Re: Speed difference between disk formatted on PC and MSX
shevek wrote:
I was saying that the analogy with gaps was not correct. A gap
contains bytes just like sectors do, altough the values of the bytes are
not used to store data. Making gaps bigger doesn't change the amount
of magnetic disk surface reserved for one byte.
The gaps will be larger, but sectors will be larger as well. The whole
track is scaled. It makes sense to me, anyway.
Yes, on outer tracks all bits (sectors, gaps, headers) span more disk
surface than on inner tracks. I'll have to be very explicit to make
sure no-one misunderstands me...
What the threat was about is that when you format a disk, the
formatting program decides the number of bytes per gap. MSX diskROMs
seem to use more bytes per gap than PCs. Then we started wondering
what difference this makes.
You suggested reliability would improve because more disk surface is
used when gaps are larger, but that's not true as larger gaps only
means more bytes per gap, this doesn't improve the readability of
bytes inside a sector.
/Use_gcc_to_compile/
/*xxoxo o*/ intmain()/* */{int i,j,s=1, k,z ,c[
]={1,4 ,7,4,3,4,6,4 ,1,1,1 ,2,
3,3,3, 4},v[9];;for (i=0;i ++
9!k;s=-s){k=0;;scanf("%d" ,z) ;v[z]=s ;for(j
=0; j8 ;++j){ z=v[c[j]];k|=z ==v
[c[ j]- c[j+8] ](v[c [j]+c[ j+8
]]==zz); ;}}printf(" %d won\n",- s*k );}
/***Tic-tac-toe.use_0-8_to_play/
So this is your long-awaited new signature?
Bye,
Maarten
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put
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Re: Speed difference between disk formatted on PC and MSX
On Tue, 20 Apr 1999 [EMAIL PROTECTED] wrote:
What the threat was about is that when you format a disk, the
formatting program decides the number of bytes per gap. MSX diskROMs
seem to use more bytes per gap than PCs. Then we started wondering
what difference this makes.
Indeed. But I didn't reply to that. Never mind.
So this is your long-awaited new signature?
Indeed. Do you like it?
/Use_gcc_to_compile/
/*xxoxo o*/ intmain()/* */{int i,j,s=1, k,z ,c[
]={1,4 ,7,4,3,4,6,4 ,1,1,1 ,2,
3,3,3, 4},v[9];;for (i=0;i ++
9!k;s=-s){k=0;;scanf("%d" ,z) ;v[z]=s ;for(j
=0; j8 ;++j){ z=v[c[j]];k|=z ==v
[c[ j]- c[j+8] ](v[c [j]+c[ j+8
]]==zz); ;}}printf(" %d won\n",- s*k );}
/***Tic-tac-toe.use_0-8_to_play/
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put
in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the
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Re: Speed difference between disk formatted on PC and MSX
schevec written: It was not my mailer, I typed that sentence myself. I thought all names start with capitals, simply because that is the convention for names. Why do you want yours with a lower case first letter? The name shevek comes from a book (the dispossessed by Ursula LeGuin). It is the name of a character there. It's about an anarchistic (but organised) planet. Because I would like to live in such a world and because he's pretty much like me anyway, I chose it to be my nickname. They have a different language and the names are generated by computer. My own interpretation is that the silly capital/non-capital-thing was removed as well, since the language was designed by people. There is someone else on the net I know of called Shevek. He's a coder, too. Like this there still is a difference between us (I'm sure there are more differences :) ) Anyway, this is pretty off topic, so I'll start my real reply now ;) Do you want to know where Grauw (with capital!) comes from??? :) ~Grauw MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
On Sat, 17 Apr 1999, jam wrote: AW I agree on this explanation. You can doublecheck this theory by AW analyzing the track with some kind of track analysis tool. If I AW remember correctly, there exists some kind of japanese copy program AW which can analyze the track for you. Though, I do not remember its AW name. I think you're speaking about Formula :) It's one of the best copying program for MSX. It uses low-level access to the disk controller, so it only works with some controllers. BTW, it works on my Turbo-R perfectly. Where can I download it? Is it commercial or free software? Greetings from Brazil! - Marco Antonio Simon Dal Pozhttp://www.lsi.usp.br/~mdalpoz [EMAIL PROTECTED] "Apple" (c) Copyright 1767, Sir Isaac Newton /"\ \ / CAMPANHA DA FITA ASCII - CONTRA MAIL HTML X ASCII RIBBON CAMPAIGN - AGAINST HTML MAIL / \ MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
RE: Speed difference between disk formatted on PC and MSX
