Attempting to digitize a cassette game, advice?

Champion (352)

07-07-2016, 10:50

Hi,

I decided to spend this summer trying to digitize an old MSX1 cassette game, Talvisota, for personal use, and if necessary (as I expect), restore it to a playable condition. I don't know how badly damaged the tape is, but that doesn't mean I can't try the simplest steps to fix it. I had a friend try and load it on his system and one side started loading but eventually failed, the other apparently didn't even find the header.

If you have advice on how to do this, I'd appreciate hearing them.

My current idea of a workplan is as follows:
1) Read both sides of the C-tape to WAV files on PC (I bought a male-male 3.5mm connector for this purpose, shouldn't that be enough?)
2) See what CAS Tools say about the WAV files.
3) Try comparing the two sides where there may be problems (is there other choice than "visual inspection" in, say, Audacity, or should I use some other free tool?), and fill in what appears to be corrupted spots from the other WAV files.
4) See about cleaning the signal somehow (more volume, noise gating, ...? I've never done any audio editing before.)
5) If I managed to get the program to load, then start fixing the errors - a lot of the game is in .BAS files, and I hope I can do MSX-BASIC sufficiently well to fix most of the corrupted spots, unless I need to parse the tokenized format myself. IIRC there is some BIN part as well, which is where my limited experience falters if it the basic "copy-paste" of signals won't work.

The azimuth etc I didn't understand when I actively used an MSX, and I can't say that I do now either. I'll probably first record the WAV files first with the current setup before trying to adjust the angle or something to see where I can get the "clearest" sound. (My only attempt in early 90s resulted in not being able to load anything from C-tapes any longer.)

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By Buleste

Master (158)

07-07-2016, 12:28

I've found that if you are regularly going to digitise cassettes it's worthwhile investing in a usb cassette recorder. The recordings tend to be of better quality.

Have you considered uploading the .WAV or .CAS files here? I know of a few Finns who would be interested in the game as it looks like it hasn't been dumped before.

By Uninteresting

Champion (352)

07-07-2016, 13:19

An USB cassette recorder is not in my plans - the only games beyond this one I could/might want to digitize are F1 Simulator (Mastertronic) and Laser Squad.

As for uploading, I considered the option, but I'm not too keen on that yet, outside of sending it to be archived. If I did, I'd probably go with the raw WAV file, since I have every reason to expect my fumblings make the CAS file resemble Ecce Homo post-failed-restoration. Maybe someone else could carry the process to the finish line in that case.

By Wild_Penguin

Hero (644)

07-07-2016, 16:05

Whoah, you have original cassette Laser Squad? Is that the same version as in this topic? English version? Any expansion packs / levels?

On topic: I've done cassette restorations myself way back (including Space Satellite, which I haven't found downlodable anywhere! And FC-200 Demo, but I doubt that would be interesting to anyone). Castools is the right tool for the job. I don't think an USB cassette recorder would be optimal in quality (although I don't think quality matters that much, but if you have damaged cassettes, you may want to optimize everything in the chain to remove potential sources of error). It could be handy if you have a lot of cassettes, however.

I saw a thread here just recently with some software / attempts in repairing recorded cassette signals - but I can't find it anymore. I've used myself a tool called "Regenerador" in the past, which seems to just simply maximize the signal IIRC (but that did help with some recordings I got). I can not find it for download anymore, btw.

In my experience, if you can digitize the file without problems (on a PC), it is usually 100% correct. It is known though that the MSX cassette format is very weak in detecting errors (it has just the parity bits...). You could make several recordings (even from the same side or both sides) and if you get the same file(s) repeatedly, it is probably correct. EDIT: I mean this in conjuction with tools like cas2hdd, which will rip the actual files. I'm not sure wav2cas will decode the file(s) internally and create identical .cas files - it might, but I'm not sure

If you manage to load Talvisota on an MSX, you may quite easily play it back (and record that instead!) - since it is (probably?) a tokenized basic came (does it load with "cload"?).

EDIT: There's quite a many very active Finnish MSX users here, and Talvisota is not that rare, so I believe someone is bound to have it already digitized, on their private HD somewhere...

