Blogs

A1 in Walnut case

Submitted by Zero dB on December 6, 2023 - 1:03am

My latest A1 build. Case is walnut.  

Thank you for all your help Uncle Bernie.  

Getting your Apple II VGA Card up and running: Ralle Palaveev version

Submitted by skate323k137 on November 20, 2023 - 6:25pm

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The Ralle Palaveev VGA card is an extension of the Apple II Vga project by Mark Aikens. A few versions of this project exist, but this post is focusing on the Ralle Palaveev version, which has a lot of capabilities (and the added complexity that goes along with them).

Ultima V MIDI with hidden arrangements

Submitted by S.Elliott on November 20, 2023 - 11:58am

For preservation:

A collection of MIDI files extracted from Ultima V in 1995, copied through a MIDI cable to a Roland SCC-1, saved for decades on a 3½" floppy disk, reproduced here on a GS-compatible Roland MT-120.

A full performance is recorded here, and on YouTube.

Artifacts hidden inside the MIDI data reveal hidden arrangements and sound effects that were not reproduced during game play -- including percussion and sound fx that were probably reproducible only on the original composer's equipment.

DAN ][ THE FUTURE: Boosting your favourite 80s machine to "8.59 jigobytes"

Submitted by MacFly on November 6, 2023 - 4:12pm

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Imagine in 1980-something you started your Apple ][, /// or //e - and you had 8 gigabytes of storage... Mind blowing?

Well, if you have a DAN][ Controller card, you can now easily boost your 1980s machine to 8GB. In decimal numbers, the maximum usable storage now supported by the DAN][ Contoller is actually 8.59GB. That would certainly have spooked Doc Emmett Brown in 1985 - though he'd have pronounced it "8.59 jigobytes", of course... But no need to accelerate to "88 miles per hour". All it takes is a simple firmware update.

Tags: 
BTTF DANII APPLE2 APPLE3

The Brain Board II: Bringing Integer BASIC and Apple 1 emulation to your Apple IIe/II+ with a single card

Submitted by skate323k137 on November 1, 2023 - 12:55pm

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I have released an updated ROM for the Brain Board II, with the focus on making it a true dual purpose card. This allows a user (especially with known good Applesoft BASIC roms / IIe system ROMs in their system) to bring Wozaniam (Apple 1) mode and Integer BASIC to a system with one card, and also always leave the systems own ROM space usable. This is nice if you have a system already nearly full of expansion cards and your ROM version is happy as-is, since previously to have both integer and applesoft BASIC with this card, you had to disable your system ROMs entirely.

Tags: 
Apple II

UNCLE BERNIE'S CODEBREAKER GAME

Submitted by rob101 on October 29, 2023 - 1:26pm

A preview of the the readme.md file that will be hosted on GitHub, along with my Python implementation of the game known as UNCLE BERNIE'S CODEBREAKER GAME

Tags: 
games

Apple /// Reset Logic & Apple II Emulation Flaws

Submitted by MacFly on October 8, 2023 - 4:18pm

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I recently ported software from the Apple II to Apple III and encountered an interesting topic. It's a corner case, but in my opinion a typical example. It shows how the Apple III design was sometimes (maybe unnecessarily) complicated. And how features introduced Apple II compatibility issues.

Tags: 
6502 APPLE III NMI RESET

The (not so) subtle differences between 6502 assemblers...

Submitted by MacFly on July 25, 2023 - 6:24pm

Oh man... I was not aware of the pitfalls when switching between different 6502 assemblers. Until now, when I tried to reuse an old assembly listing (from Apple II assembler/editor) with the ca65 cross-assembler...

Carefully compare the definition of the > and < operators to obtain the low or high byte of an 16bit address - in these two excerpts from the respective manuals...

Using the "Phi1 Echo" to distinguish disk controllers

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

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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

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