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Tech by Androda, LLC

This site will chronicle my adventures with vintage computers and hardware, electronics in general, and any software which appears along the way. I want to create solutions for vintage computers which don’t require large amounts of configuration or tinkering to make them work.

See the Shop section for:
* Various styles of BlueSCSI™ V2, including Desktop, PowerBook, DB25, and Centronics 50 pin
* The HIDHopper™ Adapter Series, for converting modern USB keyboards and mice to vintage standards
* Newton and eMate Products
* New Old Stock Networking Hardware and Adapters
* A wide variety of products for the Macintosh Portable
* Recreated parts for vintage systems

Ping me with questions at the contact email listed on the About Page.

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The Return of the Kits

BlueSCSI Desktop kits are finally back, both in Standard and Wi-Fi enabled.

This is due to a new quick-test platform which allows verification of the SD slot’s soldering so theoretically there will be no more issues with the SD card in kits. SD card communication issues were the #1 cause of kit issues before, and this ought to wipe that out completely.

What does the test platform look like? It’s a 3D printed handle around a few custom PCBs, as seen below:

Pico Pogo Pin Performance Poker Platform, or P⁶

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10/100 Comm Slot II Ethernet Cards

Update: Production order has been placed for these cards. Approximately one month until production completion, then they need to be tested prior to listing for sale.

This is an upcoming product announcement.

Comm Slot II Ethernet cards have been expensive and hard to find for quite some time now. And as it turns out, Comm Slot II is basically just PCI with fewer signals. Thus, a project was born.

A thread has been started on Tinker Different about these cards: https://tinkerdifferent.com/threads/comm-slot-ii-10-100-ethernet-cards.3658/

Farallon produced a 10/100 Comm Slot II card “back in the day”, but it had some compatibility issues and other problems based on old posts at zone6400.com

After spending several weeks looking around for information about Ethernet chipsets and Mac OS compatibility, I found one which is very widely compatible (tested on 7.6 through 9.1) and is a convenient single-chip solution unlike the Farallon which needed the 100 megabit driver separate from the PCI-side controller.

Speeds have been low in testing, unfortunately – only 150k per second max download. But this is the speed I see from PCI cards of the era on my 7300 that’s upgraded with a G3 card. So I’m confused, I expected far better than that from a 10/100 chipset. Not sure if there’s something I am doing wrong in configuration or what.

For your viewing pleasure, the card is pictured below:

Comm Slot II Ethernet Card
Comm Slot II Ethernet Card
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A decided lack of Desktop BlueSCSI Kits

I’m sure you have all noticed that Desktop 50 Pin BlueSCSI kits have been out of stock here for way too long. This is due to some production struggles – the SD card slot in particular.

For some reason this component has been soldered improperly on a substantial number of PCBs, such that the manufacturer thinks everything is OK (automated optical inspection says “here be solder”) but the connection is actually a “cold solder joint” that needs solder rework to function properly.

I’ve mentioned this to the manufacturer in the hopes that they can pay more attention to it, but it won’t be possible to tell whether they changed anything without further orders.

To help with this situation I’m working on a tool that should allow for testing the kit PCB before sending to ensure the SD slot is actually functional. This should prevent the majority of bad slots from being sent out in kits.

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Unintentional 2024 Marchintosh Project

Unintentional is the name of the game here, this project entirely by coincidence happens to be in March so why not talk about it?

What is it? A Macintosh Portable to VGA Adapter, using the RP2040 and Pico Scanvideo library.

I will be working on a PCB for this design soon (presently it’s on a breadboard) and hope to have it available for sale by April. That is, if my spare time permits.

Picture time:

The Converter On A Breadboard With Wires Everywhere
Fish Screensaver on LCD Screen
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Feb 9 Stock Update

Feb 27 Update:

A batch of Desktop 50 Pin boards is on the way now, with parts procurement in progress for more. Estimated availability is March 1st or 2nd.

Feb 15 update:

BlueSCSI Desktop is basically out of stock. I’m working on ordering more of these, the Portable RAM Card, Portable Battery Eliminator, and several other products to keep up with demand.

Original Post:

Hello everyone, thanks to our friends Adrian and Veronica there has been a huge surge in BlueSCSI orders. I’m trying to keep up, and will run out of Desktop style PCBs soon (only 20-ish left).

Thanks for your patience as I restock in my available time.

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2023-11-14 Update

Parts and PCBs for the Mac Portable Battery Eliminator have been ordered (the tiny available stock was the final verification design). And a PCB order is in for what I hope is the last HIDHopper ADB revision before production quantities can be run.

The Switchable Mac Portable RAM card had some production issues last time around that I’m still figuring out. Hopefully it was just bad soldering.