By Wild_Penguin

Hero (644)

07-07-2016, 15:55

Uninteresting wrote:

5) If I managed to get the program to load, then start fixing the errors - a lot of the game is in .BAS files, and I hope I can do MSX-BASIC sufficiently well to fix most of the corrupted spots, unless I need to parse the tokenized format myself. IIRC there is some BIN part as well, which is where my limited experience falters if it the basic "copy-paste" of signals won't work.

I doubt this is worth the effort... there's bound to be someone who has already digitized it, it is quite possible that the cassette is not that much damaged (and can be restored on a PC), and even if you did this, it would not be a "verified good" rip...

Uninteresting wrote:

What tape deck do you have? If it has a monitor speaker, you can adjust by ear: the azimuth is correct when the discant (high end of the spectrum) is as loud as possible. There may be some software for MSX that will listen to a test signal and give a meter on the screen (but I may have been dreaming).

By Uninteresting

Champion (352)

07-07-2016, 16:35

I have an original Laser Squad. I never managed to load it on a real MSX. The game case had just a sticker over the CBM-64 logo (or not even the sticker), so I'm pretty hesitant about the Union Jack/France/Germany flag combination on the back. The game was bought from a Finnish order-by-mail store. To my understanding, no expansion packs or levels.

I haven't managed to load any cassette game since early 1990s (haven't tried either)... so there's no certainty how good the signal still is on the tapes.

By Louthrax

Prophet (2465)

07-07-2016, 16:38

Hi Uninteresting,

If it does not work with CasTools or the other "usual" tools, you can send me the .WAV file, I can try to get something out with SofaCas (you can also try SofaCas by yourself, it's using a different method compared to other tools and gives good results but is a bit complex...).

By Uninteresting

Champion (352)

07-07-2016, 17:51

@Wild_Penguin Getting to play the game again is my main goal, a "verified good rip" isn't something I'm too worried about. If someone did have a working CAS image of Talvisota, I wouldn't turn it down.

The tape deck is a Prelude (or Mark) DW-6000 (I think - made in Korea anyway), and it has a built-in-speaker if you meant that by a monitor speaker?

In any case, the "easy" way (record WAV on PC, pass to wav2cas, see if blueMSX accepts it) failed on both sides of Talvisota and the first side of Laser Squad. Sounds like I'll need to get a screwdriver ready, but that'll have to wait until tomorrow.

@Louthrax Thanks for the link to SofaCas - and I might give a few random tries to see if it does something. Not that I'd know what I'd be doing

By Manuel

Ascended (19469)

07-07-2016, 22:53

I'm also interested in the wav files, if only to check if it loads in openMSX.

That FC-200 demo is also interesting, by the way! I don't think it's dumped.

By Uninteresting

Champion (352)

08-07-2016, 13:00

@Louthrax Thank you! I did some by-the-ear azimuth adjustment and what would you know, your program got something playable out of Talvisota with its default settings Meaning, the loader briefly flashes "Syntax error" without telling which line the error is on before carrying on to the actual game, which is very much unresponsive, bordering on being called unplayable by today's standards. I played it for one turn before stopping. (That's more or less how it was even back then.)

Haven't had as much luck with Laser Squad, though - although having it display a white screen is more than I ever managed back in the 80s.

By Louthrax

Prophet (2465)

08-07-2016, 13:31

Uninteresting wrote:

@Louthrax Thank you! I did some by-the-ear azimuth adjustment and what would you know, your program got something playable out of Talvisota with its default settings

Good, SofaCas is easy to use when the .WAV file is OK (it has lots of options to repair damaged .WAV files, but that's definitively trickier).

Uninteresting wrote:

Meaning, the loader briefly flashes "Syntax error" without telling which line the error is on before carrying on to the actual game, which is very much unresponsive, bordering on being called unplayable by today's standards. I played it for one turn before stopping. (That's more or less how it was even back then.)

Could still be interesting to have the .CAS file of this one, I've not found any dump of this game on internet (and there are not so much Finnish strategy games about defensive warfare against Soviet Union in 1939-40 ).

Uninteresting wrote:

Haven't had as much luck with Laser Squad, though - although having it display a white screen is more than I ever managed back in the 80s.

Ah yes, forgot to mention that Laser Squad can't be converted to .CAS file (it uses a non-MSX audio encoding, so that's just impossible). I can send you a restored .WAV version that you can load with emulator or write back to a real tape if you want (or you can just play the disk version that's on my website).