Input/Output

Obviously, Commodore Hacking depends on the comments and article submissions from the Commodore community to flourish. Everyone sees the articles, but let's not forget those comments. They are very helpful, and every attempt is made to address concerns in them. Address any comments, concerns, or suggestions to:

Commodore Hacking
10710 Bruhn Avenue
Bennington, NE 68007
j.brain@ieee.org (Internet)

So, You Think You're Fast Enough, Eh?

From: Ralph Mason

Dear C=Hacking,

Keep up the good work with C=Hacking. I was just reading your article about the Super CPU and thought I would add my 2p worth.

You noted that the SuperCPU appeared to be 21.79 times faster but attributed this to the VIC chip stealing cycles. I think this is only part of the story (the smaller part). I think the most cycles are likely to be lost or gained due to the jiffy interrupt routine. The standard 64 executed this routine 660 times and scanned the keyboard etc. during it's count from 1 to 10000. The SuperCPU only executed this code 31 times. Far more of its cycle was spent actually doing work. I think if you could turn off these interrupts you would find that the SuperCPU is actually running short of the 20 times faster than it appears to be showing.

It's almost stooping to silly IBM style Norton SI numbers or other useless benchmarks. These will never show the true story. From what I've read, I'd guess (user's will see) a real world speed enhancement running real application of around 400%, more or less depending on the app.

Cheers,
-Ralph Mason

Jim Brain replies,

Ralph, after reading your explanation, I think you are correct in stating that the bulk of the time saved on a 20 MHz unit is indeed due to the fewer interrupts it must service in a given time frame. However, since we can rarely turn off the 60 cycle interrupt, the effective speed is what people will notice. Also, while I think you are correct on this discussion waxing philosophic, I believe most users should see more than 400% increase in applications. Of course, YMMV (Your Mileage May Vary).

A Round of Ice Water for the Editors

From: drankin@crashb.megalith.miami.fl.us (Dave Rankin)

Thank you for all your efforts and putting out this Mag. I and many others do enjoy seeing all this activity for the 8 bit Commodore.

Dave

Thanks for the letter. We always enjoy knowing that the hours we spend producing this magazine are appreciated by those in the community that read it.

There's Nothing Like the Real Thing, Baby(tm)

From: cjbr@gonix.gonix.com (Jim Lawless)

Dear C=Hacking,

Just wanted to express my enthusiasm for your electronic publication and hope to make regular contributions in the coming months.

I was a C64 hacker from '84 until about '87 when I progressed throughout the Amiga and into the PeeCee world.

I found out about the C64 emulators for MS-DOS/Windows...etc. and downloaded one this morning. It was a great feeling seeing the '64 startup screen again!

My wife expressed some curiosity seeing a pile of old Transactor magazines next to the recliner today. I told her how excited I was about the emulator.

This evening, she returned from a church auction with a C128, a 1541, a 1650 modem, a westridge mode, and a bundle of software all for $30.00.

I guess it's time to get back to my roots and have some fun!

Jim Lawless,
cjbr@gonix.com

We appreciate the thanks. In addition, we always encourage Commodore enthusiasts to submit articles to the magazine. However, we are most grateful that you have come home again. While emulators have their downside, we have noticed that many who download one end up buying a real machine and rediscover the simple elegance of the Commodore computer. We applaud you for your choice.

Copy Rights!

From: EricJ1@aol.com

I'll make this short and sweet. But, I have to tell you, I love C= Hacking. I'd like to post this as a public bulletin on my BBS if it is not a problem.

Thanks

Eric

We encourage redistribution of Commodore Hacking for non-profit means. Simply read the guidelines in the issue's legal statement (Reference: legal). As long as the conditions in that guide are met, we would love to see C=H spread throughout the Commodore community.