As I remember, the effect of the laser burn was to "freeze" some bytes in one sector...you could read them but not change them. The test was to write it with all zeroes, read and compare with all zeroes, write with all ones, and compare with all ones. The burn would always create a compare error somewhere in the sequence.
I remember a primitive attempt at this in the copy protection routine for dBase III way back when the DMCA was but an industry wet dream. This was the ProLok Disk, the one with the laser burn.
There was a section of code hidden by about forty layers of byte-by-byte XORing against bytes looked up in a table. At each level, it would intercept the Debug and Single Step interrupts, XOR the next layer, and jump into it. In those floppy-only days, it had to be reverse engineered a layer at a time, each step producing a disk with one less layer. Approximately the 40th disk had the actual copy-test code...which turned out to be pirated code!
This was also before BIOS shadowing in RAM, and the BIOS executed straight from ROM. The test for the laser burn required hooking into it, which of course they couldn't do in ROM. Instead of working out their own shadowing routine they copied some 700 bytes of the IBM Fixed Disk BIOS, inserted their hooks, and then made a weaselly attempt to cover their tracks by interchanging logical-shift with arithmetic-shift instructions wherever it was guaranteed that nothing would go through the carry bit.
And all that meshugass was there only to hide the publisher's own piracy...the copycrack consisted of a two-byte change elsewhere on the disk.
That idea was mentioned, at least at the brainstorming level, in the Moon Race days. There was a proposal to send a crew one-way with lots of supplies and a promise to follow up with a return vehicle a year or so later.
It was also suggested that they should be armed in case the Russians arrived and tried to take their supplies.
And a film you don't often see on the tube without some editing. A frequently-appearing character in it is the squadron commander's black Labrador, whose name didn't cause any problem in a wartime British film but would not go over well on USAn TV today..
Come to think of it, there was another charmer: a French grad student in linguistics who was on her way home after a year of teaching French at Sydney University. Grammatically perfect English with a mixture of French and Oz color...she struck up a conversation with me and the wife so she could classify our accents.
I had the pleasure of working around some of the Paperclip crowd when I did my MS thesis at Wright-Patterson AFB in 1964: Hans von Ohain, who had raced one-on-one with Frank Whittle to get the first jet engines flying, was the head of the Aerospace Research Lab there and my thesis advisor was a lower-level guy named Erich Soehngen. He had the ultimate excuse for not having a Ph.D: The Eighth Air Force dropped one on his dissertation in 1944.
Most charming accent I ever heard was from a German-born woman who married a US serviceman and learned most of her English in Midland TX. I'll never forget her bringing a tray of goodies around and saying "Vich vun y'all vant?"
But I guarantee, it will cause at situation where a desperate person who viewed their only option as evading, who is now sitting in an otherwise dead vehicle, to open fire and cause a deadly force situation from the police.
So, ummm, what will the same guy do at the end of a high-speed chase where police cars are screeching to a stop all around him and the officers don't have the luxury of making a cautious approach?
Nature has little trouble doing this. There are, for example, swarms of tiny luminescent fish in the Caribbean, which I've seen on a Windjammer cruise.
The captain, commenting on them, pointed out that the ship's toilets were seawater-flushed, "So you can put your head right down in the bowl and flush. It's an AMAZING sight."
Look at it this way: suppose your state legislator offered a bill to amend the criminal code, authorizing judges to sentence rapists to "five to ten years of regular forcible sodomization, such punishment to be applied not less than two nor more than five times per week." Would you support that?
Last time I was at the Cape, tour guides there were still telling people with a straight face that the local birds, snakes and alligators had all learned to tell when a big launch was coming up and would clear out in time.
In particular, I've been told that quite a few people were in the habit of listening to the opening of the Edgar Bergen & Charlie McCarthy show, during which they did a comedy dialogue shtick (with W.C. Fields occasionally dropping in), then switching over to Welles's show.
And anyone who thinks the public would have to be pretty stupid to fall for the "alien invasion" should remember that this took place in a time when one of the most popular entertainment shows in the country was a ventriloquist performing on the radio.
Around here, only a few of the carts have the device...most of them just have the warning sign. And on the ones that do have it, the special wheel snaps into the frame just like the others do, so anyone who wants a cart has to steal two.
But few people want the carts to use as carts anyway...ripping them off is generally just an adolescent machismo ritual.
