MZ-SD²CMT

SD card based CMT for MZ 80K series (MZ-80 K/K2/K2E/C, MZ-80 A, MZ-1200, MZ-700).

Parts Used

1. Arduino MEGA
2. SD card module
3. 16x2 4-bit parallel LCD with 5 x Buttons or 128x32 I²C OLED
4. KEYES IR remote

Examples of what I used:

• an Arduino MEGA 2560 R3 ATMEGA 16U2:
• a 0.91" I2C 128x32 OLED:
• a 16x2 LCD with 5 buttons:
• a KEYES IR remote:
• Dupont Wires to connect the Arduino to the SD card module and the MZ tape connector.
• a LED to show transfer activity.

Installation

You need SdFat, CrystalLiquid, IRremote and SSD1306Ascii libraries: they are available from Arduino IDE.

Wiring

Arduino MEGA Pins:

Name	Number	Direction	Description
A0		<-	BUTTON (UP/DOWN/LEFT/RIGHT/SELECT)
A1		<-	IR remote data line
.	4	->	LCD D4
.	5	->	LCD D5
.	6	->	LCD D6
.	7	->	LCD D7
.	8	->	LCD RESET
.	9	->	LCD ENABLE
RX3	15	<-	MZCMT WRITE
TX2	16	<-	MZCMT MOTOR
OC3B	2	->	MZCMT READ
TX1	18	->	MZCMT SENSE
RX1	19	->	MZCMT LED
SDA	20	->	OLED SDA (I²C)
SCL	21	->	OLED SCK (I²C)
.	50	<-	SD MISO (SD Card MISO PIN)
.	51	->	SD MOSI (SD Card MOSI PIN)
.	52	->	SD SCK (SD Card SCK PIN)
.	53	->	SD SS (SD Card slave select)

LCD Pins:

Name	Direction	Connected to
D4	<-	ARDUINO #4
D5	<-	ARDUINO #5
D6	<-	ARDUINO #6
D7	<-	ARDUINO #7
RESET	<-	ARDUINO #8
VCC	<-	ARDUINO 5v
GND	<-	ARDUINO GND

OLED Pins:

Name	Direction	Connected to
SDA	<-	ARDUINO #20
SCK	<-	ARDUINO #21
VCC	<-	ARDUINO 5v
GND	<-	ARDUINO GND

IR RECV Pins:

Name	Direction	Connected to
DATA	<-	ARDUINO #55
VCC	<-	ARDUINO 5v
GND	<-	ARDUINO GND

SD CARD Pins:

Name	Direction	Connected to
GND	<-	ARDUINO GND
3.3V	<-	NC
5V	<-	ARDUINO 5V
MISO	->	ARDUINO #50
MOSI	<-	ARDUINO #51
SCK	<-	ARDUINO #52
SDCS	<-	ARDUINO #53

LED Pins:

Name	Direction	Connected to
GND	<-	ARDUINO GND
5V	<-	ARDUINO #19

Usage

Wire up as above, and program the Arduino using the IDE.

The following picture is showing how to connect Arduino to 8255:
Note: SDI/SDO/SSI/SSO are signals used for Ultra-fast mode.

• SDI: Serial Data Input, connected to WRITE. Also used to acknowledge Arduino to set the next data bit when MZ reads.
• SDO: Serial Data Output, connected to READ. Also used to acknowledge MZ to set the next data bit when Arduino reads.
• SSI: Serial Synchronisation Input, connected to MOTOR. Only used when MZ writes.
• SSO: Serial Synchronisation Output, connected to SENSE. Only used when MZ reads.

Drop some MZF/M12/MZT files onto a FAT32 formatted SD card, plug it into the mz-sd²cmt, and power on.

An Ultra-fast mode is provided with MZF-like files to allow around 20000 baud transfer. You must press RIGHT button to toggle Ultra-fast mode (disabled by default).

The following picture is showing the ultra-fast protocol when MZ reads:

Legend: * means the MZ reads the READ bit and >< means Arduino is setting the next READ bit. Notes:

• CS is also named SSO.
• PC5 is connected to SDO as the current bit data when MZ reads.
• PC1 is connected to SDI as a read acknowledge sent by MZ.
• PC4 is ignored by Arduino when MZ reads.

Old usage

Drop some LEP or WAV files (converted MZF Files through MZF2LEP tool) onto a FAT32 formatted SD card, plug it into the mz-sd²cmt, and power on.

Tool mzf2lep can convert a MZF/MZT/M12 file into a LEP and/or WAV file in five ways:

• conventional tape data (2 header blocks followed by 2 data blocks) at 1200 baud
• fast tape data (shorter gaps, 1 header block followed by a 1 data block)
• turbo x2 tape data (first turbo loader as a fast tape data then 1 data block read twice as fast)
• turbo x3 tape data (first turbo loader as a fast tape data then 1 data block read trice as fast)
• turbo x4 tape data (first turbo loader as a fast tape data then 1 data block read four times as fast)

Note that WAV files have a limitation: 8-bit mono channel. The frequency can be any, included the usual 44.1KHz and probably even 48KHz. Yes, it works on a 16MHz AVR and probably even on a 8MHz AVR too.

Issues

LEP file is supported. Suffixes .LEP and .L16 are for time resolution 16µs and .L50 for 50µs (As the original LEP from SDLEP-READER - Daniel Coulon). The only interest is for a program needing to read severals blocks. Maybe the same thing can be handled through a MZT file (with multiple data blocks) by listening to MOTOR signal to separate block readings. But unlike LEP, there is no way to say whether the next block is a header block or a data block.

Some programs are a set of blocks in the tape: the first program will read the rest in one or several blocks. Right now, MZF, M12 and MZT don't handle them correctly (no indication whether the next block is a header or a data so you can emit the right prolog). Maybe defining a new binary file with those indication may help to allow reading multiple data.

Turbo x2, x3 and x4 are available through WAV/LEP files built by MZF2LEP tool. However, Turbo x4 may not work perfectly with big program to load.