Tape player and recorder for Sinclair ZX Spectrum on Atmega128

About ZX Spectrum

ZX Spectrum - a computer designed over 30 years ago with a 3.5 MHz processor and only 48 KB of RAM. For him, it developed a huge number of software and games. Moreover, new game releases are constantly in our days.

Previously, the program is loaded from the tape. And the loading is not always succeeds, sometimes the game had to try several times to load often getting message "R Tape loading error".

Alternatively audiotapes today suggests a memory card that stores the program files in the formats TAP, WAV and TZX. And as an alternative to tape recorder - microcontroller device that can play and store these files.

The recorder circuit

The circuit of such a device is shown below:

The recorder is implemented on a microcontroller ATMega128, running at a clock frequency of 16 MHz. Resources of the MCU should be enough to implement all the necessary functionality and to improve it in the future.

Voltage regulator can be designed either on IC2-chip or on IC3-chip. The circuit shows both chips but in a real device should be installed, only one of them. If the device is supposed to integrate into the computer or powered from the power supply voltage not less than 5V, the chip IC2 (and inductor L1 and diode D1) must be excluded from the circuit. Otherwise it is necessary to exclude the chip IC3 from the circuit. In this case, it will be used boost voltage regulator on chip IC2, and for the supply scheme will need two 1.5V AA/AAA power elements.

The device uses the display of the Nokia 5110 and the 5-button joystick.

On-chip IC4 are made real-time clock. As IC4 can be used either PCF8583T or PCF8563T (which are designed for two different versions of the firmware).

Also, the device has a speaker for listening to the record / playback files. The speaker volume can be adjusted by the variable resistor.

To connect to retro-computers the device has "mini jack" sockets - input and output.

Appearance of the assembled circuit board in front and behind:

Assembled device:

The firmware and user-interface

The main menu of the deveice:

Here you can go to

1. playback file from memory card
2. save file to memory card
3. settings of the user interface, date/time and input/output signal timings
4. information about SD/SDHC memory card (size, type, used- and free-space, vendor, cluster size etc.)
5. information about the device and firmware version

In the selection of the first menu item opens a file browser

After selecting the file it starts loading. The screen displays the number of blocks in the file and the current block number as well as the time elapsed since the start of the loading. Loading can be stopped by pressing the Pause button. In pause mode, the keys up and down you can select the block from which you will continue playing (useful for games with loadable levels).

When you save a file to a first input file name:

Navigating the on-screen keyboard - with cursor. Enter a character - the central key. To cancel the save enter an empty name.

After entering the name of the device will wait for receiving data from the computer. Then the screen will display number and size of blocks.

On the Settings screen, you can select the language (English or Russian), enable or disable keyboard sounds on load- and save-operations. Also here you can setup the screen highlight, the playback speed (x1, x2, x4, x8) and the current date / time

Also you can customize the TAP-form parameters:

• Pause: the delay between the blocks in milliseconds
• Pilot: the duration of the pilot signal in milliseconds
• Pilot.l: the pulse duration of the pilot in microseconds
• Sync 1: the first synchro pulse duration in microseconds
• Sync 2: the second synchro pulse duration in microseconds
• Data: the data pulse duration (for "0" bits)
• Capture: capture mode when receiving data from the computer

Also here you can reset the settings to default values or define them in the form of a signal from the computer.

Files

Next on the links, you can download the Eagle project and firmware.

zx-tape-loader_8563_v1.1.hex (firmware for PCF8563T)
zx-tape-loader_8583_v1.1.hex (firmware for PCF8583T)
zx-tape-loader_8563_v1.1.1.hex (firmware for PCF8563T)
Eagle-project
Circuit in pdf
Circuit in png, big resolution
Fuse-bits

Buy a device

There are devices with a 128x128 color display. The latest version of the firmware supports the playback of TZX files (partially) and firmware upgrade from the SD card.
You can buy from us a fully assembled and tested device with worldwide shipping.
The cost of device: 55 USD (shipping is paid for separately, around 15 USD)
To make the order please use the site feedback form.

Here are some photos and screenshots of the new version:

Warning!
Now on ebay you can see this tape recorder. This is not my device, it uses an old version of the firmware and there are errors in the circuit - the function of recording from the original ZX-Spectrum may not work.The latest firmware versions are now closed (there is support for TZX and a has lot of improvements and bugs fixed). Be careful.

Because of such piracy, the firmware of the new version of the device has been closed. Now the firmware file is encrypted and binded to the serial number of the device.