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Nateo

So I've been curious about this...

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... how does the Epyx Fast Load cartridge work, exactly? I mean yeah, you plug it and it makes your disks load faster, but what instructions does it give to achieve that? I mean, there's no special chips in the cart, are there?

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From http://yangluluchina.supersized.org/archives/2010/04.html

 

In 1984 Epyx released its FastLoad cartridge for the C64 which replaced some of the 1541's slow routines with its own custom code, thus allowing users to load programs at a fraction of the time (~ 1/5th). Despite being incompatible with many programs' copy protection schemes, the cartridge became so popular among grateful C64 owners (likely the most-widespread third-party enhancement for the C64 of all time) that many Commodore dealers sold the Epyx cartridge as a standard item when selling a new C64 with the 1541.

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Fascinating. So then what was it that made the 1541's routines so slow that the Fast Load fixed?

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Fascinating. So then what was it that made the 1541's routines so slow that the Fast Load fixed?

 

This is not a definitive answer.

 

Typically it's not that the old routines are slow. It's that third party developers with different programmers and a longer deadline can come up with novel solutions. Also, the original developers had to guarantee reliable access as opposed to strictly fast access.

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... how does the Epyx Fast Load cartridge work, exactly? I mean yeah, you plug it and it makes your disks load faster, but what instructions does it give to achieve that? I mean, there's no special chips in the cart, are there?

 

There aren't any special chips in the cartridge for manipulating disk speeds no, but it's possible to greatly accelerate drive-to-C64 transfer speed purely in software. In general terms, the Epyx cartridge, Action Replay, Final Cartridge and so forth persuade the C64 to route disk commands through their ROM routines rather than the ones in the Kernel, so when a BASIC LOAD command or a call to the equivalent in the Kernel happens, the cartridge fastloader can deal with it at a significantly increased speed.

 

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So then what was it that made the 1541's routines so slow that the Fast Load fixed?

Blame the Vic-20 for that.

http://www.atariage.com/forums/topic/196898-2600-vs-vic-20/page__st__50#entry2516193

 

Of course, that means that Commodore "could" have fixed them before the C64 launched, but pretty much ported the old, slower routines over..

Kind of a big oversight there..

But good for the Fast Load business.. ;-)

 

(Actually, reading that link, it's a bit more complicated than just porting over the old routines, but still... The Fast Loads show Commodore could have done it initially.)

 

desiv

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(Actually, reading that link, it's a bit more complicated than just porting over the old routines, but still... The Fast Loads show Commodore could have done it initially.)

 

Commodore also seemed to err on the side of caution too, the tape routines were slow in part because two copies of the program were saved and even when they started using third party loaders it felt like the speed had been dialed down; this is, presumably, to make sure that the widest range of alignments or decks with dirty heads could deal with their own games...

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Blame the Vic-20 for that.

http://www.atariage....50#entry2516193

 

Of course, that means that Commodore "could" have fixed them before the C64 launched, but pretty much ported the old, slower routines over..

Kind of a big oversight there..

But good for the Fast Load business.. ;-)

 

(Actually, reading that link, it's a bit more complicated than just porting over the old routines, but still... The Fast Loads show Commodore could have done it initially.)

 

desiv

 

Wow. So it was the idea that "well, we know how to program these routines better, but it's cheaper to just re-use what already works and save on the cost of research and development".

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Yep, pretty much.

Wow. So it was the idea that "well, we know how to program these routines better, but it's cheaper to just re-use what already works and save on the cost of research and development".

 

Pretty much. Commodore didn't anticipate the 64's longevity, nor did they expect to sell a lot of disk drives. So to save time and money, they reused as much code as they could to get the machine to market just as soon as memory chip prices allowed them to meet a $595 price point (and then get the price down to $299 and then $249 and $199 as quickly as possible). They figured they'd release something, then release something better in a couple of years to replace it, like the 64 replaced the VIC-20.

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