I think it is the same reason as putting the boot sector on the outside of the disk (the widest circle). There is more magnetic space reserved for the sector, so it will be more secure. That's not true. A bigger gap doesn't mean the bytes inside sector get more space, it only means they are surrounded by more space. Well, not quite. A diskdrive is based on CRV (or something, Constant Radial Velocity), which means the RPM's are always the same, like a record-player. The gap doesn't change if the head is at track 0 or at track 79. Thus, there IS more magnetic material passing the heads for one rotation (i.e. one track). The bitrate remains the same. Actually, this fact is used in Commodore 1541 diskdrives to get more data on the outer tracks than on the inner. CD's on the other hand use CLV (constant linear speed) which means the disc track always passes the laser at the same speed (assuming a one-speed drive). The RPM changes accordingly. The bitrate is always the same. The reason why CD's start on the inside is that there are more sizes (like single-cd), so it's easier to find the first track than to look for the edge (like your old record player) and start looking for a header (remember that lead-in groove on a record ;-) Greetz, Patrick MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
On Fri, 16 Apr 1999, Maarten ter Huurne wrote: Shevek wrote: Even mailers don't understand my name doesn't start with a capital :( I think it is the same reason as putting the boot sector on the outside of the disk (the widest circle). There is more magnetic space reserved for the sector, so it will be more secure. That's not true. A bigger gap doesn't mean the bytes inside sector get more space, it only means they are surrounded by more space. Strange. I always thought of it as very logical that cd's have their first track on the inside:safer against (physical) damage. and disks have it on the outside: safer against magnetic damage. But the last argument doesn't seem to work, then. In that case I would expect it to be on the inside of the disk against physical damage, like on a cd... Does anyone know the reason for putting it on the outside? Or did they just choose something? Bye, shevek My signature will change soon. --- Visit the internet summercamp via http://polypc47.chem.rug.nl:5002 MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
Adriano Camargo Rodrigues da Cunha wrote: But with a small gap do I gain more disk space, don't I? In theory, yes. You can fit 10 sectors into a track if you make the gaps small enough. But unless you're doing direct disk I/O, you can't access the 10th sector in a track. The diskROM always uses 9 sectors per track. Although a format with 8 sector per track also exists, maybe some old MSX diskROMs also support that. Shevek wrote: I think it is the same reason as putting the boot sector on the outside of the disk (the widest circle). There is more magnetic space reserved for the sector, so it will be more secure. That's not true. A bigger gap doesn't mean the bytes inside sector get more space, it only means they are surrounded by more space. Does anyone know what the function of the gaps is in the first place? Is it only for giving the computer time to prepare for the next sector? Or does it have an impact on data safety as well? Bye, Maarten MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
At 04:49 PM 4/15/99 MET, you wrote: BTW, speaking of disks on PC/MSX... A disk formatted on MSX usually has a name (of the computer/diskrom) in sector 0. After a disk has been put in a PC, this name is overwritten by something like IHC). Does anyone know why the PC overwrites the name? The same thing happened to me right this morning! I was helping Rieks translate some difficult parts of the intro of Firehawk. When I tested my patch program I was going to send to him, the patched disk refused to work. To find the error, I made a DSK image of the patched disk and compared it to a non-patched disk. Apart from the changes the patch should have made, the OEM ID had changed. I had no idea how this happened and it didn't occur again when I replayed all my actions and logged the results. I don't think all PCs do this, it probably depends on the operating system. I'm running Win95 here. I think it's very dangerous behaviour, because a lot of multiple disk sector-based games use the OEM ID to identify which disk is which. Does anyone know how to turn it off? There may be some kind of obscure registry setting affecting this. Bye, Maarten MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
RE: Speed difference between disk formatted on PC and MSX
You can access the 10th sector without directly accessing the controller. The diskrom splits the logical sector number into three parts: - side number - track number - sector number (normally 1 - 9) This division routine (BC = BC/DE, remainder HL) calls a hook (F27F) at the end of its calculation. All that has to be done is set HL to the appropiate value, 10 for example and this 10 will be used to address sector number 10 within a certain track. But it could also be 240, it is just a value to identify the sector number on the disk. Normally these sector numbers range from 1 - 9, but they can also be something like 101, 102, 103, 104, 105 - 109. The diskrom normally only searches for 1 - 9, which is the remainder value + 1. But by changing the value returned by this particular hook you can change all