Posted By
MMS
on 2020-04-26
04:12:07
 |  Re: Overclocking PAL 264s
@gerliczer
Actually the 1541 loading was not THAT slow because of the 1541 only, but the receiving part (C64, Plus/4) could not get the data fast enough.
Just see the fastloaders, without any HW modification, there could be big differences in speed. Certainly they used different routines for loading at both sides.
This is one of the potentials Commodore lost, and really sorry they managed this way: C64 (and Plus/4) was treated to be a game computer due to the slow speed of the data storage devices, especially 1541. It is just not Now it is confirmed, that acceptable speed does NOT require hardware bit handling, just a better/more efficient communication between the computer and floppy drive, I mean an improved, backwards compatible kernel. Easyscript was one of the most advanced word (editor) of the time, but the speed of floppy drive eliminated the possibility of professional use (OK, the 80 character per line would be also nice)
I wish Commodore would have been smarter and buy JiffyDOS from Mark Fellows and would ship the products with this feature from the factory, maybe with an extra switch for full backwards compatibility. The cost uplift of the change would be almost nothing with 5-10 times speed increase.
Imagine a C64 factory release (package) with Jiffy C64/II, Jiffy 1541/II, GEOS + 256K RAM upgrade, how much it could be a game changer, same speed and capability as an early Apple Classic Macintosh.
Certainly Plus/4 cand 1551 could be upgraded with these features too (I know that Jiffy was developed after Plus/4 release, but was very close)
About the possible speed difference between the C64 and Plus/4 Jiffy due to CPU speed difference:
In case JiffyDOS the data package also changed (AFAIK): so not only the speed of the communication, but the way of communication changed between two devices (using more lines for data transfer).
So, if the receiving end is faster in case of Plus/4 (or able to do handle the bits faster, faster CPU to handle things), then again there could be a difference between the speeds, like the difference between the different fastloaders.
As currently I have no C64 with Jiffy (though I have an 1541 with Jiffy) I cannot 100% compare the speeds, but I think it will worth a try with a 200block file.
We know the typical loading times:
https://www.c64-wiki.com/wiki/JiffyDOS
|
