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
- Arduino MEGA
- SD card module
- 16x2 4-bit parallel LCD with 5 x Buttons or 128x32 I²C OLED
- 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.