that. Rests only to be able to write a different track than the normal one. I have seen this technique being used in several copy protection programs. To test this on a MSX/MSX2, write the following two instructions at address F27F: LD (9000H),HL RET And view the value written at 9000h-9001h after reading a logical sector in basic. Have fun. Frits -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Maarten ter Huurne Sent: Friday, April 16, 1999 4:34 PM To: [EMAIL PROTECTED] Subject: Re: Speed difference between disk formatted on PC and MSX Adriano Camargo Rodrigues da Cunha wrote: But with a small gap do I gain more disk space, don't I? In theory, yes. You can fit 10 sectors into a track if you make the gaps small enough. But unless you're doing direct disk I/O, you can't access the 10th sector in a track. The diskROM always uses 9 sectors per track. Although a format with 8 sector per track also exists, maybe some old MSX diskROMs also support that. Shevek wrote: I think it is the same reason as putting the boot sector on the outside of the disk (the widest circle). There is more magnetic space reserved for the sector, so it will be more secure. That's not true. A bigger gap doesn't mean the bytes inside sector get more space, it only means they are surrounded by more space. Does anyone know what the function of the gaps is in the first place? Is it only for giving the computer time to prepare for the next sector? Or does it have an impact on data safety as well? Bye, Maarten MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/) MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
Hi When I DOSSCAN a DD disk formatted on PC, I get about 12 or 13 kB/s, but when I DOSSCAN a DD disk formatted on my MSX, I get 16 or 17 kB/s! Can anyone explain me the difference, exactly? Thanks! Disks are used not very often on the PC so the first part they (the dealers) cut in on are the floppydrives. The most PC-drives are just very cheap models. ~Grauw MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
On Thu, 15 Apr 1999, Adriano Camargo Rodrigues da Cunha wrote: Erik, when the gap size is too small (and he is on a pc formatted disk) he sometimes have to make a complete rotation for the next sector But with a small gap do I gain more disk space, don't I? If not, what is the advantage of having a small gap if, in some cases (as this one), it slow down the reading speed of the disk? I think it is the same reason as putting the boot sector on the outside of the disk (the widest circle). There is more magnetic space reserved for the sector, so it will be more secure. Manuel: Interleaving is putting the sectors of a disk in a strange order, and not linear. This is good for computers that take long to write the data to the memory. If the gap is passed already, it is not in the sector it needs, so it doesn't need to wait a full cycle. This is indeed part of the standard, so all MS(X)-DOS disks will work fine with interleaved settings. Bye, shevek My signature will change soon. --- Visit the internet summercamp via http://polypc47.chem.rug.nl:5002 MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
shevek schreef: I know of a program called formula that can do this indeed. It uses direct fdc access, so it does not work on eg the philips nms8245. It works fine on the nms8250, though. Bye, shevek My signature will change soon. --- there is someting called FDD test , it's a cartridge made by MT for testing philips computers. I have seen a pre relaese version of this software witch was also able to read a raw track into memory. with a memory monitor you could studie the data. all philips MSX's work on the same fdd principle so if software works on the 8250 it should also work on the 8245. the sony hardware is also almost the same (needs 1 bit more to set) erik -- MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
The PC has a HD floppy drive and it just costs time to read from DD floppies instead of HD floppies... it has to do al sorts of conversion routines etc.etc. The MSX however is optimized to work with the DD disks.. hence the difference Are the disks not both read on MSX? If the PC has to do conversion routines, it has to do it only while writing the disks. But maybe it IS the HD-drive that does it, because the signals of the HD-drive are weaker and the MSX has to try harder to read a sector ??? BTW, speaking of disks on PC/MSX... A disk formatted on MSX usually has a name (of the computer/diskrom) in sector 0. After a disk has been put in a PC, this name is overwritten by something like IHC). Does anyone know why the PC overwrites the name? See Loy. MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