There is a phenomenon visually very similar to heiligenschein that in no way depends on water. The easiest way to see it is to fly at low altitude over a vegetated area in close company with one or more other aircraft -- which is not very easy for most folks. But if you can contrive to do this, you will find that the shadow of your aircraft -- and only yours -- has a glow around it.
The mechanism: Every pebble and blade of grass casts a shadow, and in general you see a mixture of sunlit and shaded areas. But at the antisolar point, everything you see is sunlit. The smaller your aircraft, the brighter the glow.
Most of the people who have seen this are sailplane pilots who often circle in gaggles within the narrow radius of a thermal, for precisely the same reason that buzzards do. It can actually be useful in avoiding collisions.
...I ported some programs from Atari and Apple II to C64 for (the other) Scott Adams's Adventure International. I thought it was an absurd piece of crap. The sprite and sound features were pretty good for its time, but the (giggle) OS was pathetic. You couldn't load a disk-based program without issuing a BASIC command, the disk drives were unbelievably slow (about 1/4 the speed of the older Atari drives which were slow compared to the older Apple drives), and even the cursor-control routines didn't work: if you moved the cursor during an ON blink, it would leave a ghost of itself, so I had to write my own cursor handler.
If you had two disk drives, you couldn't stack one atop the other lest they both overheat and pop errors, and you were lucky if they lasted six months. The video output was so cheap you were restricted to a very narrow range of color combinations, lest the characters wash one another out. The available contrast range was from MILKY to OFF.
One of my ports was a text-with-pictures adventure called Labyrinth of Crete. I had to create picture files with fill textures custom-designed around RLL compression to keep the load times under five minutes.
Editing and assembling code on the C64 was pretty much out of the question; I wrote and assembled it on an Atari and then null-modem'ed it over. The last C64 disk drive died about the same time as Scott's business.
And yet, for about a year, it brought in more cash than my day job. Go figure.
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As I remember, the effect of the laser burn was to "freeze" some bytes in one sector...you could read them but not change them. The test was to write it with all zeroes, read and compare with all zeroes, write with all ones, and compare with all ones. The burn would always create a compare error somewhere in the sequence.
rj
I remember a primitive attempt at this in the copy protection routine for dBase III way back when the DMCA was but an industry wet dream. This was the ProLok Disk, the one with the laser burn.
There was a section of code hidden by about forty layers of byte-by-byte XORing against bytes looked up in a table. At each level, it would intercept the Debug and Single Step interrupts, XOR the next layer, and jump into it. In those floppy-only days, it had to be reverse engineered a layer at a time, each step producing a disk with one less layer. Approximately the 40th disk had the actual copy-test code...which turned out to be pirated code!
This was also before BIOS shadowing in RAM, and the BIOS executed straight from ROM. The test for the laser burn required hooking into it, which of course they couldn't do in ROM. Instead of working out their own shadowing routine they copied some 700 bytes of the IBM Fixed Disk BIOS, inserted their hooks, and then made a weaselly attempt to cover their tracks by interchanging logical-shift with arithmetic-shift instructions wherever it was guaranteed that nothing would go through the carry bit.
And all that meshugass was there only to hide the publisher's own piracy...the copycrack consisted of a two-byte change elsewhere on the disk.
rj
That idea was mentioned, at least at the brainstorming level, in the Moon Race days. There was a proposal to send a crew one-way with lots of supplies and a promise to follow up with a return vehicle a year or so later.
It was also suggested that they should be armed in case the Russians arrived and tried to take their supplies.
rj
And a film you don't often see on the tube without some editing. A frequently-appearing character in it is the squadron commander's black Labrador, whose name didn't cause any problem in a wartime British film but would not go over well on USAn TV today..
rj
-Hey, nice pecker stretcher, and those pictures of the guy with the goat are really cool. Where'd you get 'em?
-I ordered them from a spam ad.
