'Disk drive documentation'
Author:SaxxonPike (registered user: 16 posts )
Date: Sat, Nov 10th, 2012 @ 01:20 ( . )

Hey guys,

I have been tasked with adding Commodore 64 support to an emulator aimed at the Tool Assisted Speedrun community called Bizhawk. I have been able to implement most functions of the C64 with great success, due mostly to great documentation of the inner workings of the onboard MOS chips. For now, cartridge based games are working. I need to implement disk images soon.

However, there doesn't appear to be a whole lot of documentation on the inner workings of the disk drive that I can tell. There doesn't seem to be much information on the VIA chip used in the drive either. We plan to use a specific setup, and one specific drive, the original 1541. Do you know of any great sources of information for the drive? I know all of you here are a fantastic resource, but I don't want to task any of you with posting a complete writeup of the inner workings of the drive.


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'Disk drive documentation'
Author:Nate (guest: search)
Date: Sun, Nov 11th, 2012 @ 02:32 ( . )

Read the VICE source code. The most recent versions patched by the Kryoflux team have excellent drive emulation.

[link]


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'Disk drive documentation'
Author:bluebirdpod (registered user: 28 posts )
Date: Fri, Nov 16th, 2012 @ 12:05 ( . )

They said they patched Legend of Blacksilver, and Defender of the Crown to work with the Kryoflux patched Winvice, but if you manually load Blacksilver it works fine, autostarting does not work, but it does on the Kryoflux'd winvice perfectly every time. I wonder if they are going to keep the kryoflux emulation seperate or integrate it into the Viceteam releases. (does anyone know if side two's protection on DOTC is present? and working? Pete said it did not work on the images from his collection, they had to be patched with Ramboards side two parameter? Is this still true ?)


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'Disk drive documentation'
Author:Lord Crass (guest: search)
Date: Sat, Nov 17th, 2012 @ 00:09 ( . )

It's all fixed. LoB used a different timing routine for stepping the drive head (simple countdown loop rather than VIA timer) and they fixed some timing issues that prevented it from working 100%.

Yes, the DoTC side 2 protection check now works without requiring a parameter. They added some code that uses the track length to determine density and appropriately altering the delay between bits appearing under the virtual drive head.

Kryoflux team also fixed the secondary VIA timers that were used in a few V-Max titles as part of a drive-side decryption loop, so those work now (Thunder Mountain's Galaxian, Felony, and some other one)

Also, Rapidlok works properly without having to patch out any checks.


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