MacSD - Multi-device SCSI adapter with audio

[YMK]

MacSD is a SCSI adapter for Macs, DOS, Windows and other platforms.

It's a bus-powered device in a 3.5" drive form factor.

Feature summary:

• Reads up to 3.2MB/s, writes up to 2.5MB/s (PowerMac 6100, 57MHz clock speed)
• Hard drive images
• CD images - Data CD, audio CD, mixed mode, iso, bin + cue/toc
• Composite images - Allows mounting of multiple floppy / volume / MiniVMac images under one SCSI ID
• CD audio output - Stereo 44100Hz at 12.45-13.28 bit resolution
• Overclocking options - Choose a clock speed of 33, 48 or 57 MHz
• FAT32 filesystem for easy image transfer
• MBR partition-mapped images for >4GB disks
• Disc catalog allows rotating through CD images without rebooting
• Easy firmware updates via SD card

Performance on a PowerMac 6100 with firmware v1.1.0 and 57MHz overclock:

MacSD ships with the Commander application, which easily moves files from the FAT32-formatted SD card, to your Mac. This is a convenient way to move downloads to older Macs without networking or emulators:

Thanks to @JDW, who did an excellent and thorough review of MacSD, demonstrating installation, configuration and more:

 

[JDW]

Reads up to 3.2MB/s, Writes up to 2.5MB/s (PowerMac 6100, 57MHz clock speed)

I'm big on performance when it comes to SCSI to SD solutions, and MacSD is really quite incredible when it comes to that. Plus you get all the other great features too, which is amazing.

After my SE Reloaded video series concludes, I intend to revisit MacSD (and the new firmware) and also add BlueSCSI to the mix due to its popularity, and maybe even add the black-colored BlueSCSI F4 too (if I decide to buy one). I will exclude SCSI2SD and RaSCSI, but I think that's okay, especially since I don't have those anyway.

MacSD also has multiple ways to Terminate, which makes it a very flexible device!

 

[eric]

Looks like a great product! I have a few technical questions if you don't mind.

1 - What are the multiple ways to terminate? It looks like there's 2 resistor nets connected to vcc - so I'm assuming they're 110ohm for active termination? (just guessing from the photo, please correct me)

2 - Building images on the fly - do you create the partition map and then map a specific driver to the "bare" hfs volumes? If so what driver do you use (since they are so picky mixing them and can be written to/changed)

3 - The Commander app - does it use some vendor commands to transfer back and forth? I've been poking around at sending/receiving data over the scsi bus with a thinkc program, but I'm not a 68k dev

Thanks, and I hope you don't mind the technical questions since it's in "The Lab"

 

[YMK]

Hi Eric. For #1, the resistors are 330 Ohm and may be connected to VCC or GND.

#2 and #3 are proprietary, but on the latter, yes the commands are vendor specific.

MacSD is a hardware (and firmware, and software) project, so I posted here. However, it is not an open source project and I saw no such requirement in the forum description.

I appreciate the interest, but MacSD is imitated enough as is.

 

[eric]

Hi Eric. For #1, the resistors are 330 Ohm and may be connected to VCC or GND.

Ahh ok, so what are the multiple options for termination?

However, it is not an open source project and I saw no such requirement in the forum description.

There is not, of course. I was just curious how it worked.

 

[YMK]

Ahh ok, so what are the multiple options for termination?

They are pull-up (resistors to VCC), pull-down (resistors to ground) and FPT (resistors not installed).

 

[JDW]

They are pull-up (resistors to VCC), pull-down (resistors to ground) and FPT (resistors not installed).

Where FTP stands for Forced Perfect Termination, using diode clamps. I wanted to explain that because I often need help with acronyms!

In my first video on MacSD, I mention the 3 Termination methods not only because MacSD offers all three but because there are cases when one would work but the others not, mostly when you have another SCSI device connected, such as an internal drive. I have drives with resistor blocks on them, and others which allow you to enable active termination by changing a jumper. It's all a part of that "SCSI voodoo" people often talk about. It's not really voodoo but just a semi-complex topic, at least when you compare it to FireWire or USB which eliminate all the SCSI-related bothersome things like termination and SCSI ID conflicts.

My MacSD video also mentions Key Features, along with Composite images (which are unique to MacSD), and Configuration. As is true of all my videos, you will find a full Index that can help anyone jump to the spot that interest them.

