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New Project Series: MACAA

F4 BlueSCSI is now finished and up for sale in the shop. It’s faster than the original BlueSCSI, but more expensive because the “Black Pill” modules cost more.

My next target are the power supplies in your old Macs. They’re getting old, and in some cases replacing the capacitors isn’t enough to fix them. Thus, new supplies are needed.

Enter the MACAA (MACintosh Atx Alternative) – a project to recreate power supplies for these old Macs using all-new components. Note that this is the ATX Alternative and won’t focus on using ATX or PicoPSU supplies unless that makes the job a lot simpler.

First target is the Macintosh LC Series. LC, LC II, LC III, Quadra 605, LC / Performa 475, and all the other LC clones which use the same supply. PCB design for the MACAA prototype is done, and an order will be placed soon.

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New Hardware Support For BlueSCSI™

For the last few weeks I’ve been working on porting the BlueSCSI software to the “black pill” F401/F411. Getting close to something usable now (it boots), and it comes with a speed increase.

“Blue pills” will run at about 900k read, 650k write. The black pills run at about 1100k read and 800k write. So, not a huge speed increase but it’s something.

Will be getting some prototype PCBs made for testing in desktops and powerbooks to see if compatibility is different. The higher clock speed and faster response times of the black pills probably mean that timings on the bus have changed, and I don’t really know how well the software complies with standards anyway.

My next targets are probably the STM32L412 and STM32G431, as these are pretty low cost and could be integrated into the board (no more ‘pill module’ required).

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Newton Serial Board Works!

Basically the only thing left to do is find the correct mounting screw, one which is as thin as possible (and might require a countersink on the board itself to fit properly). Mounting screw in the upper right corner is hard to line up because if the internal expansion slot connector isn’t perfectly aligned then the error is multiplied across the distance and that hole just won’t line up.

Additions since the last prototype run:

  • Switch for either forcing the chip on or listening to the chip enable pin
  • Additional footprint type for the chip in case you can’t find the CG variant of LTC1323 chip
How it looks installed
You really have to trim down the port to fit properly
Back of Newton doesn’t appear to flex very much
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Newton Serial Boards on the way

My next (hopefully final) iteration of the newton 2×00 serial board is on the way from the PCB manufacturer now. Moved some things around so two different chip types can be used (in case you find the one or the other) and added a switch to override Newton control of the serial transceiver.

This way you can turn it on, install the control software, and then flip the switch the other way to let the Newton control it. Should hopefully not affect battery life too much.

Need to order the switches and some more serial ports. Unfortunately I haven’t found a source for surface-mount circular serial ports so that means I get to have the fun of snipping the leads down to less than 0.6mm (PCB thickness) to avoid bending the case of the Newton.

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Projects In Progress

Currently I have too many several projects in progress.

  • Newton 2×00 Internal Serial Board
    • Prototype PCBs have been made
    • PCB is being updated to be easier for people which don’t have a way to install the necessary software first
    • Looking for a source for surface-mount MINI-DIN 8 connectors (the circular serial port) because the vertical space available is extremely tight. If you know a source, please email me (see the About page)
  • BlueSCSI™
    • BlueSCSI is trademarked by Eric Helgeson
    • https://github.com/erichelgeson/BlueSCSI
    • It’s basically a SCSI drive emulator that uses SD cards for storage. No more need for those old SCSI drives, just use BlueSCSI™
    • I am working on some carrier boards for the BlueSCSI™ ‘blue pill’ module
      • PowerBook
        • Working on getting a Shop listing up for this
      • Desktop
        • Have PCBs, need assembly and testing
      • Macintosh Portable
        • Have prototype PCBs, needs assembly and testing
  • Macintosh Portable Hybrid Module Replacement
    • Have a Mac Portable with a bad hybrid module? Don’t we all.
    • This module will use modern buck regulators in place of the original linear regulator design
    • A microcontroller will handle battery voltage signaling to the power manager chip
      • Any other necessary enable/disable functions will be handled by this chip