Announcing ZuluSCSI - A file-based SCSI device emulator

[rjkucia]

To answer some of your questions:

• The Mac Plus has a weird/non-standard SCSI implementation that doesn't provide enough power for devices, so I believe you do need external power for all SCSI devices
• The Mac Plus will work great with System 6. Depending on how much RAM it has, System 7 might work okay, but generally 6 will be a more pleasant experience.
• Here are some good pre-made images: https://macintoshgarden.org/apps/rascsi-reloaded The RaSCSI, ZuluSCSI, and BlueSCSI all use the same types of images, so they're interchangeable.
• The Mac Plus does not have internal SCSI, as far as I know, so you'll need to use the external DB25. It looks like ZuluSCSI has an empty header for that, so you'll have to add it (or purchase one that has it pre-installed). You can attach two DB25 SCSI devices with a cable or a gender changer, such as this one: https://samplerzone.com/products/scsi-db25-db25-gender-changer I'm not sure how well that will mechanically fit in your setup, though.

 

[rabbitholecomputing]

To answer some of your questions:

• The Mac Plus has a weird/non-standard SCSI implementation that doesn't provide enough power for devices, so I believe you do need external power for all SCSI devices

It's not that it doesn't provide "enough" power. This is not an accurate representation of the situation. The Mac Plus simply does not provide any SCSI termination power, unless you add a diode to the location on the Mac Plus logic board where Apple chose to omit it, presumably out of an overabundance of caution. Nearly all other desktop Macs provide SCSI termination power.

 

[rjkucia]

It's not that it doesn't provide "enough" power. This is not an accurate representation of the situation. The Mac Plus simply does not provide any SCSI termination power, unless you add a diode to the location on the Mac Plus logic board where Apple chose to omit it, presumably out of an overabundance of caution. Nearly all other desktop Macs provide SCSI termination power.

You're correct - I should have spoken more accurately/confidently.

 

[MattBranth]

• The Mac Plus will work great with System 6. Depending on how much RAM it has, System 7 might work okay, but generally 6 will be a more pleasant experience.
• Here are some good pre-made images: https://macintoshgarden.org/apps/rascsi-reloaded The RaSCSI, ZuluSCSI, and BlueSCSI all use the same types of images, so they're interchangeable.

Ok so I just have to download RaSCSI-Boot-6.0.8.hda for example and to rename it HD0.hda and copy it in the SDCard.
When I switch on the mac it will boot on this emulated HD ? I wonder how the mac makes the difference between a (simulated) bootable disk and a (simulated) disk containing a software...

• The Mac Plus does not have internal SCSI, as far as I know, so you'll need to use the external DB25. It looks like ZuluSCSI has an empty header for that, so you'll have to add it (or purchase one that has it pre-installed). You can attach two DB25 SCSI devices with a cable or a gender changer, such as this one: https://samplerzone.com/products/scsi-db25-db25-gender-changer I'm not sure how well that will mechanically fit in your setup, though.

I think that the ZuluSCSI Mini I bought got a DB25 male connection : https://amigakit.amiga.store/zuluscsi-mini-adapter-p-91288.html

It's not that it doesn't provide "enough" power. This is not an accurate representation of the situation. The Mac Plus simply does not provide any SCSI termination power, unless you add a diode to the location on the Mac Plus logic board where Apple chose to omit it, presumably out of an overabundance of caution. Nearly all other desktop Macs provide SCSI termination power.

Ok I will try this modification.

I have other questions:
- If I want to use Mac Paint, I just have to download, for example, this image : https://macintoshgarden.org/apps/macpaint and to rename it HD1.hda. Then I click on the SCSI 1 icon on the Mac finder ?
- Is it possible to get a simulated blank HD to save data files (images, texts) or to transfert data file (images, texts) from a modern windows laptop to the mac plus and vice versa ?

Thks for helping me! I'm a beginer (re)using old Macs. In fact, I used a Mac IICI as a child, but unfortunately I forgot all the logic of this generation of Macs...

 

[rabbitholecomputing]

Ok so I just have to download RaSCSI-Boot-6.0.8.hda for example and to rename it HD0.hda and copy it in the SDCard.
When I switch on the mac it will boot on this emulated HD ? I wonder how the mac makes the difference between a (simulated) bootable disk and a (simulated) disk containing a software...

It doesn't, it can't tell the difference. That's the whole point/goal.

I have other questions:
- If I want to use Mac Paint, I just have to download, for example, this image : https://macintoshgarden.org/apps/macpaint and to rename it HD1.hda. Then I click on the SCSI 1 icon on the Mac finder ?

There won't be a "SCSI 1 icon" per se, the Macintosh will simply see a volume, and, assuming it's formatted and partitioned correctly, Finder will show the name of the volume on the desktop.

- Is it possible to get a simulated blank HD to save data files (images, texts) or to transfer data file (images, texts) from a modern windows laptop to the mac plus and vice versa ?

Yes, but you have to know what you're doing. I'd recommend asking these questions in a new, non-ZuluSCSI-specific thread. Welcome to the forum!

