I don't think it was done that way though. That's what I initially though (what you wrote, which would be dead easy), and I'm not sure why it wasn't done like this. The actual disk seems to have the data interwoven so you have alternating tracks of IBM and C64 data. Either that or I'm misunderstanding what Trixter wrote...
My inital post wasn't really specific enough in it's terminolgy. It was almost painful to bang out as I was dealing with some pretty old memories!:p
When I said "side" I should have really said something like "from the view of the (C64/IBM)". I wasn't really talking about sides of the disk, but the 'view' you take when working on one system or the other.
For the actual physical layout, it looks like one side of the floppy itself was used in it's entirity for the IBM data. The other side of the floppy had interwoven C64 and IBM data. On the hybrid side the 'free block table' (there is an "proper" name for this I cannot remember) was filled so all sectors were marked as in-use, the file marked as no-delete, etc was done.
Also - the disks themselves had those little notches that had to be present (physical write-protection) else you couldn't modify the contents at all anyway. This was probably the case for this diskette (or would have been if it went into production).
GCR - Thank you! That's the acronym I meant! I've been brainwashed by the PC world it seems, whenever I think:bit level media encoding" the letters "MFM" immediately jumps to mind these days...:-(
As for getting them to play nice with each other - just set up the directory so that the C64 has no business ever "looking at" a IBM section (and vica versa). In this case, the entries (files) in track 18 just need to point to only the "good" C64 blocks. The C64/1541 never touched (well,read) any block unless it was in a files chained pointer list. Also, I believe (bit fuzzy here) you have a "free block table" so you could have even marked off all the other areas so you could write to the IBM portions. Well, at least not through the normal SAVE command anyway (ie- mark the disk as full, 0 blocks free).
Actually, I butchered a few terms in my post most likely. My brain nearly froze trying to remember the different terminologies (block/sector etc) from back in the day! I haven't done low level disk stuff on any platform since the late 80's. I think I got the meaning across OK hopefully.
Also- I think the encoding was more likely at a lower level then even what you'd consider "track basis". I don't really know the IBM side so I don't know if the interleave would have been same, etc. Again I can visualize what I mean here, but I can't remember the terms anymore for what the "lead in", "gap" etc in the low level bit encoding was called. I think I've blocked out all the programming knowledge I used to have regarding getting the 1541 to do it's voodoo (*shudder*, assembly from hell!).
Oops- forgot to add, of course if you didn't do copy-protection at the disk level (as I'm guessing the case is here, hard enough to make it dual format!), this wasn't an issue. You just interwove the data so neither side (C64/IBM) really knew about the other, or cared really. If it wasn't linked via an entry in track 18 the C64/1541 had no business "looking" at a track/block). Not sure what the deal was on the IBM side but I'd guess simular.
That was the case for heavy-duty copy protection schemes. The idea was that you'd have a small area of the drive with a loader program in the "normal" format and track 18-0 as readable as well so you could do the directory, the rest in your own non-standard format the couldn't be read at all. You'd then do all sorts of wacky code tricks to obscute the loader program itself, but once it loaded, it could deal with the non-standard data blocks/tracks on the disk.
(wow...my first slashdot post in like 5+ years...something I actually can know stuff about! LOL)
I wanted to email Trixter this but couldn't find a contact email.
It's been now about 25 years but I still have parts of the C64 ROM's memorized. There was a time that I knew pretty much what every byte in the 64k(*) of memory was for cold without needing a reference manual. Having said that:
This wouldn't have been all that hard to do by somebody who had intimiate knowledge of *both* IBM and C64 formats I'd imagine. First, I doubt it was done 'by hand' as in a manual sector by sector copy. A program would have been written, using a slave-master 2 drive config, to stream from the source drive to the dest. drive using a list ot sectors/tracks and/or using a simple formula to calc where the tracks should go. You simply would pick areas on the C64 side that you would want reserved for the IBM side and vica versa. Knowing both IBM and C64 MFM structures would allow you to pick "safe" areas for both formats.
