| Author: | Lord Crass (guest: search) |
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| Date: | Tue, Mar 22nd, 2011 @ 00:30 ( . ) |
Alternate Reality: The Dungeon is listed in the database as being signature on track 1 with half of the track being bad data and the other half $AA bytes. It's actually the encrypted custom DOS, just like V-Max's track 20. It loads over the entire $000-$600 drive memory area (yes, right over all of zero page). Basically like restoring a snapshot of the drive state which I'm guessing caused instant problems for any drive not 100% 1541 compatible. Self-modifying decryption routines that dump drive code in the stack area ($100) and command buffer ($200) as well as the regular buffer areas. It's actually quite impressive and the length of the data being spooled in therefore requires 8k drive RAM or a parallel cable to duplicate. It identifies itself as BOSS DOS: BOSS DOS (C) COPYRIGHT 1986 BY INTELLICREATIONS, INC. WRITTEN BY JOHN BUTROVICHV2.4 A quick google search on this turned up an interview with the guy back in '87 where he states that it stood for "Balls Out Super Serial DOS". Apparently the guy is still active in the games programming scene: [link] Interesting stuff. |
| Author: | Lord Crass (guest: search) |
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| Date: | Tue, Mar 22nd, 2011 @ 21:59 ( . ) |
I shouldn't have used the term "encrypted" for the DOS track. It's just a non-standard GCR format that is 1/2 instead of Commodore's 4/5 ratio, but can be decoded in real time before the first byte of the next GCR pair is available at the drive head. This is also an evolution of the custom DOS used in Datasoft's Conan. The GCR decoding routine is almost identical, as is the loading of the DOS from track 1 over top of $000-$400. Not surprising considering the same programmer of BOSS DOS was involved in the C64 port of Conan. The loader for Alternate Reality: The City is somewhere in between. Same GCR format, loader that starts loading into drive ram at $00, but now it overloads into the running routine causing it to execute into an RTS where it proceeds to load the rest of the game. |
 | Author: | hyper active (registered user: 296 posts ) |
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| Date: | Wed, Mar 23rd, 2011 @ 03:44 ( . ) |
check out the protection used on auf Wiedersehen Monty, The Munsters, Flinstones and packmania. Notice any similarities? |
| Author: | Lord Crass (guest: search) |
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| Date: | Wed, Mar 23rd, 2011 @ 19:45 ( . ) |
Yes, they all use the same loader and wasteful GCR format. The bytes that are read in are AND'd with $AA, which results in every nibble being either a $0, $2, $8, or $A before two buffers worth of data are sent back to the C64. The loader is at track 17 and always reads tracks 1-25 (skipping 17 & 18) for all of these games. I didn't look at the C64 side of the loader to see how it rearranges the data it receives. Munsters doesn't seem to have any data after track 25, and seems vulnerable to being dumped from memory after loading. I tried a quick rip with SuperSnapshot and it worked fine. The others are probably the same. I didn't see any signatures in the loader that would indicate who wrote it. |
| Author: | hyper active (registered user: 296 posts ) |
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| Date: | Thu, Mar 24th, 2011 @ 08:48 ( . ) |
it was probably done by the same guy, John Butrovich. |
| Author: | Lord Crass (guest: search) |
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| Date: | Thu, Mar 24th, 2011 @ 11:06 ( . ) |
I don't think so. His DOS was different, as was his GCR encoding scheme. I can't imagine a later version of it being worse than the earlier versions. |
| Author: | Lord Crass (guest: search) |
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| Date: | Thu, Mar 24th, 2011 @ 11:08 ( . ) |
Sorry, I guess I should have clarified. When you asked if there was similarities in those four titles, my response was directed at those four in relation to each other. There doesn't appear to be any relation to the DOS found on the Datasoft titles. |
| Author: | Lord Crass (guest: search) |
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| Date: | Mon, Mar 28th, 2011 @ 22:12 ( . ) |
221B Baker St. also uses BOSS DOS, loaded from track 1, but an earlier version than AR:TD (C) COPYRIGHT 1986 BY INTELLICREATIONS, INC. WRITTEN BY JOHN BUTROVICHV2.3 |
| Author: | Lord Crass (guest: search) |
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| Date: | Mon, Mar 28th, 2011 @ 23:25 ( . ) |
Checked a few more DataSoft titles with custom loaders: Zorro: Early BOSS DOS, like Conan but slightly newer. Pulls the "overload into RTS" trick. States "(.) 1985 `WRITTEN`BY`JOHN`BUTROVICH" Dark Lord: BOSS DOS v2.5 Cosmic Relief: The exact same "23-Track Loader" found on Munsters, Flintstones, Pacmania, and Auf Wiedersehen Monty. |
| Author: | Lord Crass (guest: search) |
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| Date: | Thu, Mar 31st, 2011 @ 22:29 ( . ) |
Black Magic: BOSS DOS v2.3 Force Seven: BOSS DOS v2.5 |