Lo-tech MIF-IPC-B

The Lo-tech MIF-IPC-B is an 8-bit ISA adapter providing connectivity for Roland MPU-401 MIDI hardware to PC, PC/XT and PC/AT class hardware.

The board features user-selectable operating modes equivalent to Roland's MIF-IPC and subsequent MIF-IPC-A boards, ensuring wide system compatibility and the prospect of running daisy-chained MPU-401 devices from a single host. The board also features user-selectable IRQ and memory address options, enabling multiple cards to be used in a single system. The board is also IBM Personal Computer XT System Board Slot 8 compatible.

A standard DB25 port provides compatibility with the original Roland cables, and is positioned such that the ISA slot bracket from an IBM parallel port card can be used. The board is based on entirely on through-hole 74xx series logic so ease of home assembly.

This PCB is available now in the Lo-tech PCB Store.

Specifications

• Connect Roland MPU-401 to PC, PC/XT and PC/AT class systems using original Roland cable
• User selectable IRQ and memory resources enable multiple cards to be used in a single system
• Original MIF-IPC mode enables daisy-chained MPU-401s
• Powered directly from ISA bus
• IBM Personal Computer XT System Board Slot 8 compatible

Design

• 
• 
• 
• 

Use of this design is provided subject to the lo-tech.co.uk Terms and Conditions.

Bill of Materials

Part	Value	Package	Qty	Farnell	Mouser
C1..6	0.1uF X7R 50V	-	6		594-K104K15X7RF53L2
C7	22uF CPOL-EUE2-5 16V	E2-5	1		647-UVR1C220MDD1TD
C8	47uF CPOL-EUE2-5 16V	E2-5	1		647-UVR1C470MDD1TD
C9	1uF X7R 50V	-	1		810-FK14X7R1H105K
IC1	74HCT688N	DIL20	1	382504	771-74HCT688N
IC2	74HCT245N	DIL20	1	9591931	595-SN74HCT245N
IC3,IC6	74LS08N	DIL14	2		595-SN74LS08N
IC4	74LS33N	DIL14	1		595-SN74LS33N
IC5	74HCT04N	DIL14	1	9591770	595-SN74HCT04N
R1	RESISTOR, 1K, 125MW	0204/7	1	-	270-1K-RC
R2,R3	RESISTOR, 10K, 125MW	0204/7	2	9342419	270-10K-RC
RN1	Bournes Network 4605X-101-103LF	DIL-5	1		652-4605X-1LF-10K
JP1,JP3,JP5	Pin Header, 1x02, 2.54	-	3*		571-5-146278-2
JP2	Pin Header, 2x06, 2.54	-	1*		571-826925-6
JP4	Pin Header, 2x03, 2.54	-	1*		571-826925-3
JP6	Pin Header, 2x02, 2.54	-	1*		571-826925-2
X1	D25S33E4PA00LF	DB25	1		649-D25S33E4PA00LF
DIP-14 Socket	-	-	4	1101346	571-1-2199298-3
DIP-20 Socket	-	-	2	1101349	571-1-2199298-6
-	2-pin jumper	-	5	2396301	806-SX1100-A

*All pin-headers can be cut from a single, 2x15 (30-pin) header eg Mouser 538-90131-0135

ISA Bracket

The board has been designed for use with the ISA slot bracket from an IBM Personal Computer Parallel Card (1501987). The card is mounted to the bracket via the DB25 mount points.

Board Configuration

• JP1 when closed enables IBM Personal Computer XT System Board Slot 8 compatibility. This jumper should be left open except when using the card in PC/XT slot-8.
• JP2 Configures board IRQ. Close any ONE position (Roland default is IRQ2).
• JP3 defines the board operating mode:
  • Open - Roland MIF-IPC-A (for PC/AT compatibility)
  • Closed - Roland MIF-IPC (for PC and PC/XT compatibility)
• JP4 configures the IO port range used, between 300h and 370h (see table below). Roland default is 330h.
• JP5 configures the attachment of unused pins at DB25 socket (X1).
  • Closed - Ground (per MIF-IPC-A)
  • Open - Floating (per MIF-IPC)
• JP6 should be left open.

IO Port (JP4)

IO Port Base Address	A4	A6	A5
300	C	C	C
310	O	C	C
320	C	C	O
330	O	C	O
340	C	O	C
350	O	O	C
360	C	O	O
370	O	O	O

Resources

• Roland Service Notes (1st edition)
• Roland Service Notes (2nd edition)
• Roland MIF-IPC Owners Manual
• Roland MIF-IPC Cable Pinout

See Also

• Lo-tech Audio Boards