Hacks

Using the "Phi1 Echo" to distinguish disk controllers

Submitted by S.Elliott on July 1, 2023 - 5:49pm

capture328.png

Apple hid a quirky feature inside its disk drives, a full-loop signal path via addressable latch Q1, via stepper phase-1, via the motor control board, via the write-protect switch, via the analog board in the disk drive, via the shift-right input into the data register, and back onto the bus.  This signal path can be used to distinguish between the various Apple II disk controllers.
  • Apple Disk II controller prints 2 inverse bytes: 7F 00
  • Micro Sci A2 controller prints 2 inverse bytes: 80 00
  • (untested guess) IWM in Apple //c: A0 20
  • (untested guess) IWM in Apple //c+: AF 2F [EDIT: this guess was wrong]
Tags: 
hardware

Quick ref: Pass arguments to machine code from the Monitor

Submitted by S.Elliott on April 28, 2023 - 6:18pm
When calling a machine code subroutine from the Monitor, one or two additional arguments can be passed by taking advantage of the way the Monitor uses delimiters to parse arguments from its command-line and stores them in the zero-page pointers A1, A2, A3, A4...in an arbitrarily-strange order:
  • The default argument is always the subroutine address, stored in A1.
  • Appending a '.' delimiter allows another argument to be stored in A2.
  • Inserting a '<' delimiter allows an argument to be stored in A4.
Tags: 
monitor
asm

Transmitting a simple datagram via Video Vapor

Submitted by S.Elliott on April 4, 2023 - 5:36pm
Synopsis:
  • Define a short datagram to be transmitted via vapor from visible screen memory.
  • Encode single-cycle accurate video phase via vapor datagram.
  • Construct a routine to receive the vapor datagram and synchronize itself to the video scanner.
  • Write a simple BASIC program to demonstrate all that!
Tags: 
vaporlock
asm

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!

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

Power Mac G4 (MDD) ATX Power Supply conversion

Submitted by eeun on January 6, 2009 - 3:53pm

IMAGE(/files/images//pluginstalled2-23483_0.jpg)
One dead G4 (Mirrored Drive Doors) power supply. There's nothing visibly wrong that might have been an easy fix, and the PSU is pretty densely packed with a lot of silicon caulk applied to keep components from shifting. Better to start from scratch with an ATX power supply...

Content Type: 
Hacks
Electricity & Optics Hacks
Computer Type: 
Power Macintosh
Manufacturer: 
Apple

Glowing Wallstreet

Submitted by westieg3 on July 3, 2006 - 7:29pm

IMAGE(/files/styles/large/public/daylight.jpg)
Modify your PowerBook G3 Wallstreet's case so that light from the LCD will pass through the Apple logo.

Content Type: 
Hacks
Laptop Mods
Computer Type: 
Power Macintosh
Manufacturer: 
Apple

3.5" hard drive on laptop/Mac Mini internal IDE

Submitted by Whosawhatsis on February 23, 2006 - 4:41pm

IMAGE(/files/styles/large/public/images//assembled-10852_0.jpg)
Want a cheap way to add storage and speed to a stationary laptop that might not have Firewire or USB 2.0? Disappointed that your Mac mini uses a puny little laptop hard drive? If you've got a desktop hard drive that you'd like to connect to either of these, it's possible with a little work.

Content Type: 
Hacks
Laptop Mods
Hardware Guides
Manufacturer: 
Apple

SportPod

Submitted by Dr. Webster on December 16, 2005 - 8:06pm

IMAGE(/files/styles/large/public/sportpod3.jpg)
The SportPod is a custom, weatherproof iPod case made from an old sports radio. Learn how to build your own.

Content Type: 
Hacks
Peripheral Hacks
Computer Type: 
Apple, Other
Other Technology

Darth Maul PowerBook

Submitted by drbob on June 11, 2004 - 7:56pm

IMAGE(/files/styles/large/public/images//pbangle-3212_0.jpg)
Spooky, no?

Content Type: 
Hacks
Laptop Mods
Computer Type: 
Power Macintosh
Manufacturer: 
Apple

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