Oh, and the directory structure of the C64 did indeed live on track 18. All the other data blocks where chained out as a linked list from the entry in this track.
All that would have been really needed is:
#1) Format the disk for IBM and use whatever areas you need via a streamed block by block copy from Src to Dst. #2) Noting which tracks are "safe" to use on the C64, simply write a program to format track by track and write the C64 data, streaming again.
Ingenious, but really not that hard at all...
(*) Well, more like ~80k with the shadow RAM near the top of the 64k range...
They had a dev center in Vancouver in the past, it was called Microsoft-WGC (Work Group Canada) and I worked there. They shut it down in 1996 in order to consolidate everyone to Redmond as it was too difficult to communicate they said. They had 100+ employees with at least 60-70% of that being Devs. I remember some bad feelings about how they handled the closesure of MS-WGC.
Assuming the store is open for 12 hours a day, that means that they have to pay for $600 in payroll. Assume $10.00 per hour (in paycheck, plus employer-side social security taxes, plus benefits packages), and you are spending $6K per day in payroll. With 100% markup, your $20K in sales cost you $10K in merchandise, so now you're down to $4K margin on the day
HUH? $6,000 in payroll? Is this some kind of new math?
15 employees X 12 hours x 10 hours = $1800 not $6000. That margin just went up to $8200!
Huh??? Over the hill and can't code at 30???
on
Coder or Architect?
·
· Score: 1
You can't be serious. I feel that at 28 my skills are better than they've ever been! And I've been doing this since I was 8-10 or so. Sigh...good old trusty c64 (still have most of the memory map memorized after all these years!:) ).
There are many points I can make to argue that you get better as you get older. However, I'd think this was obvious. Do you really mean "30 and over the hill??" I know at 50+ your memory and stuff might start going...but 30???
Truely curious here. I never post to slashdot and this post actually got me to come out of lurkmode...
Ok, since I spent about $200 US a year ago to fix the exact same problem I thought I'd share what I learned.
#1) You need to fix ALL noise sources inside your computer. Throwing in a new CPU fan no matter how quite will not really help much. You need to get a quieter CPU FAN (the Molex radical fin someone mentioned is what I used), a new power supply with a quieter fan, AND, MOST IMPORTANT, you need to quiet down your hard disk drive(s).
Check out www.quietpc.com - I got all 3 products I needed (CPU FAN, Power Supply, and HD noise suppressors) from them.
Lastly, if running a CPU that takes a lot of juice, you need to turn down the CPU VCore to cut back on some of the juice. My Athlon 1000MHZ runs 100% stable at 1.40V. This is important because most "quiet" PS units have variable speed fans. I can hear the difference between 1.75V and 1.40V.
Also- Be sure to try and lower the power consumption of your PC as much as possible. Example- An external modem with seperate PSU will not tax your internal PSU as much hence that variable speed fan will spin slower.
Lastly, you can take more drastic measures like cutting voltage to the fans and then underclocking your CPU (say a 1.4GHZ CPU down to 1.0GHZ) to generate less heat.
Someone on/. even mentioned a while back that they got a DEAD SILENT PC by disconnecting all fans and then just running there 1G PIII at 500MHZ or so since the CPU barely gets warm....
For all those mourning magic, there is a better solution! Adopt a game that's not being produced anymore. For example, me and about 6-8 other people now play Middle Earth: The Wizards regularly. You can pick up cards on Ebay dirt cheap, and it's the closest thing to real gaming for any card game out there.
Best of all, since it's no longer produced you don't have to worry about the "card race" that exists in games like MTG. With about 2000 cards across all sets, it will be a long time before you get bored.
Note: METW is made by I.C.E (RIP), so except a level of complexity unheard of in card games.
WTF? Does this mean my pounding 1200 watt car stereo system actually has practicle use? So by listening to music with lots of low frequency harmonics at low volumes I'm making my bones stronger?
