Multiply DandanatorZX

Multiply is an add-on for your ZX Dandanator! Mini. A Spectrum ZX peripheral with many features.

Multiply does not require any specific file on the microSD to work, you only need a FAT16 or FAT32 formatted SD card with your favourite games and programs.

The formats currently supported are:

• 48k Snapshot. SNA extension.
• 128k snapshot. SNA extension.
• 16k Snapshot. Z80 extension.
• 48k Snapshot. Z80 extension.
• 128k snapshot. Z80 extension.
• TAP files, whether they are single-loading for play or multi-loading. TAPs that use a custom loader (that does not use the spectrum ROM, such as turbo games) will not work.
• SCR files. zx spectrum screens measuring 6912 bytes.
• ROM files that have been generated with the romset generator. They are 512Kbytes

PREPARE FOR THE FIRST TIME THE DANDANATOR V2.X + MULTIPLY SYSTEM.

Before you can use Multiply with Dandanator v2.x, you have to make a small modification that does not affect the normal operation of Dandanator (even if you don't have Multiply connected it will work correctly). If you have a Hobbyretro DandanatorZX you can skip this step.

1. The capacitor next to the right button SW2 and marked C3 must be desoldered.
2. Then, from the bottom of the board, solder a wire between the upper point of where C3 was soldered (the furthest from the ?hole?) to pin 9 of the joystick.

With this we have the Dandanator V2.x ready to use a Multiply as we will have provided a way to communicate the dandanator PIC chip (via TTL serial) with the Multiply Arduino.

The first time (and only the first time) you use Multiply you have to do some steps to prepare the Dandanator and Multiply set. Before upgrading Dandanator you will have a lower romset and firmware than Multiply requires. To make use of this expansion you need version 10.0 (onwards) of both the Dandanator romset and the Dandanator firmware. This 10.0 version of both adds the extra functionality that Multiply requires to function properly.

CREATION OF THE ROMSET AND SENDING TO DANDANATOR

When creating a romset (you can import a previous one that you already have created to update it to v10.0), you have to include the Multiply function, which ?consumes?, in the current version, 32Kb of the EEPROM (of the 512Kb it has). To do so, go to the "Extra" menu and choose "Add Multiply launcher to ROMset".

Once Dandanator has the romset in version 10.0 you have to update the Dandanator firmware. To do this, turn off the ZX spectrum and turn it on with the 2 dandanator buttons pressed. In a few seconds the firmware will be updated.

Remember that you can continue to use DandanatorZX as before, whether Multiply is connected or not.
To access Multiply in the Dandanator menu choose "Launch Multiply". (or the name of it if you renamed it in the ROMset generator).

Using the Multiply menu

Navigation through this menu can be done with Joystick (if you have one clicked on the Multiply) or with keys:

• Q-W-E-R-T keys or Joystick Up
• A-S-D-F-G keys or Joystick down.
• I-P-SYMB SHIFT keys or Joystick right (go to next page)
• U-O-CAPS SHIFT keys or Joystick left (go to previous page)
• ENTER key or Joystick trigger to enter directories or launch snapshots, etc?
• SPACE or 2nd shot key, if you have a Sega type Joystick with more than 1 button, to return to the first item in the current folder or return to the previous directory if you are already located in the first item of the current folder.4
• The cursor keys (or 5-6-7-8 keys) can also be used for up, down and page turning.

The permitted joysticks (without requiring any changes to either the Joystick or the Multiply) are:

• Standard atari joystick
• SJS Joystick (Sinclair Joystick). It is sufficient to have GND on pin 8.
• SMS joystick (Sega Master System) with 2 trigger buttons (both can be used)
• Sega Megadrive Joystick with 3 trigger buttons (B and C button are used)
• Sega Megadrive joystick with 6 trigger buttons (B and C button used)

Remember! Always connect the Joystick BEFORE turning on the ZX Spectrum.

The information displayed in the multiply menu is as follows:
The top blue bar indicates the path on the microSD, initially it is ZX:/ and as you ?enter? folders it will indicate the complete path. If you exceed the character capacity on the screen, only the final part of the path will be shown (the ~ symbol after ZX:/ indicates that the path is longer than it should be). Just below the ?path? we have the indicator of the current page of files in the current folder and the number of pages of the path. The maximum is 99 pages. If there are more than (23 x 99) ? 1 = 2276 files, we will only be able to see the first 2276 files. In any case, although this is a possibility, in order not to slow down the file system, a maximum of 11 pages (23 x 11 ) -1 = 252 files is recommended. Every 11 pages another group of files is "read" from the directory and the content is sorted, which can slow down browsing at these times.

The first icon ?../Dan MENU? allows you to exit Multiply to return to the usual Dandanator menu.

Folders have the folder icon in green. You can log in to navigate through them.
The other icons indicate the different file types allowed (take a look at the information provided by each file type in the box on the right).

Note that Multiply will only display files that it can handle, excluding from the list any other files that are not supported. The filtering level also excludes hidden files and files that have the correct extension but have invalid content. For example, an SCR file must be 6912 bytes long, a Snapshot or TAP file must have a valid header. In addition, if the file is for a Spectrum 128k and you are using a Spectrum 48k, the file will not be listed either.

When entering each folder (or the root folder), Multiply will indicate if the browsing performance in the current folder is degraded because it contains many invalid files: deleted, erroneous or unsupported.
SCR, SNA and Z80 files offer a preview of the screen in the small right window. TAP files will only offer the same type of preview if they have a valid screen inside.

For ROM files that are valid ROMSet files (generated in the generator) you can preview their content and save them in the Dandanator (replacing the current romset). If you select a ROMSet version prior to 10.0 you can also save it but you will be told that it is NOT compatible with Multiply. This means that to use Multiply again you will have to re-record a ROMSET of version 10.0 or higher. Unlike the first time (Multiply was not ready yet), now with Multiply you will be able to burn via serial from the Dandanator menu with the option ?L=Loader? even if you installed a romset lower than 10.0,

so you can forget about the previous methods of serial, divide or audio recording. As you can guess, it is only required that the Dandanator firmware is 10.0 or higher, so if after installing a ROMset lower than 10.0 you update the PIC, you will need to perform the step of recording a ROMset by the previous methods (serial, divide or audio) and update the PIC to firmware 10.0 or higher.

The system boots up as it was shut down last time. In any of these three options:

• basic spectrum
• menu dandanator
• multiply menu

To switch from dandanator to multiply, simply launch it as if it were just another game.
To switch from multiply to dandanator, a directory is "uploaded" from the root in the multiply navigation. It appears as ?../ZX Dandanator? where the ?..? would be, at the top of the list.

Credits

Multiply is a team effort by Dandare, Mad3001 and OverCLK.

LICENCE: CC BY-SA 4.0

Acknowledgements

Our sincere thanks to Habi (Habisoft) for his invaluable support and his great emulator es.pectrum.
Many thanks to Pagantipaco for the graphics and his amazing menu design. Link to Retroworks website
Thanks to Antonio Villena for his modification to the original 48KB Spectrum rom allowing a tape autoload at startup.
Thanks to Bill Greiman for his Arduino SdFat library. The sdfat source code is not distributed with Multiply. SDFat licensing information is available at: https://github.com/greiman/SdFat

Multiply video in operation