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Posted By

C=Owl27
on 2020-12-23
03:35:41
 1541 JiffyDOS Kernal Adaptor Question

I'm looking to install JiffyDOS into a 1541 drive.
(Fortunately it is socketed)
That is I want to make an adaptor for my EPROM.

Reading over a tutorial @...
symlink.dk/Nostalgia/Commodore 64/C64 ROMs
He is using a 27256 chip to burn 3 kernals to.
(He admits to being able to have 4 kernals, but is only using 3 with his switch)
His adaptor converts the 28 pin EPROM to the 24 pin 2364.
The diagram shows his chip has VPP at pin one of his 27256.
And the switch is between this line, and the CE pin of the 27256.
(Vpp/Vcc/resisters/switch)
His OE is connected to the CS of the 2364 chip.

Right now all I have are Winbond W27C512 chips.
The datasheet says that it's OE and VPP are the same.
Being that the case, could I run that side of the switch
to the Winbond's OE/VPP and work correctly?
(even though the OE is also connected the 2364's CS?)
(I understand this is probably already apparent for those in the know.)

Here is an image of what I have in mind:
https://i.ibb.co/NYGYJNz/Adaptor-Winbond-Jiffy-Dos-Question.png

Do you think this adjustment for my Winbond W27C512 chip is appropriate?
Or could I use the exact same adaptor for my chip that the tutorial uses?

On another note, I installed JiffyDOS into the Plus 4,
however without a switch. (No not a switchless version.)
I did this as experiment.
Would the start up default to JiffyDOS, or to the native kernal?
It does default to JiffyDOS, but that is all I burned to the chip anyways.
(Not sure if JiffyDOS bin includes native kernal or not).
And wow what a difference!
In conjunction with my SD drive, the load times are astounding!
A 47kb program now loads in 4 seconds!
What a game changer.
Does anybody know if JiffyDOS also provides the native kernal?
Or does this have to also be burned to the chip?

I plan to follow Ray Carlsen's example of a switchless reset approach.
(For the Plus 4.)

Posted By

Retroshire
on 2020-12-23
04:32:38
 Re: 1541 JiffyDOS Kernal Adaptor Question

Standard there is just the Jiffy binary, you have to merge it with the stock kernal.

Posted By

siz
on 2020-12-23
05:13:53
 Re: 1541 JiffyDOS Kernal Adaptor Question

Most probably you want to head to https://store.go4retro.com and purchase JiffyDOS for your plus/4 and the drive too. JiffyDOS is still copyrighted, that's the official source to get it. And Jim Brain will ship it in a switchable fashion (I own JiffyDOS for the plus/4 and found some software which won't work with it).



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