Persistent Data with ZX Spectrum Core: Saving into TRD, MGT, DSK Disk Images
Howdy’all
Made some experiments with ZX Spectrum core persistence information, here to share some tips...
I am using ZX-Spectrum_20201108.rbf. As the core description mentions, the following is supported:
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1. TR-DOS (Beta Disk Interface) - TRD(read/write) and SCL(read-only) images.
2. G+DOS (MGT +D Disk Interface) and IMG, MGT images (only in non +2A/+3 memory modes).
3. 3 Disk drive usable with +3DOS.
4. Multiface 128 and Multiface 3 (in +3 mode) add-on.
I didn’t try 4. Here’s what worked for me:
- TR-DOS (Beta Disk Interface)
This is indicated as the preferred method (I actually prefer MGT). You can access TR-DOS from 128k menu (TR-DOS option) or by typing RANDOMIZE USR 15616 if you are in 48k classic mode.
Both will take you to a dedicated screen where you can enter TR-DOS commands.
You start by mounting a TRD image file (your ‘disk’) from OSD menu.
Basic commands:
LIST – see what’s in the disk
RUN “filename” – run program from disk
RUN – run “boot” program from disk
SAVE “filename” - same as basic save
LOAD “filename” - same as basic load
RETURN – Leave TR-DOS screen
MERGE, VERIFY, FORMAT, ERASE – did not work for me.
Luckily Mr Gluk Rom allows for some additional operations. You access it by pressing F11. Then its a “one key” thing: Cursor keys to select files, “D” for delete, “T” to label the disk, “R” to rename file, “C” to copy disk, “Q” to quit
G+DOS (MGT +D Disk Interface)
I like this method because it allows to take snapshot and also manipulate files. Google for “MGT PLUS D manual”, its all explained in there.
You start by mounting a IMG or a MGT image file (your ‘disk’) from OSD menu.
Hint: D1 below means “Disk One”
Basic command:
CAT 1 – see what’s in the disk 1.
LOAD D1 “filename”. Abbreviated - LOAD pX - where X is the index of the file (number in first column from the CAT command)
SAVE D1 “filename” or SAVE pX as above.
ERASE D1 “filename” – aaahh this one works
ERASE D1 “oldname” TO “newname”- actually they used the ERASE command to rename files?...LOL…
VERIFY D1 “finaname” - check saves file is ok.
SAVE D1 “file1” TO D1 “file2” - make a copy of file1 to a new file2 inside D1
Snapshots are copies of what is in memory at a certain point in time, good to save game progress. Here the core’s instructions are clear enough: At any time just press F11 followed by 4 to save a 48k image or 5 to save a 128k one. Load as per described above.
3 Disk drive usable with +3DOS.
If you are using the core to emulate a Spectrum +3 (+3 mode) you can load from and save to DSK files. The spectrum manual explains this.
You start by mounting a DSK image file (your ‘disk’) from OSD menu.
Basic commands:
CAT – see what’s in the disk 1.
SAVE “filename” - same as basic save
LOAD “filename” - same as basic load
Also TR-DOS is available in +3 mode so you can RANDOMIZE USR 15616 to enter its menu and manipulate TRD images.
BLANK DISKS TO PLAY
Some ready made blank disks below
Happy 2021.
Antonio