Table of Contents

DiskIO V3


ECB Disk I/O V3 is a board that provides floppy and IDE interfaces.



Floppy interface

IDE interface


Schematic: ecb_diskio_v3_-_schematics_-_color_1.0.pdf

PCB layout: ecb_diskio_v3_-_board_-_color_1.0.pdf

PCB Gerber files:


Input/Output Ports

Note: Default I/O area (0x20-0x3F) is used in this section. Adjust according to the actual board settings of I/O address area.

20h-23h (aliases 24h-27h, 28h-2Bh, 2Ch-2Fh) - PPI / PPIDE

30h-3Fh - FDC

Jumpers and Connectors

Jumper JP1 - RESET_SEL

Select reset input pin.

Jumper Position Description
1-2* N8VEM SBC. Reset is connected to ECB pin 31C.
2-3 Kontron SBC. Reset is connected to ECB pin 26C

* default

Jumper JP2 - IO_SEL

Select board I/O address area.

Jumper Position Description
1-2 00h-1Fh
3-4* 20h-3Fh
5-6 40h-5Fh
7-8 60h-7Fh
9-10 80h-9Fh
11-12 0A0h-0BFh
13-14 0C0h-0DFh
15-16 0E0h-0FFh

* default

Jumper JP3 - FDC_INT_SEL

Select FDC interrupt output pin.

Jumper Position Description
no jumper* FDC doesn't use interrupts (polling I/O mode)
1-2 Z80 /INT
3-4 Z80 /NMI
5-6 /IQ0 - Wolfgang Kabatzke's ECB-ModPrn board
7-8 /IQ1 - Wolfgang Kabatzke's ECB-ModPrn board
9-10 /IQ2 - Wolfgang Kabatzke's ECB-ModPrn board
11-12 /IRQ0 - John Coffman's Multifunction board
13-14 /IRQ1 - John Coffman's Multifunction board
15-16 /IRQ2 - John Coffman's Multifunction board
17-18 /IRQ3 - John Coffman's Multifunction board
19-20 /IRQ4 - John Coffman's Multifunction board
21-22 /IRQ5 - John Coffman's Multifunction board
23-24 /IRQ6 - John Coffman's Multifunction board
25-26 /IRQ7 - John Coffman's Multifunction board

* default

Jumper JP4 - READY/DC

Configure floppy /READY or /DC (disk change) signals connection.

Jumper Position Description
1-2,3-4* Connect /DC to DIR; Connect FDC /RDY to GND (floppy drive is always ready)
1-3,2-4 Connect /DC to GND (DIR always reads as “disk changed”); Connect FDC /RDY to the /READY signal of the floppy drive. Use with drives that provide /READY signal.

* default

Jumper JP5 - TWO SIDE

Configure /TS (two sides) FDC signal connection.

Jumper Position Description
1-2* Connect /TS to GND (so it is always true)
2-3 Connect /TS to the floppy drive. Use with 8“ floppy drives that provide “two sides” signal

* default

Jumper JP6 - DENSEL

Configure /DEN/LCT (sometimes called /DENSEL, /LCT, or “low current”) floppy drive signal connection.

Jumper Position Description
1-2* Connect Floppy drive's /DEN/LCT signal to the DOR (floopy latch) bit 6.
2-3 Connect Floppy drive's /DEN/LCT signal to FDC. FDC sets this signal for tracks >= 42. Use with 8” floppy drives.

* default

Jumper JP7 - IBM_FDC

Configure 34-pin floppy drive interface (/MOTOR and /DS* signals) to be IBM PC or Shugart compatible.

Jumper Position Description
1-2,3-4* IBM PC compatible. Pins 10 and 16 are connected to /MOTOR signal. Pin 12 is /DS2. Pin 14 is /DS1. Use with up to two PC floppy drives and a PC floppy cable with a twist.
2-3,4-5 Shugart 34 compatible. Pin 16 is /MOTOR. Pin 10 is /DS1. Pin 12 is /DS2. Pin 14 is /DS3. Pin 6 is /DS4.

* default

Jumper JP8 - IDE_VCC

Connect Vcc (+5V) to IDE pin 20.

Jumper Position Description
installed P2 pin 20 is connected to the ground. Some flash IDE modules and CF-to-IDE adapters can use pin 20 for power supply.
no jumper* P4 pin 20 is left open

* default

Bill of Materials (BOM)

BOM Notes

Disclaimer: I did my best to make sure that components listed in this BOM will be compatible with ECB Disk IO V3 board. Obviously I didn't order all of components listed here, and I was not able to actually verify that they will work. Please make sure to double check specifications on manufacturer's and seller's web site before ordering. Please let me know (or update the BOM) if you found any problems or incompatibilities.

Many components have multiple part numbers listed in BOM. There are some differences between various part numbers, such as:

If unsure what to order, read specifications on seller's and manufacturer's web sites. Also please read Replacement Notes below. Finally, consult people on RetroBrew Computers Forum.


