Lo-tech MIF-IPC-B

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Lo-tech MIF IPC-B rev.2 PCB

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 board can be purchased online via the TexElec Store.


  • 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


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


See Also