Commodore 128 Alive!

Commodore 128 => Herdware => Topic started by: xlar54 on September 30, 2024, 04:48 PM

Title: Interesting Z80 mod
Post by: xlar54 on September 30, 2024, 04:48 PM
Double the Z80 clock speed in your Commodore 128 (youtube.com) (https://www.youtube.com/watch?v=p9dZlJVGQig&ab_channel=RetroTechInsanity)
Title: Re: Interesting Z80 mod
Post by: Blacklord on October 01, 2024, 09:02 AM
Coupled with the CPM Fast binaries (in 80 col mode) this would make the 128D a rather useful CP/M machine.
Title: Re: Interesting Z80 mod
Post by: BigDumbDinosaur on October 04, 2024, 07:00 AM
Quote from: Blacklord on October 01, 2024, 09:02 AMCoupled with the CPM Fast binaries (in 80 col mode) this would make the 128D a rather useful CP/M machine.
Way back when I first hooked up my C-128Ds (two of them) to the Lt. Kernal, I created a CP/M logical unit on the Lt. Kernal and ran CP/M from it.  It ran light-years faster than from the 1571, which was not unexpected, given that CP/M tends to be disk-intensive and is saddled with an inefficient filesystem.

CP/M on the 128, as a whole, is poorly-implemented, due to the constant switching between the Z80 and the 8502 during I/O operations.  While its performance was adequate in the Lt. Kernal environment, I never considered CP/M operation on the 128 as a viable environment for software development.  The 128D running natively on the Lt. Kernal was faster and had access to Lt. Kernal DOS features that weren't available in CP/M mode.

On a different subject, I tried to restore some images to one of my posts from long ago, without success.  I was able to upload the images, but they aren't visible.
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