Sega SC-3000 Tape Restoration Project

[honestbob]

Hi All

Hopefully some of you will find this interesting. I've had this idea kicking around since I was building the Sega SC-3000 multicart a few years back.

The Sega SC-3000 has lots of neat locally written tape software that was written between 1984 and 1987. But they haven't been widely dumped because tape audio of the original recordings takes up too much space, and some of the original audio is heavily degraded and needs repair to load correctly in emulators and on original hardware. And as yet there isn't a standard compact tape representation format for the SC-3000 like the TZX format.

However from the work on the multicart I know how to digitally re-create the tape audio. Basically if you can reconstruct a perfect waveform of the original audio data then it becomes highly compressible. eg. 16-bit, 44.1KHz mono audio can compress down from around 15MB to around 200Kb or smaller. That's around 75:1 compression. Your mileage will vary, but that is a typical result.

Anyway here is the project page:

http://www.sc3000-multicart.com/sc3000- ... roject.htm

The page is partly for tape dumps, and partly to document some of the techniques used for future reference. I have a couple more ready to go soonish. But life is busy and I've missed my target of two tapes / month for the past couple of months so we'll see The plan is to add to it gradually when I have time.

There are 4 titles up there at the moment. These should load both in MESS and on original hardware.

- The Secret of Bastow Manor (graphic text adventure)
- Vortex Blaster (good shoot-em-up featuring digitized speech)
- The House (graphic adventure by Michael Howard - very quirky)
- Help (general knowledge adventure game by Michael Howard - very quirky)

I also encourage anyone who wants to mirror the zips to do so. I packaged them into zip files with a .txt file describing each release plus scans of the cassette covers. The idea is to ensure that the software survives forever and isn't lost to the sands of time, and the zips are nicely self-contained and reasonably small. The jpgs inside the files actually take up more space than the compressed audio.

There's another discussion thread about it here if anyone is interested.

http://www.smspower.org/forums/15470-SC ... ionProject

Cheers

[tezza]

Great to software restore/restoration projects like this. Sounds great!

[kevman3d]

You might want to contact Shane Farrow at the NZ Film Archive (now known as "Ngā Taonga Sound & Vision Radio Collection")

They have an archive of NZ Games software from the early 70's/80's... Might be worth passing this info on as I'm sure they'd be very keen to archive this stuff as well. The projects been going for a while.

http://www.ngataonga.org.nz/blog/category/video-games-2/

[honestbob]

Thanks Kev, good idea. I've emailed Shane. They are welcome to take anything I post and add it to their archive.

I see they also have a hardware collection, so I've offered to donate a multicart if they want one.

Cheers

[kevman3d]

Cool stuff! I must go and check it out one of these days... The Auckland archive is just down the road from here...

[honestbob]

Hi All

I've added another remastered release to the Sega SC-3000 Tape Restoration Project page. Dungeons Beneath Cairo by Andrew Flexman and David Harvey.

http://sc3000-multicart.com/sc3000-tape ... neathCairo

and here's the rundown on the copy protection they used and the remastering technique I used for future reference.

http://sc3000-multicart.com/sc3000-tape ... aWavWriter

Just out of interest, I had Andrew Flexman get in contact a couple of months back indicating that he would like to release his Scorpion software works to the public domain. I didn't hear back from him after that, but hopefully he is happy enough with the way I've packaged it up. Thanks Andrew

[OldGuy]

Great stuff you have done here, I must dust off my old Sega.

I was the co-author of Vortext Blaster and it is my voice in the game, along with Vortex Blaster we created a space invaders style and pac-man style game.
Trident Technological Systems was made of 2 people and we spent hours writing, marketing and selling these games back in Sydney had loads of fun and it was a special time in computing history mainly as it was pre windows. I also published a Users magazine which was very popular and always included some games.

Although the SC3000 was the main computer I worked with some of the others were, Apple IIe (Edusoft supplied), Amstrad (Cassette & Disc)(Thorn supplied), Sinclair, Commodore Vic20 & 64, Dick Smith VZ200, Tandy TRS80, Toshiba MSX (Toshiba supplied) and a few others.

Cheers
Graham

.

[honestbob]

Hi Graham. It is great to hear from you. Many thanks for lots of hours of entertainment when I was a kid

along with Vortex Blaster we created a space invaders style and pac-man style game

I assume that is Vermin Invaders and Demon Gobbler. Vermin Invaders was a very good space invaders clone, and Demon Gobbler is Pac-Man on acid Very trippy wobbling demons and a toothy Pac Man from memory.

I actually have most of the old TTS titles around somewhere. Are you happy enough for me to keep remastering / packaging them up for release? Assuming I ever get the time of course - life always seems to be busy

Castle of Fear (text / graphic adventure) was another one that caused me hours of frustration. I never did complete that. Text adventures in the 80s were a peculiar exercise in pain and frustration given the limited parsing abilities available. I remember being impressed as a kid seeing how you used the built in SC-3000 Eng Diers graphics characters to draw the screens - I couldn't figure out what the point of them was until then.

A few years back I read through the program and figured out the hashing system you used in the parser and put a little debug output on screen so I could brute force words and see which ones actually matched what the parser was looking for on each screen. I think that got me through the graveyard and up into the castle and into a kitchen or a study or something like that.

Update - I just found my notes on the parsing sytem for that (Dec 2010). I'll have to add those to the tape release. All commands are one or two words and the parser only looks at the first three letters of each word. It then performs a hash on this to transform to a number which is what is used in the basic if / then statements. So it is not trivial to read the program and figure out how to cheat.

I added 21 PRINT A;B;L:FOR BLAH = 0 TO 300:NEXT BLAH

The Parse routine is located at line 900

If you type in say MOVE FLOOR, then A=493 (move), B=459 (floor) and L is the room number

You had an impressive list of titles for the Sega SC-3000 - I think these are all TTS titles:

Vortex Blaster
Vermin Invaders
Demon Gobbler

and Text / Graphic Adventures

Castaway
Castle of Fear
Kingdom
Orb of Power
Time Capsule
Tradewinds
Transylvania Castle of Horror
Underworld of Kragon

[wskiey]

I'm happy to know that there's like this, I'm happy to download this and will include in my back-up.