I've been using 64HDD and it works great (in fact, I've got it mounting an NFS share off a file server, so I don't even have any disk images on it locally). However, a lot of games don't work, I presume due to fast loader routines. I have an Alps-type 1541 and a 1541-II. I built an XM1541 to connect the 1541-II to my PC. I'd like to use the 1541 with my 64C, but what is the fastest way to go? Is it worth the effort to build a parallel cable and look for something like Dolphin DOS? Will JiffyDOS perform better? Are they speed loaders that replace both the computer's kernal and the drive's? Thanks!
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There are dozens of different speeders available. JiffyDOS is probably the most compatible, but requires ROM replacement in both the drive and the computer (although an EasyFlash 3 cartridge can do the computer ROM in a cartridge). It speeds up loading on normal disks by 5-6x or so. To get faster speeds (10-12x), you have to resave your files with an optimized layout.

Parallel speeders like Dolphin DOS are really fast, but somewhat difficult to find these days. Also not as compatible. Requires ROM replacement in computer, also a parallel cable, and another board in the drive for some logic, ROM, and 8k track buffer.

Kernal-only replacements are also available. Magnum-load, Turbo-DOS, ExOS. These act like speeder cartridges and upload drive code every time you issue a load command. However, they won't be rendered ineffective if a game changes the load vectors, like a cart would. ExOS is the fastest of them. I don't use these, so I can't attest to compatibility.

Cartridges are your other hardware option. Nice and easy to install. Easy to disable if you need to. Can be very very fast (ie. Action Replay). Usually they have a bunch of handy utilities on them too, like disk/file copiers, sector editors, machine code monitors, etc. Compatibility isn't as good as a ROM replacement, but if you're playing games that have been cracked to one file, they should work for 99% of what you're playing.

I've actually got an Epyx Fast Load, but since I don't have any floppies right now I haven't tried it. How does it's speed compare to JiffyDOS?

I think JiffyDOS sounds like a good combination of speed and compatibility.
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Fast Load and Jiffy are comparable in speed on regular disks. About 5x as fast as regular.

Jiffy has some other nice enhancements though, like faster directory reading, speedups for other file types (SEQ, USR, REL), speedup of saving files, faster drive head movement, and compatibility with more drives, if you have the ROMs for those drives. Fast Load only speeds up loading PRG files on a 1541 or a 1571 in 1541 mode.

Make no mistake though. Fast Load is a decent cartridge and is far better than no speeder at all!

If you wish to use a 1541, then the best speedup overall is the action replay cart. But, like other cart loaders, it can be knocked out of memory.

If you use modern devices, like UIEC/SD, though Jiffydos is the way to go. THe speedup on modern devices that natively support it is just insane, and it is also highly compatible. It is, in fact the most compatible kernel replacement, bar none.

I know of no kernel level replacement that performs out of order sector loading. Such a replacement would be comparable to action replay 6 loader.

Switchable jiffydos is probably your best bet for something that actually works with most stuff, even if you want to use your 1541.

No, I didn't do out of order sector loading. I did release a disk formatter that let you specify the sector interleave, so if you did that then out of order loading wouldn't be necessary. Of course this didn't help you with commercial programs.

On this subject, the only way to know the link to the next sector is by reading the current sector since the 1st two bytes of a sector is the sector link. So, the only way to accomplish this would be by reading/decoding just the sector header for all of the sectors (in a row) and building a sector link table. That is a great idea! I did this exact same thing with one of the SC+ utilities that 'logged' a disk. It showed the start/end block and actual length of each file by using this method. Even if it cost you one missed ordered sector pair every track, the time gained by loading sectors out of order would definitely be worth it.

Unfortunately that particular loader (exos v3) cheats.

It doesn't verify sector checksums.

A more suitable kernel replacement wouldn't cheat like that.

Good stuff! If I'd had better luck thus far with 64HDD I'd consider the PwrLoad/Kernal++ ROMs, but like I said it just doesn't work with some software. Not the author's fault, just the way it is. Or I have a bunch of faulty D64s. Have to try them in VICE I suppose. Titan, Little Computer People, Paradroid, Imp. Mission, those all work.
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The only generic speeder available in cart/ROM format that does out of order loading while verifying sector checksums is the later Action Replay (v4 Pro and newer I believe?).

You might have to lower your standards or write your own if this doesn't fit your needs.

If exos was a bit more stable, supported NTSC (it might), and was as compatible as jiffydos or at least very close, i'd consider it for my c64. But the fact that i intend to use sd2iec in the future and proper cracks suggest that jiffydos is better for me. 20x speedup is pretty darn good i'd say.

But if exos V3 is ntsc capable, i'd consider putting it and jiffy into an easyflash 3.

I patched exos to be ntsc compatible a while back. It's in the "beast system kernal" subject, which you had responded to.

I'm not sure what the stability issues are in exos. I've used it a bit and it seems to work fine, but it lacked a lot of the nice extras that other kernals had regarding the DOS wedge and such.

the other main problem is it blanks the screen, which messes with the loading process of many games, which jiffy doesn't.

Yeah, I hated that blank screen thing - its the reason why I wrote Magnum- Load.

well, why don't you write an out of order loader yourself. Those tend to load at roughly interleave 3, or so i've noticed, and take 4 revolutions to load a track. only vorpal and clones can manage it in two, and that requires custom GCR.

If you have a SuperCard (or 8K of RAM), there would be no need to worry about interleave at all, and no custom GCR is required.

true, but if you have a stock 1541 a kernel replacement comes in very handy.

I thought about writing a fast loader that used the 8k as a track cache for that purpose (and/or as a directory cache) but figured it wouldn't be too useful since few people have the 8k expansion.

To be honest I don't really see much point in using anything other than Jiffydos these days. Most of the newer devices are compatible and the rom replacements are very reasonably priced and readily available for most drives, and also it is fully documented. The only exception I can see is the need for auto boot and very few of us really need that option. Realistically how much more quickly do any of us need these machines to load?
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Does anyone know where i can get "beast system kernal" from i would like to test it.

Shane.
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It's just a clone of exos. at least the speeder is. But if your google fu fails you, i have it. send a PM