Author name: vincent

AppleII, SmartdiskII, Uncategorized

SmartDisk II – The Origin

/ / AppleII, SmartdiskII, Uncategorized

I remember the first time I had my first prototype of what will become the SmartDisk II loading the NIB image of BoulderDash II on my Apple II.

The first prototype was made on a very poor quality breadboard with a STM32 Bluepill, with a lot of ICs. The process to load NIB image was not really accurate, but I was so proud of having at least something working. 

This was the beginning of my journey to design and build an accurate Apple II Disk Emulator. I reached out to the Applefritter community for help on this project, and I received more than what I was hopping. This was a few month of long hardworking and debugging session with a lot of up and down along this way.

The purpose of this project was really a personal goal to experiment, learn, understand, and build. My approach from the beginning was … Read the rest

AppleII, SmartdiskII

Smartloader for SmartDisk

/ / AppleII, SmartdiskII

I received a message on AppleFritter to add a new feature on the SmartDisk II. The request was to have the content of the SDCard to be displayed on the Apple II at startup like Slot card are able to do it. I did not reply straight because I was not sure it was possible or not. 

I started reflecting on how I would do it given my knowledge of the DISK II interface card and also the way the SmartDisk II is working. I had an interesting discussion with Antoine Vignau on an approach that would use the SMARTPORT protocol with undocumented function around CMD. With this approach the SmartDisk II would issue a SmartPort CMD with specific parameters that are not used by the SmartPort ROM or the SP6 Rom. I still think this is possible, however the approach would assume that the Apple II has a SMARTPORT … Read the rest

AppleII, SmartdiskII

SmartDisk Rev 8 PCB

/ / AppleII, SmartdiskII

The last stable board revision was rev.4. After doing test with beta revision 5 & 6, a new board revision is now available

While the form factor remains the same, there are a few enhancements in this new release :

  • A power regulator to replace the light one on the blackpill 
  • Diode and power fuse to better protect the SmartDisk
  • Resistor for future Mac floppy drive use.
  • Pull-up resistor to replace stm32 internal ones

If you have a rev.4, there is no need to upgrade and the firmware new version will continue to work on the previous release.

On the revision 8, one need to be careful with the power source and avoid to use 5V and 3V power supply at the same time (or SDIO with 5V) otherwise it will blow up the SmartDisk. On the left side of the board, above the buzzer, there are to power supply … Read the rest

AppleII, SmartdiskII

To a Better Smartloader

/ / AppleII, SmartdiskII

Well, up to the current version (0.36), smartloader was relying on Prodos 2.4 and the MLI kernel to execute Read Write Block. 

The main drawback are launch time (mainly to load prodos (a few second) and the fact that only Apple II with a language card (16k RAM) are able to run ProDos.

A new approach has been considered to address the speed and the compatibility issue. 

This new approach relies on:

  • A custom bootloader on track 0 sector 0,
  • Fast RWTS library
  • The adaptation of the smartloader to use RWTS
  • Everything on a single track 0

The boot loader is the so called stage 1 of the boot process, and it starts at 0x801 (Org is at 0x800 the first byte is 0x01 and used by the boot ROM).

The bootloader will perform 4 steps:

  • Display immediately the Mask of the main screen, 
  • Load the RWTS routines (from sector
… Read the rest
IBM5170

Gotek for IBM 5170

/ / IBM5170

The Gotek floppy disk emulator is a great product and enables to relive most of the retro computer including the famous 5170. 

One of the big challenges to have the gotek to work is the BIOS configuration. the IBM 5170 genuine BIOS of more recent version can support various floppy format such as 

  • 360 K
  • 720 K
  • 1.2 M
  • 1.44 M

If you plan to have your gotek to work with your IBM 5170, you absolutely need to have the BIOS settings inline with your gotek image to be booted, I have spend hours to make it working… In other words, if your bios is set to 720 K drive, you will never boot a 1.44 gotek image. The good news is that the gotek with the fast floppy firmware automatically detect the format of the image to boot. 

Assuming, you have successfully boot your system with your Gotek, now … Read the rest

AppleII, SmartdiskII

Story Behind Bouncing Kamungas

/ / AppleII, SmartdiskII

During my journey to build the SmartDisk II, I made a ton of mistakes, and at the same time I learned so much, but sometimes it takes very long to sort things out. This is the story of the Bouncing Kamungas where I scratched my head. 

The initial software version of the SmartDisk II was using the SPI DMA. SPI is a common hardware interface that enables to send at a given frequency a buffer of bytes. This last word is very important and you will understand why. 

The beauty of the SPI DMA is that it is not blocking or consuming CPU resources everything is done in the back. On top of it you can configure the bytes buffer to be circular and to restart at the end forever, a bit like the floppy disk drive.

SmartDisk was loading image track to the SPI buffer, with a length and … Read the rest

IBM5170

Resurrecting an IBM 5175 Monitor

/ / IBM5170

After a few years to inactively searching for an IBM 5170 (the holy grail), I finally found an auction on a french domestic website. And luckily enough, I was proposed 2 monitors to come with it:

  • IBM 5151 12’’ TTL Logic monochrome monitor
  • IBM 5175 Professional Graphics Display (monitor for PGC card),

Of course, the 5170 was not booting with many defects: 

  • Hard-drive failure,
  • Battery failure,
  • …

Inside the 5170, a MDA (IBM Monochrome display adapter) card was found. The MDA card is working with the 5151 monitor. 

No PGC card…

Both monitors were dusty, with spiderweb, dirty, as you can imagine with being stocked for the last 25 years… And I wanted to check if they were working. 

The 5151 was surprisingly working fine with a bright and clear green on black image. The 5170 was nicely displaying the list of error due to all the defects.

I tried … Read the rest

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