I edited my previous post to clarify that the F4 is not "BlackSCSI" but rather a black colored version of "BlueSCSI." (My new wording is "black-colored BlueSCSI".) Sorry if my previous wording was confusing, but my brain tends to think in terms of the PCB color whenever BlueSCSI is concerned. The F4 is not only black in color, but it also uses the Black Pill instead of the Blue Pill, which is partly why it can achieve different levels of performance, as described on the F4 website. The newer F4 XCVR edition also adds "transceivers," which seem aid in compatibility. I've not tested the F4 yet, but the creator, Androda, very kindly spent a lot of time answering my many questions privately by email over the past week, and I appreciate that very much!

Lastly, the reason I intend to make mention of MacSD and BlueSCSI in that future video (which should include the F4 too) is because I wish to demonstrate that I am not going into this with intense bias, although it's not possible to eliminate bias entirely. I am very open about being big on performance. (Who overclocks a Color Classic Mystic to 50MHz if they don't care about performance, right?) Each of the aforementioned SCSI to SD products has its own merits, and pricing varies quite a bit too. Basically, my future video would show my observations about the products, which in turn may help people make a more informed buying decision. Helping others be informed is what my channel is all about. I think each of the products mentioned have their place in the market, and would-be buyers are indeed blessed in having so many options to choose from.

What I have said might be construed as having somewhat hijacked this thread. I should have perhaps kept my comments more focused on MacSD, excluding any comments on other products. I apologize for that. I just wanted to explain my future video plans while also keeping MacSD at the heart of what I wrote in order to stay fairly on-topic. No offense intended to YMK or any of the parties involved.

 

[YMK]

MacSD firmware v2.0.0 is now available.

This major release was in development for most of 2022 and adds more features than any other to date. A summary of new features:

MIDI interface and routing system

• MIDI over SCSI using custom OMS driver (System 7+)
• Works with OMS, QuickTime and MIDI Manager
• MIDI over USB (bidirectional)
• MIDI over MPU-401/SoundBlaster gameport or standard DIN ports (bidirectional)
• MIDI to internal synthesizer
• Add a MIDI output port to your Mac without tying up a serial port.

MIDI synthesizer

• Sample-based synthesis
• 32KHz, 13.75-bit stereo
• Up to 32 voice polyphony
• General MIDI instruments
• Three reverb settings
• Variable 3D depth effect
• 13 drum kits, 500+ drums in total
• Functions as wavetable add-on for SoundBlaster cards
• Replaces QuickTime Musical Instruments, freeing up CPU cycles and improving music quality.

Temperature sensors

• Connect up to 8 sensors through the expansion port

PWM fan control

• Configure up to two PWM-enabled fans for fixed or temperature-based speed control

USB interface

• Configure and monitor MIDI routing, synthesizer, temperatures, fan speeds, CD-ROM changer queue and more.
• Non-interactive and terminal-based control.
• Send MIDI data to a soft synth running on a Raspberry Pi, etc.
• Standard MIDI and serial interfaces require no special driver.

MacSD's synthesizer providing the soundtrack for Gabriel Knight on an LC475, through MIDI manager and OMS:

Playing some 80s and 90s MIDI files through Arnold's MIDI player and OMS:

Works great with vintage PCs too:

Installed in an LC475, controlling fan speed based on CPU temperature...


...and also driving a MIDI output port. The LED indicates MIDI activity and the pink line out jack combines MacSD's CD/synthesizer audio output with the LC475's audio:



Special thanks:
@JDW - For featuring MacSD in his excellent videos and testing.
@Crutch and cheesestraws of 68kmla - For assistance with 68K driver development.

 

[bakkus]

That's an impressive feature set for sure!
I might have a machine or two in need of one of these.

One thing caught my eye: Talk to me about that fan you have in the LC475?

 

[YMK]

One thing caught my eye: Talk to me about that fan you have in the LC475?

It's a Noctua NF-A6x25 with a Dremel treatment. It's 10mm thicker than the stock fan so cutting some of the frame out allows the air to move sideways.

 

[retr01]

It's a Noctua NF-A6x25 with a Dremel treatment. It's 10mm thicker than the stock fan so cutting some of the frame out allows the air to move sideways.

That is awesome, @YMK! Can you clarify how you got a huge heat sink on the 040?