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Upcoming Products

Other than the normal-priced BlueSCSI desktop design which is incoming, what else is there to look forward to as we approach the end of the year?

Far too many things for my spare time to be very happy.

First, a product for the Mac Portable which should resolve once and for all the problems that are caused by its Lead Acid battery and the maintenance that requires: The Mac Portable Battery Eliminator.

It hooks up to the Modem slot, requires a small (included) jumper cable to connect to the motherboard instead of the original battery harness, and uses Supercapacitors to take the place of the battery. Plug your power adapter into this card through the Modem port’s cutout, wait 2 minutes for the capacitors to charge, and that’s it. Never bother to charge a lead acid battery again. Also includes solder points for a 9v battery clip if you demand PRAM retention, but supercaps have high discharge so don’t expect great battery life.

Second, an update to the Mac Portable 7 Meg RAM card which includes the switching option by default (I don’t have to solder things to the CPLD any more, hooray). This will entirely replace the base model 7 megabyte card after those are sold out, and will sell in parallel until then.

Third, an entirely new product line. Are you tired of having to find original keyboards and mice for vintage Apple, Sun, and other systems? Say hello to the HIDHopper series. This line of affordable interface adapters is planned to start with USB to ADB, and will expand from there to a variety of vintage systems with impossible to find (or overly expensive) input devices.

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BlueSCSI Desktop Hardware Update

The new hardware version has passed my local testing (PM 7300, Beige G3, Mac Portable, initiator mode verification) and the BlueSCSI Distributor Group have started placing orders for it.

As mentioned before, some things are removed. The dedicated USB-C port is gone, as well as the second SD slot (now only full-size like before). And the PCB is back to 2 layers instead of 4, which is probably the largest driver of that cost increase.

Prices for the Desktop version will decrease back to the normal level as soon as the new boards arrive, which are expected the week of the 13th.

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Short-Lived Hardware Design

The BlueSCSI Desktop hardware version 2023.09a is going to be very short-lived.

Turns out production costs on this one are rather dramatically more than older designs, and the BlueSCSI Seller Group really doesn’t want to have to raise prices (a good goal). You’ll note that I increased prices for the Desktop model because it really does cost way more to make, and that will decrease back to normal after the new hardware version is available.

I have designed a substantially cheaper to manufacture version which will be hardware 2023.10a. It gives up a few things:
* Dual SD slots will be reduced to one
* No more USB-C port onboard

The Initiator Mode feature will remain intact, don’t worry about that. And the 2023.09a Desktop version will continue to be supported with new firmware releases and such (one binary for all!).

Once the new October hardware version is tested, it’ll be released and start to become available as sellers pick up that design.

Sorry for the confusion, I didn’t expect production costs on the November design to be so crazy high.

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BlueSCSI Initiator Mode (And stock update)

You have probably all noticed by now that I’m out of stock of the Desktop BlueSCSI variant. This is due to a combination of working on Initiator Mode support for BlueSCSI hardware, and forgetting to order more of the previous PCB design.

What’s Initiator Mode and why is it kind of a big deal? I’m glad you asked.

Initiator Mode allows BlueSCSI to act as a SCSI Host device. You know how currently BlueSCSI needs a working vintage computer before data can be copied over? Your device (be it a Mac, PC, Amiga, whatever) needs to be bootable so data can be copied onto BlueSCSI. With Initiator Mode you can connect BlueSCSI directly to a target hard drive that needs to be backed up, configure BlueSCSI properly, and it will pull the contents of that drive directly into a disk image on the SD card. A bootable “host system” will no longer be required to take drive backup images.

Why didn’t BlueSCSI support this already? At first I didn’t think it was possible on the Pico stick given the number of additional GPIO signals it seemed to require.

The RP2040 microcontroller exposes several more GPIO signals than the Pico does, because the Pi Foundation used them for things like monitoring and power management. For example GPIO 24 monitors voltage input and GPIO 23 can be used to switch the RT6150 buck regulator chip into a lower power mode. Another pin (GPIO 25) controls the LED. And GPIO 29 is used to block leakage through the ADC3 pin when the 3.3v supply is disabled. So that’s a few GPIO pins gone already on the Pico stick. The Pi Foundation seems to have been desperate to stick to 2×20 pin headers, and they could have switched things around to expose USB over the headers but I digress.

So then how is it possible if we’re missing so many pins? Basically every pin which is connected to the SCSI bus does double-duty. They are all either an input and output signal, or inputs for two different signals.

