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MacSD - new SCSI SD card emulation tool

ymk

Well-known member
If I'm not seriously mistaken, a typical T1-3/4 LED, red, uses about 20mA when operating on a 100% duty cycle (or...just on). I don't have it immediately available but if I'm recalling correctly green, blue and especially white require more to reach full brightness. Now the LEDs used in 1989 were not particularly bright, and were probably not driven at full power either, but I couldn't help but notice that 1mA is probably barely enough to forward-bias the LED.


You are mostly correct.  I would not say an LED uses 20mA, but that it tolerates that current.  It emits light with far less current, but as you've mentioned, a 1989 LED is less efficient than what is available today.  The LED code was overhauled for v0.8.0.  Maximum external LED drive is 3.3v through a 220 Ohm resistor at 9.7% duty cycle.

 
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Cory5412

Daring Pioneer of the Future
Staff member
I'm curious about this. Apple says that 7.5.2+ supports up to 2TiB. Is their KB article an error?


Doing so requires SCSI Manager 4.3, which is present in the '040 Macs. I don't know about 7.5 in particular, although 7.6 has been seen doing 2TB with SATA cards. There's, uh, no real reason why you couldn't do the same with 7.5, although I'll admit I'd personally rather run 7.6.1 on any PCI PowerMac that'll run it than 7.5.

Here's another overview:





So, SCSI Manager 4.3 on an '040 Mac is, as far as I can tell, required for above-4GB volumes. I've seen some discussion about getting >4GB on '030s but I don't know where it went. This is some kind of hardware limitation because it applies even to 8.1, and of course because plain-HFS can itself go up to 2TB. (Just: the files will be very big if you make a 2TB plain HFS volume.)

I've heard varying reports of the stability of big volumes in 7.5.2, but 7.5.3 or 7.5.5 should do it fine.

That discussion is best led by people who have actually used the device, or at least bothered to read the documentation before speculating.


I'm excited to hear more from them.

Over the past several years, we've seen several different round-ups on the available options. One that Fizzbin wrote a year ago is linked in the lead post to this thread. I'm sure it won't be long until someone who has a few of the different devices posts another write-up or round of benchmarks.

I'll let you know about a vendor account.


I'm coordinating with my co-admin to decide on where vendor accounts should "go". Announcements will be made if the policies change from what's currently on the rules page.

 

cheesestraws

Well-known member
I've sold to non-Mac users and will continue to.  Don't concern yourself with it.
Well, given the way you've marketed it, at least on the web/eBay it's not an unreasonable assumption that it's quite tightly focussed.  If that isn't your intent, it might be good to tweak your prose slightly.  That said, I'm intending to test drive it in other SCSI-based machines (assuming I can reclaim my most interesting one from someone else's garage...) so at least in my case your marketing hasn't done much harm :) .

(Parenthetically, I do find it very interesting that "toy" is taken as a pejorative (not just here, in lots of places—this is not personal in the least!), rather than just a label for a way of using something.  In my Ludicrously Overengineered Home Network I have some exquisitely engineered electronics (and in one specific bit, optics).  Are they toys?  In my context, yup.  But they're such good toys precisely because they're so well-built.  Perhaps "luxury" is a less loaded term here, but I think it's such a shame that adults are so ashamed of wanting to play and learn that being told that one has made a good toy can feel like an insult...)

That discussion is best led by people who have actually used the device


I'm excited to hear more from them.
Mine should be arriving today (?).  If my neurochemistry decides to behave next week I'm planning to do a comparison (I have scsi2sd v5 and v6 here to compare against).  Though, as I'm sure you're used to by now, my priorities are very much flexibility, ease of use and "having a quiet life" rather than raw performance, so while I will benchmark, if you want to do serious benchmark snooping you will probably have to talk someone else into it.  Given the documentation, I have high hopes :) .

 

cheesestraws

Well-known member
@ymk it just arrived safe and sound :) .  Looks really nice.  Impressed by the physical quality of it.  Won't have time to seriously play with it until next week, but wanted you to know it had got here.

 

ymk

Well-known member
I am still observing some freezing which happens to be occurring with HyperCard across 3 different CD images, but I am not sure if its an image file issue or the hardware (MacSD or otherwise).
I had the same hard lockup running HyperCard from that image on my Centris 610 with System 7.5.5.  There were no SCSI faults.

I used the Centris to copy the contents of that CD image to a 2GB HDD image.  I then switched the boot drive in macsd.ini to Realitystorm's 6.0.8 image, put the card in my Classic and the stack ran fine.  It appears to be a software issue.

bmug.jpg

 

Byte Knight

Well-known member
This is a very cool device!  I put a MacHD in an external HD case so I can use it with my vintage Macs and IIgs.  I've got a RaSCSI too, for which the price is definitely right, but it's nice not having to wait for the Pi to boot up before you turn your computer on, and it's also nice to be able to hook up an HD activity light.

 

LaPorta

Well-known member
Question: how configurable is this thing via a modern Mac rather than a PC? How's it been going for everyone?

 

Byte Knight

Well-known member
Question: how configurable is this thing via a modern Mac rather than a PC? How's it been going for everyone?
Everything is configurable by popping the MacSD's SD card into your modern computer and editing the macsd.ini text file, so no difference.  An SD extension cable is highly recommended...

 

CC_333

Well-known member
Just got caught up with this thread, and I must say it's an exciting development!

With regard to the discussion between @ymk and @Cory5412 about the simplicity of MacSD vs. SCSI2SD w/re: implementing >4 GB partition support and such, my take on it is that basically, there's no reason why that's a bad thing for simplicity.  Perhaps it complicates configuration a bit for those who choose to use it, but it's implemented as a more advanced feature anyway, intended for users with more advanced needs, and to the best of my understanding, it doesn't interfere with MacSD's core feature set, which indeed appears to be quite simple to configure.  Therefore, the fact that it *can* support >4GB partitions doesn't make it any harder to use if all one wants is a plain old =<4GB image file mapped from a standard FAT32 partition.

And regarding the SCSI Manager 4.3 thing, my understanding is that primarily affects boot-ability, yes?  In that case, this can still see some use on an '030-based Mac, such as, for example, a Pro Tools rig based on a Mac IIfx, because uncompressed audio files can get pretty big.

c

 

CC_333

Well-known member
@cheesestraws I did read your write up, and it is indeed very nice!

Depending on my budget, I may be interested in getting one at some point!

I have been interested in getting a SCSI2SD for some time now, but due to their apparently recalcitrant nature and my chronically underfunded budget, I've held back because I still have enough original hard drives in working order that I'm not super rushed to get one.

c

 
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ymk

Well-known member
Firmware v0.10.0 is now available and adds a new "composite" device type.  This allows the use of multiple partition images (floppy, MiniVMac, etc) under a single SCSI ID.  ProDOS and FAT disks work with the appropriate extensions.  Once a directory is bound to a SCSI ID in the config file, images added to that directory are included automatically.  Up to 60 images total may be mounted.

This update also fixes issues noted by @cheesestraws:

  • Partition type 0x0B is accepted in addition to 0x0C (except for firmware updates).
  • Filenames in the config file are now case insensitive to avoid 8.3 problems.

floppyimg.png

 

cheesestraws

Well-known member
Firmware v0.10.0 is now available and adds a new "composite" device type.  This allows the use of multiple partition images (floppy, MiniVMac, etc) under a single SCSI ID.  ProDOS and FAT disks work with the appropriate extensions.  Once a directory is bound to a SCSI ID in the config file, images added to that directory are included automatically.  Up to 60 images total may be mounted.


Well, I know what my techy thing to do this weekend is now! :)

 
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