The PC has a HD floppy drive and it just costs time to read from DD floppies instead of HD floppies... it has to do al sorts of conversion routines etc.etc. The MSX however is optimized to work with the DD disks.. hence the difference Are the disks not both read on MSX? If the PC has to do conversion Yes, I'm talking about running DOSSCAN on MSX, with a disk formatted on MSX and a disk formatted on PC... So what Antal says has nothing to do with it. routines, it has to do it only while writing the disks. But maybe it IS the HD-drive that does it, because the signals of the HD-drive are weaker and the MSX has to try harder to read a sector ??? Hmmm... Sounds unlikely. Grtjs, Manuel PS: MSX 4 EVER! (Questions? See: http://www.faq.msxnet.org/) PPS: Visit my homepage at http://www.sci.kun.nl/marie/home/manuelbi/ MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
] Is the track formatted with an other interleaving setting ? ] ] 1 2 3 4 5 6 7 8 9 ] ] or ] ] 1 3 5 7 9 2 4 6 8 ] ] Or the PC is optimized for an other interleaving setting than the MSX is. I agree on this explanation. You can doublecheck this theory by analyzing the track with some kind of track analysis tool. If I remember correctly, there exists some kind of japanese copy program which can analyze the track for you. Though, I do not remember its name. Kind regards, Alex Wulms -- Alex Wulms/XelaSoft - MSX of anders NIX - Linux 4 ever See my homepage for info on the *** XSA *** format http://www.inter.nl.net/users/A.P.Wulms MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
] Is the track formatted with an other interleaving setting ? ] ] 1 2 3 4 5 6 7 8 9 ] ] or ] ] 1 3 5 7 9 2 4 6 8 ] ] Or the PC is optimized for an other interleaving setting than the MSX is. I agree on this explanation. You can doublecheck this theory by analyzing the track with some kind of track analysis tool. If I remember correctly, there exists some kind of japanese copy program which can analyze the track for you. Though, I do not remember its name. Ok, this may sound stooopid, but: what IS an interleaving setting? And why is it different? And why is it compatible? (Part of a standard?) Grtjs, Manuel PS: MSX 4 EVER! (Questions? See: http://www.faq.msxnet.org/) PPS: Visit my homepage at http://www.sci.kun.nl/marie/home/manuelbi/ MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
well , it's not that. in the past i have done some checking on this strange behavior (when i was writing the supercop software) and MSX and PC do not use interleaving the main difference is the gap size. this is the space between 2 sectors msx gap size is bigger so the computer has more time to transport data after reading a sector. when the gap size is too small (and he is on a pc formatted disk) he sometimes have to make a complete rotation for the next sector erik de boer Frits schreef: Is the track formatted with an other interleaving setting ? 1 2 3 4 5 6 7 8 9 or 1 3 5 7 9 2 4 6 8 Or the PC is optimized for an other interleaving setting than the MSX is. Manuel Bilderbeek wrote: Hi When I DOSSCAN a DD disk formatted on PC, I get about 12 or 13 kB/s, but when I DOSSCAN a DD disk formatted on my MSX, I get 16 or 17 kB/s! Can anyone explain me the difference, exactly? Thanks! Grtjs, Manuel PS: MSX 4 EVER! (Questions? See: http://www.faq.msxnet.org/) PPS: Visit my homepage at http://www.sci.kun.nl/marie/home/manuelbi/ MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/) MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/) MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
Erik, when the gap size is too small (and he is on a pc formatted disk) he sometimes have to make a complete rotation for the next sector But with a small gap do I gain more disk space, don't I? If not, what is the advantage of having a small gap if, in some cases (as this one), it slow down the reading speed of the disk? Adriano Camargo Rodrigues da Cunha ([EMAIL PROTECTED]) Engenharia de Computacao - UNICAMP http://www.adrpage.cjb.net MSX-TR:I have one.And you? *** NEW URL! AdrianPage now is at http://www.adrpage.cjb.net *** * Windows98: the second plug-and-PRAY system. * MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
Re: Speed difference between disk formatted on PC and MSX
I don't know why pc uses a small gap , the only reason i can think of is that the start and end gap (the area in witch the index pulse must appear) will be bigger so you can use diskdrives with a wider tolerance btw. (there is so many space on a track you can put 10 sectors on it with a very small gap) erik Adriano Camargo Rodrigues da Cunha schreef: Erik, when the gap size is too small (and he is on a pc formatted disk) he sometimes have to make a complete rotation for the next sector But with a small gap do I gain more disk space, don't I? If not, what is the advantage of having a small gap if, in some cases (as this one), it slow down the reading speed of the disk? Adriano Camargo Rodrigues da Cunha ([EMAIL PROTECTED]) Engenharia de Computacao - UNICAMP http://www.adrpage.cjb.net MSX-TR:I have one.And you? *** NEW URL! AdrianPage now is at http://www.adrpage.cjb.net *** * Windows98: the second plug-and-PRAY system. * MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/) MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