 

[MattBranth]

Yes, but you have to know what you're doing. I'd recommend asking these questions in a new, non-ZuluSCSI-specific thread. Welcome to the forum!

I can do that but in which section of the forum ?

Other question :
- Is it possible to make a big HD image containing multiple software and "load" it onto the mac? Is there a utility to do this on a Windows computer?

 

[Skate323k137]

I can do that but in which section of the forum ?

Other question :
- Is it possible to make a big HD image containing multiple software and "load" it onto the mac? Is there a utility to do this on a Windows computer?

I would open it under the section for the type of machine you're using (68K, PPC, etc) perhaps.

There are windows utilities for working with Macintosh volumes, yes. I personally use macs more nowadays and use Basilisk II to manage disk contents before putting the image on a SCSI emulator such as the ZuluSCSI.

Welcome aboard.

 

[rabbitholecomputing]

- Is it possible to make a big HD image containing multiple software and "load" it onto the mac? Is there a utility to do this on a Windows computer?

Yes, you can do this via Basilisk on Windows as well. There are plenty of videos and tutorials online, if you Google it, but someone here may be able to provide a recommended link/guide.

 

[MattBranth]

Hi! I have a problem booting my Mac Plus using a mini ZuluSCSI card.

1) The first problem is that I can't update the firmware. However, I followed the instructions on this official page
- I download the ZuluSCSIv1_0-1.1.1-a18a7b8.bin file in my fat32 SD card
- I rename it ZuluSCSIv1_0_.bin
- I power the Zulu card with an USB cable
=> The result is that the LED flashes three times (= No images found on SD card ?) and nothing happens. So I gave up on updating the firmware.

2) I can't boot my Mac Plus, my modus operandi is as follows :
- I load on the SD card
* the zuluscsi.ni file found on the repo

[SCSI]
# Settings that apply to all devices
Debug = 0   # Same effect as DIPSW2, enables verbose log messages
SelectionDelay = 0   # Millisecond delay after selection, 255 = automatic, 0 = no delay
PhyMode = 0   # 0: Best available  1: PIO  2: DMA_TIMER  3: GREENPAK_PIO   4: GREENPAK_DMA
#Dir = "/"   # Optionally look for image files in subdirectory
#Dir2 = "/images"  # Multiple directories can be specified Dir1...Dir9

# Settings that can be needed for compatibility with some hosts
Quirks = 0   # 0: Standard, 1: Apple, 2: OMTI, 4: Xebec, 8: VMS
EnableUnitAttention = 0 # Post UNIT_ATTENTION status on power-on or SD card hotplug
EnableSCSI2 = 1 # Enable faster speeds of SCSI2
EnableSelLatch = 0 # For Philips P2000C and other devices that release SEL signal before BSY
MapLunsToIDs = 0 # For Philips P2000C simulate multiple LUNs
MaxSyncSpeed = 10 # Set to 5 or 10 to enable synchronous SCSI mode, 0 to disable

# Settings that can be specified either per-device or for all devices.
#Vendor = "QUANTUM"
#Product = "FIREBALL1"
#Version = "1.0"
#Serial = "0123456789ABCDEF"
#Type = 0     # 0: Fixed, 1: Removable, 2: Optical, 3: Floppy, 4: Mag-optical, 5: Tape
#TypeModifier = 0  # Affects only INQUIRY response
#SectorsPerTrack = 63
#HeadsPerCylinder = 255
#RightAlignStrings = 0 # Right-align SCSI vendor / product strings, defaults on if Quirks = 1
#PrefetchBytes = 8192 # Maximum number of bytes to prefetch after a read request, 0 to disable

# Settings can be overridden for individual devices.
[SCSI2]
Product = "Disk with ID2"

[SCSI5]
Product = "CD-ROM Drive"
Type = 2
# If IMG0..IMG9 are specified, they are cycled after each CD eject command.
#IMG0 = FirstCD.iso
#IMG1 = SecondCD.iso

# Raw sector range from SD card can be passed through
# Format is RAW:first_sector:last_sector where sector numbers can be decimal or hex.
# If end sector is beyond end of SD card, it will be adjusted automatically.
# [SCSI4]
# IMG0 = RAW:0x00000000:0xFFFFFFFF # Whole SD card

As read in this thread, I modified the SelectionDelay to "0" because I'm using a Mac Plus.

* The RaSCSI-Boot-6.0.8.hda disk image containing the system 6.0.8 found here
I rename it HD0.hda

=> When I power my Mac Plus (I made the Diode Mod), the LED flashes three times (= No images found on SD card ?) after a short period of time, the LED blinks for about 1 minute, then it stays on continuously. The Mac doesn't boot, it displays the famous question mark disk.

Any ideas ?

 

[MattBranth]

I changed the microSD card, and it works now !!!

 

[dankcomputing]

Just bought a ZuluSCSI RP2040 and immediately ran into a bug that's not present on the older hardware version - SD cards smaller than 4GB won't work. I tried a whole bunch of 2GB cards that I knew worked on the old hardware and got the 5-blink error message every time. Tried a 4 and 16GB card and those worked right away.