RIGHT ON!!! I can't wait to use that one next time I'm pulled over for a noise ordinance violation by the cops!
"But officer, my doctor said I've got brittle bones!"
People thought J. Dalhmer's posts about eating people to usenet were a joke too. Whoops.
Would it really have hurt them to put a "this is a parody" disclaimer at the bottom of the site?
I first saw the site when www.memepool.com linked to it a while back. I wasn't sure if it was a parody or not, and I'm pretty jaded. I guess it all boils down to responsibility.
If I had a "how to kill your neighbours" site and posted (faked) pictures, do you think I should get investigated? Maybe a we should consider people reporting crimes to 911 as just 'pranks' to?
Were do you draw the line?
Ted
Re:well why don't you...
on
EULA In Games
·
· Score: 1
Interesting...In theory, one could write a piece of code that does all the necessary file copies. Then all that is really left is to add keys to the registry, no? Take a virgin Windows install, make a copy of the reg, install Office. Write some code to do a diff. between the before/after, write a little installer that adds the extra bits. Not all that hard, in fact I wrote something like this when I worked for the Federal Gov't a few years ago. They didn't want to install an entire app onto a machine (this is in the day of 100 *MEG* HD's) so they'd run the files off the server and add the reg. keys to the client tricking it into running...
Ebay Insurance (3rd party) covers all transactions except for the first $50. So, if you spend $20,000 on an item, have the receipt proving you paid, you get $19,950 back. I assume a collection agency/etc goes after the deadbeat seller...
(I actually had to use there insurance once when I got stiffed on a AMD K6-450 I "won")
Slashdot Mirror
Slashdot quote at the bottom of this discussion as I type this:
"I'll show you MY telex number if you show me YOURS ..."
Better not say that at the next conference you attend!
LOL - Yeah, I forgot about that one! That was the first one since 2001 though. We need more C64 threads, then I'll be able to post more! :-)
Ted
I don't think it was done that way though. That's what I initially though (what you wrote, which would be dead easy), and I'm not sure why it wasn't done like this. The actual disk seems to have the data interwoven so you have alternating tracks of IBM and C64 data. Either that or I'm misunderstanding what Trixter wrote...
Ted
My inital post wasn't really specific enough in it's terminolgy. It was almost painful to bang out as I was dealing with some pretty old memories! :p
When I said "side" I should have really said something like "from the view of the (C64/IBM)". I wasn't really talking about sides of the disk, but the 'view' you take when working on one system or the other.
For the actual physical layout, it looks like one side of the floppy itself was used in it's entirity for the IBM data. The other side of the floppy had interwoven C64 and IBM data. On the hybrid side the 'free block table' (there is an "proper" name for this I cannot remember) was filled so all sectors were marked as in-use, the file marked as no-delete, etc was done.
Also - the disks themselves had those little notches that had to be present (physical write-protection) else you couldn't modify the contents at all anyway. This was probably the case for this diskette (or would have been if it went into production).
Ted
GCR - Thank you! That's the acronym I meant! I've been brainwashed by the PC world it seems, whenever I think :bit level media encoding" the letters "MFM" immediately jumps to mind these days...:-(
As for getting them to play nice with each other - just set up the directory so that the C64 has no business ever "looking at" a IBM section (and vica versa). In this case, the entries (files) in track 18 just need to point to only the "good" C64 blocks. The C64/1541 never touched (well,read) any block unless it was in a files chained pointer list. Also, I believe (bit fuzzy here) you have a "free block table" so you could have even marked off all the other areas so you could write to the IBM portions. Well, at least not through the normal SAVE command anyway (ie- mark the disk as full, 0 blocks free).
Ted
I could have sworn I saw all the bits on my LCD all shift over about 0.25" for a second, then go to normal as read that! LOL
Ted
Actually, I butchered a few terms in my post most likely. My brain nearly froze trying to remember the different terminologies (block/sector etc) from back in the day! I haven't done low level disk stuff on any platform since the late 80's. I think I got the meaning across OK hopefully.