How can a pin be both an input and an output? With resistors and the LVT/LVTH125 bus buffer chip, that’s how. A typical dual-function pin is structured like this:

This is an excerpt from the schematic showing the ACK signal. This signal when in “Target Mode” (acting like a normal hard drive) needs to be an input, iACK. And in Initiator Mode it needs to be an output. This configuration allows the input bus buffer to speak to the Pico pin (going off to the right) while also allowing the Pico to override that signal and drive the output as necessary.

As shown here, when oBSY is asserted (grounded, 0v), the iACK signal there on the left is buffered to the ack input signal pin through R67 shown above. And when oBSY is not asserted (3.3v) the state of the ACK line is determined by that output pin on the Pico. But wait, you say – you can’t just override ACK all the time! You’re right. This is why there are not one but two jumpers which need to be set to switch BlueSCSI into initiator mode.

One jumper switches which input line is being listened to by a certain GPIO pin (can’t just OR them together or they would collide and cause odd behavior, they must be separate). And the other jumper enables the Output ACK (oACK) signal.

The first production versions of Desktop BlueSCSI which support Initiator mode are in manufacturing now.

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BlueSCSI V2 WiFi Instructions

If you choose the WiFi option, instructions on how to set up the DaynaPort emulation can be found here:

https://bluescsi.com/docs/WiFi-DaynaPORT

Please note that you will need to add two new files to your SD card.
First, “bluescsi.ini” which is a plain text file. Its contents will look something like the below. Substitute your WiFi network name and password into the file.

[SCSI]
WifiSSID = "NetName"
WifiPassword = "NetPassword"

The other file you need to add defines the SCSI ID for your emulated DaynaPort device. This can be an empty plaintext file, it does not need any contents. Name it “NEx.txt” where the ‘x’ is your preferred SCSI ID. For example, “NE4.txt”. The above instructions say to use “.hda”, but the file extension is unnecessary currently because BlueSCSI stops reading the filename after NE4 anyway.

If you already have other SCSI hard drives defined on your SD card, don’t use the same ID as one of them or the network device will be ignored.

You must configure both the bluescsi.ini file and the network device file or DaynaPort emulation will not work. Your system might not even boot, because wifi configuration without a network device will hang.

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DefCon 31 Badge Addon Design Files

For those of you that did not know, I attended DefCon this year (and have been for a few years now). It’s quite an experience being surrounded by so many people with a similar mindset on security in general.

This year I decided to make a badge addon, and all the files related to that can be found here. I handed these out at the conference, and didn’t have very many.

It’s a “Heat Index” indicator, which basically calculates the perceived temperature based on the combination of actual temperature and current humidity levels. Then it flashes an LED once per second to indicate those calculated values. Really overall it’s nothing special, but was a fun and challenging design exercise.

It also acts as an STM32F030 breakout board, so you can reprogram it to do something more useful later on. 🙂

This was a good practice activity for another hardware market I want to get into, which will probably take a lot of time and prototyping before anything particular is released.

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Macintosh Portable RAM Cards

You may have seen my post on TinkerDifferent, and the rumors are true. I am working on a 7 megabyte Mac Portable RAM card using all-new components (nothing New Old Stock).

It has been tested on my M5120 Portable, and I sent one to Techknight for review on his M5126 Backlit Portable. Assuming the tests pass, I’ll do a small run of probably 5 or 10 cards as pre-production verification, and then the cards will go into normal production.

The best part? These cards will not cost $190, $150, or even $100. They’ll be somewhere in the $55 to $65 range.

This will mean that you can get almost everything your Portable could need straight from my site:
* Replacement Hybrid Modules (which will be back in stock in a few weeks)
* New Screen Cable (for the Backlit model)
* BlueSCSI Hard Drive (Plus Portable-specific Adapter)
* RAM Card (Link to be added once they’re available)

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Hybrid Module Recreation and eMate 300 Upgrades Stock Status

There has been a sudden surge in interest toward the Mac Portable Hybrid Module Recreation and my various eMate 300 RAM and Flash upgrades. They are presently out of stock, and I hope to get things available again in the upcoming week using part and PCB stock that’s presently available.

An order for larger quantities of the Hybrid Module has been placed with a PCB manufacturing / assembly group, but that’ll take about a month to complete. It’ll help with pricing as well, as these modules are hand-assembled currently which takes a lot of time and effort.

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Coming Soon: Mac Portable Adapter

I’ve been contacted by a few people lamenting the Mac Portable BlueSCSI I was selling previously – it’s no longer listed in the shop.

Good news! An adapter is on the way from the PCB manufacturer now. This will allow a standard 50 pin Desktop BlueSCSI to be connected to your Mac Portable, for great retro computing (and battery savings).

UPDATE: The adapter has been released and is in the shop now.