clock	7.159 MHz clock input.
25	Q3	clock	2 MHz clock that times serial data.
26	+5V	power	+5 V.
27	SEEKPH3	io	Stepper motor phase 3 to the drive.
28	SEEKPH1	io	Stepper motor phase 1 to the drive.

Fitted in

Apple IIc
UniDisk 5.25 In the host Apple IIc (main board), not in the drive

Sources

Apple IIc Technical Reference Manual, IWM pinouts, pp. 247-248