 

[YMK]

That is awesome, @YMK! Can you clarify how you got a huge heat sink on the 040?

A combination of thermal paste and glue. I did clean the excess off after this picture:



It's running fairly cool:

https://www.amazon.com/gp/product/B07PLPBY5Z

 

[retr01]

Cool, @YMK. Is it needed to get 100 mm long? Will a normal 40 mm do fine? Does the longer one 100 mm provide more heat absorption than 40 mm?

Is the sensor from the fan picked up by MacSD?

 

[YMK]

Cool, @YMK. Is it needed to get 100 mm long? Will a normal 40 mm do fine? Does the longer one 100 mm provide more heat absorption than 40 mm?

Is the sensor from the fan picked up by MacSD?

There's a 50x50mm option that should work fine, given most 040s don't need a heatsink at all.

I expect the 100mm version to do better. The copper spreads heat along the whole length well.

MacSD is reading temperature from a thermistor underneath the heatsink and modifies fan speed based on that.

It doesn't read fan RPM currently.

 

[JDW]

A combination of thermal paste and glue. I did clean the excess off after this picture:

View attachment 9217View attachment 9218

It's running fairly cool:

View attachment 9219

https://www.amazon.com/gp/product/B07PLPBY5Z

What brand and model number of glue and thermal paste were used?

Can you break the glue in order to change the thermal paste in the future?

The reason I ask questions is because I have been pondering a pure copper heatsink for better cooling for my highly overclocked 68040 in my Color Classic Mystic — which MacSD works great with, by the way.

The features set of version 2.0 firmware for MacSD is absolutely incredible. MacSD already had an amazing feature that other products couldn’t touch, but this takes it to a new level.

 

[YMK]

The glue can be broken if you put the CPU in the freezer for a while. Then scrape off any residue with a razor.

The recommended drying time is 24 hours, so I kept it clamped for that long.

Thermal glue
Thermal paste

The 100mm version should work great on your 040, especially if you can center it better than I could on the LC475.

Thanks for the kind words. They're especially appreciated, coming from someone of your experience.

 

[retr01]

There's a 50x50mm option that should work fine, given most 040s don't need a heatsink at all.

I expect the 100mm version to do better. The copper spreads heat along the whole length well.

cool!

MacSD is reading temperature from a thermistor underneath the heatsink and modifies fan speed based on that.

It doesn't read fan RPM currently.

Ah. Will that RPM reading be added later? What about LEDs, seperate screen, or an app on the Mac to register temperature, cpu frequency, voltage, data transfer rate, etc.?

I treat 68k Macs like classic cars and in cars, more information like on the left side between the driver door and windshield is really cool.

 

[YMK]

Will that RPM reading be added later?

It's possible, but I don't plan on it. Speed vs duty cycle is fairly constant for a given fan if it's working properly.

What about LEDs

What kind of LEDs? The eight on-board LEDs can be duplicated through the expansion port.

seperate screen

No plans for this.

or an app on the Mac to register temperature

This is likely.

cpu frequency, voltage

Outside of the scope of what the board can measure.

data transfer rate

Can do, but probably won't. People interested in that typically run benchmarks.

 

[retr01]

It's a Noctua NF-A6x25 with a Dremel treatment. It's 10mm thicker than the stock fan so cutting some of the frame out allows the air to move sideways.

Like changing the storm pattern from tornado 🌪 to hurricane ? I have a couple of questions about that.

• When the top frame of the Noctua fan is removed, does that compromise the design and increase vibration and noise?
• Since the air pattern was changed from drawing the air out through the bottom of the case to spreading the air sideways causing the air to exit through various opening of the case, does that reduce the efficiency of moving warmer air out of the case?

 

[YMK]

When the top frame of the Noctua fan is removed, does that compromise the design and increase vibration and noise?

No. I think having one spoke instead of four reduces potential for turbulence and noise.

Also the single remaining spoke makes for a more compliant suspension for the motor and might reduce vibration to the chassis.

If it ends up sagging over time, I'll have to correct that.

Cutting away the fan grille on the floor shield of the case could reduce noise further, but it's barely audible to begin with.

Since the air pattern was changed from drawing the air out through the bottom of the case to spreading the air sideways causing the air to exit through various opening of the case, does that reduce the efficiency of moving warmer air out of the case?

The air still takes the same path in and out of the case. It just isn't firing straight up into the cover as it did before the mod.