Also- I think the encoding was more likely at a lower level then even what you'd consider "track basis". I don't really know the IBM side so I don't know if the interleave would have been same, etc. Again I can visualize what I mean here, but I can't remember the terms anymore for what the "lead in", "gap" etc in the low level bit encoding was called. I think I've blocked out all the programming knowledge I used to have regarding getting the 1541 to do it's voodoo (*shudder*, assembly from hell!).
Ted
Oops- forgot to add, of course if you didn't do copy-protection at the disk level (as I'm guessing the case is here, hard enough to make it dual format!), this wasn't an issue. You just interwove the data so neither side (C64/IBM) really knew about the other, or cared really. If it wasn't linked via an entry in track 18 the C64/1541 had no business "looking" at a track/block). Not sure what the deal was on the IBM side but I'd guess simular.
Ted
That was the case for heavy-duty copy protection schemes. The idea was that you'd have a small area of the drive with a loader program in the "normal" format and track 18-0 as readable as well so you could do the directory, the rest in your own non-standard format the couldn't be read at all. You'd then do all sorts of wacky code tricks to obscute the loader program itself, but once it loaded, it could deal with the non-standard data blocks/tracks on the disk.
Ted
(wow...my first slashdot post in like 5+ years...something I actually can know stuff about! LOL)
I wanted to email Trixter this but couldn't find a contact email.
It's been now about 25 years but I still have parts of the C64 ROM's memorized. There was a time that I knew pretty much what every byte in the 64k(*) of memory was for cold without needing a reference manual. Having said that:
This wouldn't have been all that hard to do by somebody who had intimiate knowledge of *both* IBM and C64 formats I'd imagine. First, I doubt it was done 'by hand' as in a manual sector by sector copy. A program would have been written, using a slave-master 2 drive config, to stream from the source drive to the dest. drive using a list ot sectors/tracks and/or using a simple formula to calc where the tracks should go. You simply would pick areas on the C64 side that you would want reserved for the IBM side and vica versa. Knowing both IBM and C64 MFM structures would allow you to pick "safe" areas for both formats.
Oh, and the directory structure of the C64 did indeed live on track 18. All the other data blocks where chained out as a linked list from the entry in this track.
All that would have been really needed is:
#1) Format the disk for IBM and use whatever areas you need via a streamed block by block copy from Src to Dst.
#2) Noting which tracks are "safe" to use on the C64, simply write a program to format track by track and write the C64 data, streaming again.
Ingenious, but really not that hard at all...
(*) Well, more like ~80k with the shadow RAM near the top of the 64k range...
Ted
They had a dev center in Vancouver in the past, it was called Microsoft-WGC (Work Group Canada) and I worked there. They shut it down in 1996 in order to consolidate everyone to Redmond as it was too difficult to communicate they said. They had 100+ employees with at least 60-70% of that being Devs. I remember some bad feelings about how they handled the closesure of MS-WGC.
Ted
Assuming the store is open for 12 hours a day, that means that they have to pay for $600 in payroll. Assume $10.00 per hour (in paycheck, plus employer-side social security taxes, plus benefits packages), and you are spending $6K per day in payroll. With 100% markup, your $20K in sales cost you $10K in merchandise, so now you're down to $4K margin on the day
HUH? $6,000 in payroll? Is this some kind of new math?
15 employees X 12 hours x 10 hours = $1800 not $6000. That margin just went up to $8200!
You can't be serious. I feel that at 28 my skills are better than they've ever been! And I've been doing this since I was 8-10 or so. Sigh...good old trusty c64 (still have most of the memory map memorized after all these years! :) ).
There are many points I can make to argue that you get better as you get older. However, I'd think this was obvious. Do you really mean "30 and over the hill??" I know at 50+ your memory and stuff might start going...but 30???
Truely curious here. I never post to slashdot and this post actually got me to come out of lurkmode...