Component type Reference Description Quantity Possible sources and notes
PCB ECB Disk IO PCB Version 3.0 1 Order from Andrew
Capacitor C1 - C16 0.1 uF ceramic, 5.08 mm lead spacing 16
Mouser 80-C323C104K5R

Jameco 25523
Capacitor C17,18 22 uF, 50 V electrolytic 2
Diode D1 5 mm LED indicator 1
Connector JP1, JP5, JP6 3×1 pin header 3 Jameco 109576; Mouser 649-69190-103HLF, 649-78229-103HLF
Connector JP2 8×2 pin header 1 Note: This connector is optional. Solder a wire between pins 3 and 4 for default I/O address area (020h-03Fh).
Connector JP3 13×2 pin header

Jameco 53495; Mouser 649-68602-126HLF, 649-77313-824-26LF

Note: This connector is optional. Only required if you wish to use interrupt-driven I/O.
Connector JP4 2×2 pin header 1
Connector JP7 5×1 pin header 1
Connector JP8, P5 2×1 pin header 2 Jameco 108338; Mouser 649-78229-102HLF
Connector P1 DIN 41612
right angle
1 Mouser 617-09-03-396-6921; Jameco 859561, 859430
Connector P2 20×2 pin header shrouded 1 Mouser 737-BHR-40-VUA
Connector P3 17×2 pin header shrouded 1 Jameco 68583, 753547; Mouser 737-BHR-34-VUA
Connector P4 25×2 pin header shrouded 1
Mouser 737-BHR-50-VUA

Note: This connector is optional. Only required for 50-pin Shugart interface, which is normally used by 8“ floppy drives.
Resistor R1 - R4 10 kOhm, 1/4 W 4
Jameco 691104

Mouser 291-10K-RC
Resistor R5, R6 470 Ohm, 1/4 W 2
Jameco 690785

Mouser 291-470-RC
Resistor R7 0 Ohm, or a wire 1 Note: Solder wire instead of this resistor.
Resistor Array RR1 1 kOhm, 9 pin, bussed resistor array 1
Note 1: Use 150 Ohm or 330 Ohm resistor array for older drives that have 150 Ohm or 300 Ohm terminators.

Note 2: Only 6 first resistors are used, so 7 pin or (more common) 8 pin arrays can be used instead. Make sure to align pin 1 properly. Also it is possible to use 10 pin arrays, with 10th pin cut just by the package body.
IC U1 FDC9266 FDC 1 Order from Sergey; Utsource; eBay
IC U2 8255 PPI 1
Jameco 52417

Unicorn Electronics (order 82C55); Utsource; eBay; Ask Sergey
IC U3 74LS273 1
Mouser 595-SN74ALS273N, 512-DM74ALS273N, 595-SN74LS273N, 595-SN74AHCT273N; Unicorn Electronics; Jameco 47386, 308398, 45049
IC U4 74LS245 1 Mouser 595-SN74ALS245A-1N, 595-SN74ALS245AN, 595-SN74AHCT245N; Jameco 47212
IC U5, U6 74LS241 2
Mouser 595-SN74LS241N, 595-CD74HCT241EE4, 595-CD74HCT241; Jameco 47167
IC U7 74LS240 1
Mouser 595-SN74ALS240AN, 595-SN74LS240N, 595-SN74AHCT240N; Unicorn Electronics; Jameco 47141, 308291, 45014
IC U8 74LS139 1
Mouser 595-SN74ALS139N, 595-SN74LS139AN, 595-CD74ACT139E, 512-74ACT139PC, 595-SN74AHCT139N; Unicorn Electronics; Jameco 46623, 301268, 63773, 239011
IC U9 74LS138 1
Mouser 595-SN74ALS138AN, 512-DM74ALS138N, 595-SN74LS138N, 595-SN74AHCT138N; Unicorn Electronics; Jameco 46607, 46608, 301233, 44927
IC U10 74LS125 1
Mouser 595-SN74LS125AN, 595-SN74AHCT125N; Unicorn Electronics; Jameco 46501

Note: This IC is optional. It is only used for “Disk Change” signal readout, which is not supported by the current firmware.
IC U11 74LS32 1
Mouser 595-SN74ALS32N, 512-DM74ALS32N, 595-SN74LS32N, 595-SN74AHCT32N; Unicorn Electronics; Jameco 44134, 47466, 47467, 295515
IC U12,U13 74LS14 2
Mouser 595-SN74LS14N, 595-SN74AHCT14N; Unicorn Electronics; Jameco 46640, 295460, 44935
IC U14,U15 74LS06 2
Mouser 595-SN74LS06N; Unicorn Electronics; Jameco 46359

Note: U15 is optional, and only required for 8” drives.
IC U16 8 MHz oscillator, full can 1
Mouser 815-ACO-8-EK, 520-TCF800-X

Jameco 27991
IC Socket U1, U4 - U6 40 pin 600 mil DIP socket 2
Jameco 41111

Mouser 649-DILB40P223TLF, 517-4840-6000-CP
IC Socket U7, U8 20 pin 300 mil DIP socket 5
Jameco 112248

Mouser 649-DILB20P-223TLF, 517-4820-3000-CP
IC Socket U9 - U13, U24 16 pin 300 mil DIP socket 2
Jameco 37373

Mouser 649-DILB16P-223TLF, 517-4816-3000-CP
IC Socket U14 - U20 14 pin 300 mil DIP socket 6
Jameco 37162

Mouser 649-DILB14P-223TLF, 517-4814-3000-CP
Oscillator Socket U21 - U23 4 pin 300 mil DIP full can oscillator socket 1
Jameco 133006

Mouser 535-1107741

Replacement Notes

File List

FilenameFilesizeLast modified
disk_io_v3_-_complete_board.jpg270.3 KiB2015/11/01 18:49
disk_io_v3_-_component_side.jpg296.7 KiB2015/11/01 18:49
disk_io_v3_-_solder_side.jpg236.3 KiB2015/11/01 18:49
ecb_diskio_v3_-_board_-_color_1.0.pdf1.1 MiB2015/11/01 18:49
ecb_diskio_v3_-_gerber_-_1.0.zip279.8 KiB2015/11/01 18:49
ecb_diskio_v3_-_kicad_-_1.0.zip216.2 KiB2015/11/01 18:49
ecb_diskio_v3_-_schematics_-_color_1.0.pdf265.9 KiB2015/11/01 18:49
max_working_hard.jpg149.3 KiB2015/11/01 18:49