 

[rabbitholecomputing]

Just bought a ZuluSCSI RP2040 and immediately ran into a bug that's not present on the older hardware version - SD cards smaller than 4GB won't work. I tried a whole bunch of 2GB cards that I knew worked on the old hardware and got the 5-blink error message every time. Tried a 4 and 16GB card and those worked right away.

Hi, this is not entirely correct. We definitely have 4GB SD cards that work fine with the ZuluSCSI RP2040. Most 4GB SD cards don't work with ZuluSCSI V1.1 either. The reason for this limitation is the silicon in the SDIO controller itself, which does not support SD cards that do not adhere to a specific revision of the SD card specification. It gets really, really messy. So much so, that we don't recommend SD cards smaller than 8GB with any version of ZuluSCSI, just because of how messy it can be. We spent quite some time tracking down and understanding this bug, which is really a hardware limitation that we can't do anything about, at least in the case of ZuluSCSI V1.1.

If you'd be willing to share specifics with us about the SD cards in question you're having trouble with (or even the cards themselves), that would be really helpful for us, as it's entirely possible we have a similar situation on the RP2040 side, that we're not aware of. Both ZuluSCSI V1.1 and ZuluSCSI RP2040 use SDIO (not SPI) as the communications protocol between the microcontroller and the SD card itself. This is necessary for the higher read speeds to be achieved.

 

[dankcomputing]

Oh the 4GB (brand is Team) is working fine. I also tried an 8GB (Kingston) and that works too. The problem cards were all 2GB. Brands were Kingston (have 4 of the exact same model here) and one PNY.

I also have a Toshiba card that simply locks up both versions of the ZuluSCSI (doesn't even give any error blinks) but works fine in the SCSI2SD.

Maybe the problem is SD vs. SDHC?

 

[rabbitholecomputing]

Yes, the 2GB to 4GB era is when SDHC became standardized, but there was a period of years where not all cards were compliant. The SDHC card specification was released sixteen years ago, back in 2006. Both ZuluSCSI RP2040 and ZuluSCSI V1.1 use SDIO for communication with SD cards. All SCSI2SD V5.x variants, as well as MacSD and BlueSCSI, use SPI as the communication protocol between the microcontroller and SD cards. SPI is simpler, one-bit protocol, which almost every modern microcontroller supports, whereas SDIO isn't supported by a lot of lower-cost microcontrollers. In the case of ZuluSCSI RP2040, we're making use of one of its special-purpose PIO controllers, to implement SDIO, as the microcontroller doesn't support it in a hardware silicon block, like the GD32F205 MCU in the ZuluSCSI V1.1 does.

 

[ScooberDiver]

Does anyone have any experience with (or has tips for) making a floppy disk image work with Zulu? I haven't found anyone mentioning it on the WWW but the docs do mention support of SCSI floppy drives. I'm booting from a hard disk image fine on my Zulu but the two floppy images I tried are not showing up. They don't automount and Lido sees them but says they are not a Macintosh disk so I can't manually mount them in there. The floppy images work fine if I write them to a real 1.4MB floppy using WinImage on a PC and put into a 68K Mac. The floppy images are named fd2.img and fd3.dsk and I also tried forcing device type in zuluscsi.ini. SCSIProbe shows them as Teac SCSI floppy drives.
[scsi 2]
type = 3
[scsi 3]
type = 3

Thank you

 

[rabbitholecomputing]

@ScooberDiver The Macintosh Toolbox ROM has a hard-coded assumption/requirement that every bootable SCSI device must have an Apple Partition Map. Since HFS floppies do not contain a partition map, and instead contain only the raw HFS filesystem information itself, you cannot use an unmodified floppy image to boot via SCSI. This is an unfortunate technical limitation of the Mac, not ZuluSCSI. The Macintosh ROM refuses to boot from an emulated SCSI floppy drive, due to this machine-side limitation.

 

[ScooberDiver]

@rabbitholecomputing Thanks. I'm fine with that. Do you know why the floppy disks might not be showing up after I've booted from Zulu's hd0.img ? Thanks

 

[rabbitholecomputing]

@ScooberDiver You'll need to examine the contents of your zululog.txt file, which will likely shed light on what's going on there.

 

[tcole]

Possibly dumb question. I have a ZuluSCSI RP2040 in a Quadra 700 and it’s working great. I’m running System 7.5.5. And the ZuluSCSI has firmware 1.1.5.

I have the ZuluSCSI ini setup with a few ISOs and I see in the documentation that an Eject command is supppsed to cycle through them.

On cold boot the first ISO is mounted on the desktop. But on a reboot nothing is mounted.

But how do I send the eject command when the ISO isn’t mounted on the desktop?

 

[cheesestraws]

But how do I send the eject command when the ISO isn’t mounted on the desktop?

You could try using "Eject": it's a PD program which I made a 68k build of it some time ago, which is available here: https://macintoshgarden.org/apps/eject-version-101