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Various High Quality Disk Sleeves - not scanned reproductions

Submitted by Khaibitgfx on February 8, 2023 - 4:59pm

It is recommended that Adobe Acrobat be used as these files have been created with modern Adobe apps and use many up to date font features.

 

https://www.applefritter.com/files/2023/02/08/A%2B%20525%20floppy%20sleeve.pdf

 

https://www.applefritter.com/files/2023/02/08/AE%20525%20inch%20floppy%20sleeve.pdf

 

https://www.applefritter.com/files/2023/02/08/MECA%20525%20floppy%20sleeve.pdf

 

https://www.applefritter.com/files/2023/02/08/MECC%20525%20inch%20floppy%20sleeve.pdf

 

KR9600 Tester

Submitted by S.Elliott on January 10, 2023 - 9:31pm

The KR9600-PRO keyboard encoder has a bug of sorts.

So does the AY-5-3600-PRO keyboard encoder, according to page 7-12 of Understanding the Apple IIe by James Sather.

But despite being a drop-in replacement for the KR9600-PRO and AY-5-3600-PRO, the JCM-1 does not exhibit the aforementioned bug.  Well done!

Two-disk replica of Prince of Persia

Submitted by S.Elliott on January 3, 2023 - 5:36pm

A recent discussion of a buggy crack for Lords of Conquest raised the issue of preserving the original bits from protected software.

So I'm exploring a different approach -- instead of patching games to bypass copy-protection code (ie: 'cracking') why not devise methods of satisfying the copy-protection checks without patching the code?

K-7

Submitted by doug-doug the mighty on January 1, 2023 - 9:22pm

K-7 is my main dektop for working from home at my jobsite location. The purpose of this blog is to document my configuration for reference and troubleshooting purposes.

Side-by-side graphics/text windows

Submitted by S.Elliott on December 6, 2022 - 3:10pm

This blogpost is a partial-transcript of a discussion from Apple2Infinitum on Slack, which was spawned from an even older Facebook thread.  Since it isn't easy to view the old discussions on Slack and Facebook, I've copy-pasted the messages, pictures, and code blocks below...

 

Scott Elliott Sep 3rd 11:29:17 AM

Tags: 
vaporlock

Nibble Histogram: the seeds of a disk-o-scope

Submitted by S.Elliott on November 28, 2022 - 9:40pm

What is the distribution of raw nibble values of the bitstream a Disk ][ controller would read from an ordinary DOS diskette?

What values would arise from a copy-protected game disk?  Or from a .DSK emulation of a diskette?

This little routine captures incoming nibbles and computes a moving-window histogram of their distribution.  The data usually stablizes after about 8 calls because it applies a base-2 logarithmic decay to the values after each iteration.

Tags: 
diskOscope hardware

Voyager

Submitted by doug-doug the mighty on October 11, 2022 - 6:51pm

Voyager is the name of my principle laptop. The purpose of this blog is to document my configuration for reference and troubleshooting purposes.

Enterprise_A

Submitted by doug-doug the mighty on October 7, 2022 - 7:48pm

Enterprise A is the name of one of my secondary laptops. The purpose of this blog is to document my configuration for reference and troubleshooting purposes.

EPROM data rot in my EPROM programmer's EPROM

Submitted by S.Elliott on July 3, 2022 - 10:24pm

I recently discovered that some of my custom EPROMS from the 80's and 90's are exhibiting problems due to EPROM bit rot, which falls under the general category of data degredation...or 'data rot'.  Bit rot causes any programmed 0 bits to revert back to 1 bits, their un-programmed state.  The chip isn't actually harmed, it just loses its prorgamming. 

Tags: 
data rot
EPROM
AP64

A very effective Applesoft memory test

Submitted by S.Elliott on June 26, 2022 - 5:38pm

Here's a simple-but-effective Applesoft program that rigorously tests main memory.

In its first pass, the program uses Applesoft's pseudorandom number generator to fill addresses 4096 through 49151 ($1000 to $BFFF).

In its second pass, it resets the pseudorandom number generator and computes the same sequence again...but this time it compares the values that were previously stored in memory and detects any that don't match.

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