-You PIG!!!
rj
I had the pleasure of working around some of the Paperclip crowd when I did my MS thesis at Wright-Patterson AFB in 1964: Hans von Ohain, who had raced one-on-one with Frank Whittle to get the first jet engines flying, was the head of the Aerospace Research Lab there and my thesis advisor was a lower-level guy named Erich Soehngen. He had the ultimate excuse for not having a Ph.D: The Eighth Air Force dropped one on his dissertation in 1944.
rj
Most charming accent I ever heard was from a German-born woman who married a US serviceman and learned most of her English in Midland TX. I'll never forget her bringing a tray of goodies around and saying "Vich vun y'all vant?"
rj
A chap named Moulton "Molt" Taylor put it on the market in 1949. You didn't buy one.
rj
Many of the better auto-body shops hereabouts flatly will not hire a painter who has ever worked for Earl Scheib.
rj
The Beagle has landed. Poorly. rj
So, ummm, what will the same guy do at the end of a high-speed chase where police cars are screeching to a stop all around him and the officers don't have the luxury of making a cautious approach?
rj
..or explain to the family of a suicide bomber why he surrendered without firing a shot.
rj
Nature has little trouble doing this. There are, for example, swarms of tiny luminescent fish in the Caribbean, which I've seen on a Windjammer cruise.
The captain, commenting on them, pointed out that the ship's toilets were seawater-flushed, "So you can put your head right down in the bowl and flush. It's an AMAZING sight."
rj
Didn't Tutankhamen settle that?
rj
Look at it this way: suppose your state legislator offered a bill to amend the criminal code, authorizing judges to sentence rapists to "five to ten years of regular forcible sodomization, such punishment to be applied not less than two nor more than five times per week." Would you support that?
rj
Ummm, so, what ARE your contenders for the most dramatic periods of solar activity?
rj
Yabbut a lot of that sound gets reflected up from the ground before the bird starts to move.
rj
Last time I was at the Cape, tour guides there were still telling people with a straight face that the local birds, snakes and alligators had all learned to tell when a big launch was coming up and would clear out in time.
rj
Yes, and the crews had quite a bit of metal between them and the engines. rj
In particular, I've been told that quite a few people were in the habit of listening to the opening of the Edgar Bergen & Charlie McCarthy show, during which they did a comedy dialogue shtick (with W.C. Fields occasionally dropping in), then switching over to Welles's show.
And anyone who thinks the public would have to be pretty stupid to fall for the "alien invasion" should remember that this took place in a time when one of the most popular entertainment shows in the country was a ventriloquist performing on the radio.
rj
Ummm...were you under the impression it was flying supersonic five miles from the runway?
rj
But few people want the carts to use as carts anyway...ripping them off is generally just an adolescent machismo ritual.
rj
There isn't much point in stealing a common, ordinary cart either...but the stream that flows through my neighborhood greenspace is full of them.
rj
There is a phenomenon visually very similar to heiligenschein that in no way depends on water. The easiest way to see it is to fly at low altitude over a vegetated area in close company with one or more other aircraft -- which is not very easy for most folks. But if you can contrive to do this, you will find that the shadow of your aircraft -- and only yours -- has a glow around it.
The mechanism: Every pebble and blade of grass casts a shadow, and in general you see a mixture of sunlit and shaded areas. But at the antisolar point, everything you see is sunlit. The smaller your aircraft, the brighter the glow.
Most of the people who have seen this are sailplane pilots who often circle in gaggles within the narrow radius of a thermal, for precisely the same reason that buzzards do. It can actually be useful in avoiding collisions.
rj
...I ported some programs from Atari and Apple II to C64 for (the other) Scott Adams's Adventure International. I thought it was an absurd piece of crap. The sprite and sound features were pretty good for its time, but the (giggle) OS was pathetic. You couldn't load a disk-based program without issuing a BASIC command, the disk drives were unbelievably slow (about 1/4 the speed of the older Atari drives which were slow compared to the older Apple drives), and even the cursor-control routines didn't work: if you moved the cursor during an ON blink, it would leave a ghost of itself, so I had to write my own cursor handler.
If you had two disk drives, you couldn't stack one atop the other lest they both overheat and pop errors, and you were lucky if they lasted six months. The video output was so cheap you were restricted to a very narrow range of color combinations, lest the characters wash one another out. The available contrast range was from MILKY to OFF.
One of my ports was a text-with-pictures adventure called Labyrinth of Crete. I had to create picture files with fill textures custom-designed around RLL compression to keep the load times under five minutes.
Editing and assembling code on the C64 was pretty much out of the question; I wrote and assembled it on an Atari and then null-modem'ed it over. The last C64 disk drive died about the same time as Scott's business.
And yet, for about a year, it brought in more cash than my day job. Go figure.
rj