Ted
ARGH!!!
.ORG!
MEMEPOOL.COM, NOT
I swear that you guys DELIBERATELY made mistakes in the stories just to generate more posts!
Ok, since I spent about $200 US a year ago to fix the exact same problem I thought I'd share what I learned.
/. even mentioned a while back that they got a DEAD SILENT PC by disconnecting all fans and then just running there 1G PIII at 500MHZ or so since the CPU barely gets warm....
#1) You need to fix ALL noise sources inside your computer. Throwing in a new CPU fan no matter how quite will not really help much. You need to get a quieter CPU FAN (the Molex radical fin someone mentioned is what I used), a new power supply with a quieter fan, AND, MOST IMPORTANT, you need to quiet down your hard disk drive(s).
Check out www.quietpc.com - I got all 3 products I needed (CPU FAN, Power Supply, and HD noise suppressors) from them.
Lastly, if running a CPU that takes a lot of juice, you need to turn down the CPU VCore to cut back on some of the juice. My Athlon 1000MHZ runs 100% stable at 1.40V. This is important because most "quiet" PS units have variable speed fans. I can hear the difference between 1.75V and 1.40V.
Also- Be sure to try and lower the power consumption of your PC as much as possible. Example- An external modem with seperate PSU will not tax your internal PSU as much hence that variable speed fan will spin slower.
Lastly, you can take more drastic measures like cutting voltage to the fans and then underclocking your CPU (say a 1.4GHZ CPU down to 1.0GHZ) to generate less heat.
Someone on
Ted
For all those mourning magic, there is a better solution! Adopt a game that's not being produced anymore. For example, me and about 6-8 other people now play Middle Earth: The Wizards regularly. You can pick up cards on Ebay dirt cheap, and it's the closest thing to real gaming for any card game out there.
Best of all, since it's no longer produced you don't have to worry about the "card race" that exists in games like MTG. With about 2000 cards across all sets, it will be a long time before you get bored.
Note: METW is made by I.C.E (RIP), so except a level of complexity unheard of in card games.
Ted
"So by listening to music with lots of low frequency harmonics at low volumes..."
Whoops...make that high or loud volumes.
WTF? Does this mean my pounding 1200 watt car stereo system actually has practicle use? So by listening to music with lots of low frequency harmonics at low volumes I'm making my bones stronger?
RIGHT ON!!! I can't wait to use that one next time I'm pulled over for a noise ordinance violation by the cops!
"But officer, my doctor said I've got brittle bones!"
People thought J. Dalhmer's posts about eating people to usenet were a joke too. Whoops.
Would it really have hurt them to put a "this is a parody" disclaimer at the bottom of the site?
I first saw the site when www.memepool.com linked to it a while back. I wasn't sure if it was a parody or not, and I'm pretty jaded. I guess it all boils down to responsibility.
If I had a "how to kill your neighbours" site and posted (faked) pictures, do you think I should get investigated? Maybe a we should consider people reporting crimes to 911 as just 'pranks' to?
Were do you draw the line?
Ted
Interesting...In theory, one could write a piece of code that does all the necessary file copies. Then all that is really left is to add keys to the registry, no? Take a virgin Windows install, make a copy of the reg, install Office. Write some code to do a diff. between the before/after, write a little installer that adds the extra bits. Not all that hard, in fact I wrote something like this when I worked for the Federal Gov't a few years ago. They didn't want to install an entire app onto a machine (this is in the day of 100 *MEG* HD's) so they'd run the files off the server and add the reg. keys to the client tricking it into running...
Ebay Insurance (3rd party) covers all transactions except for the first $50. So, if you spend $20,000 on an item, have the receipt proving you paid, you get $19,950 back. I assume a collection agency/etc goes after the deadbeat seller...
(I actually had to use there insurance once when I got stiffed on a AMD K6-450 I "won")
Check it out, every high bid has been made by the same person who has zero feedback. Wonder what Ebay's policy is on this.