BOM

Bill Of Materials

Most of the parts I needed to order came from CPC. For these parts I have provided links.

Resistors

Part Description	Quantity	Part Ref	Notes
0R33 0.5W Carbon Film (Non Inductive)	1	R20	ebay 10mm hole pitch
100R 0.25W Metal Film	1	R16
180R 0.25W Metal Film	1	R21
220R 0.25W Metal Film	2	R6,R13
330R 0.25W Metal Film	1	R17
470R 0.25W Metal Film	2	R7,R14
1K0 0.25W Metal Film	4	R5,R8-9,R18
2K2 0.25W Metal Film	5	R1-3,R15,R23
3K3 0.25W Metal Film	1	R10
3K3 1W Metal Oxide	2	R4,R24	CPC 12.5mm hole pitch
3K9 0.25W Metal Film	1	R12
18K 0.25W Metal Film	1	R11
47K 0.25W Metal Film	1	R22
BOURNS 3296W-1-102LF 1K0 Vertical Trimmer	2	RV1,RV3	CPC
BOURNS 3296W-1-502LF 5K0 Vertical Trimmer	1	RV2	CPC

Note:

1. R19 (4K7) should not be fitted.

Capacitors

Part Description	Quantity	Part Ref	Notes
390p 50V Ceramic	1	C13	CPC 5mm hole pitch
100n 50V Ceramic	9	C3-7,C10,C12,C15,C17	5mm hole pitch
330n 50V Ceramic	1	C1	CPC 5mm hole pitch
4u7 35V Tantalum	1	C16	CPC 5mm hole pitch
10u 35V Tantalum	1	C8	CPC 5mm hole pitch
100u 50V Radial Electrolytic	2	C11,C14	CPC 5mm hole pitch
100u 16V Radial Electrolytic	1	C9	2.5mm hole pitch
220u 16V Radial Electrolytic	1	C2	5mm hole pitch

Inductors

Part Description	Quantity	Part Ref	Notes
Kemet SBC8-221-182 220uH Inductor	1	L1	CPC Do not substitute!

Semiconductors

Part Description	Quantity	Part Ref	Notes
74LS00	1	U10	(3)
74LS02	1	U14	(3)
74LS04	1	U8	(3)
7406	1	U11	(4)
74LS08	1	U9	(3)
74LS138	1	U15	(3)
74LS244	2	U4,U5	(3)
74LS245	2	U3	(3)
74LS374	2	U6,U7	(3)
MC68A21 / EF68A21P	2	U1,U2	(1) ebay
HM6264LP	2	U12,U13	(2)
MC34063AP	1	U16	CPC
LM317T	2	U19,U20	CPC
LM7805	1	U18
2N2905A	2	Q1,Q2	CPC
2N3904	2	Q3,Q4	CPC
1N4148	3	D1-3
1N5819	1	D4	CPC
BZX79-C2V7 Zener	1	ZD4	CPC
BZX79-C3V6 Zener	2	ZD2,ZD3	CPC
BZX79-C4v7 Zener	1	ZD1	CPC
3mm Red LED	1	LED1
3mm Green LED	1	LED2

Notes:

1. Any 6821 PIA rated 1MHz or faster should work, for example: MC6821P, MC68A21P, MC68B21P, EF6821P, EF68A21, EF68B21P.
2. It should be possible to use a single 32Kx8 SRAM fitted in either U12 or U13, but this has not been tested.
3. It should be possible to use 74HCT parts rather than 74LS parts, but this has not been tested.
4. The original used a 7406, I haven't tested an other varients here. It must have open-collector outputs rated for 30V.

Sockets / Connectors

Part Description	Quantity	Part Ref	Notes
8-pin 0.3" IC socket	1	U16
14-pin 0.3" IC socket	5	U8-11,U14
16-pin 0.3" IC socket	1	U15
20-pin 0.3" IC socket	5	U3-7
28-pin 0.6" IC socket	2	U12-13
28-pin 0.6" ZIF socket	1	U17	ebay (1) (2)
40-pin 0.6" IC socket	2	U1-2
2x17 pin 0.1" male header	1	J1	Either header strip or a box header
Cliff DC10A power jack	1	J2	CPC
MULTICOMP PRO MC33263 TO220 Heatsink	1	HS1	CPC
BOYD PF720 TO220 Heatsink	2	HS2-3	CPC

Notes:

1. The ebay link is to a "fake" TEXTODL socket, but the quality seams reasonable.
2. If you are planning to install the board in an enclosure, then socketing the ZIF to raise it up is recommended. Unfortunately I haven't been able to locate a suitable socket that is affordable.

Cables

Part Description	Quantity	Part Ref	Notes
34-way F-F IDC Cable	1		or parts to make one

Miscellaneous

Part Description	Quantity	Part Ref	Notes
MT2-C93401 Relay	3	RL1-3	CPC
PRO ELEC PELL0032 Power Supply	1		CPC (1)
M3 x 30mm PCB standoffs	4		Heatsink protrudes by 25mm
M3 x 6mm machine screw	4

Note:

1. Power requirements are 9V 2A DC centre positive