WarpSE: 25 MHz 68HC000-based accelerator for Mac SE

[JDW]

I went through all the documentation I could find on the IWM and the SWIM...
I'm meant to be finalising the 475 overclock code and doing testing on the 6200 and 6100... but I might do some digging if I have time.

I wish to humbly thank you for all your hard work on both of those topics!


By the way, this is the 1.44MB drive I've been using (pulled from one of my SE/30 machines) in conjunction with my SE Reloaded motherboard and IWM chip:

This evening, I booted into System 7.1 and launched MacTest SE and clicked the Options menu and chose Test Selections. I unticked everything but Disk Drives : Lower Drive (where I have the 1.44MB drive connected). I then proceeded to do the tests. It first asks for a blank 800K disk. Those tests passed. It then asks for a blank 1.44MB disk. Those tests passed as well. I knew they would pass based on my previous testing, but it's still nice to see that what I am experience is not a crazy fluke. It's reality.

I also ran the disk tests using Apple Personal Diagnostics v.1.1.3. It recognizes my drive as being a 1.44MB type. And when running the disk tests, if I insert a blank (but formatted) 800K disk, it will run and pass the tests. And if I then put in a blank (but formatted) 1.44MB disk, it also runs and passes the tests.

I plan to test my stock SE motherboard (which also has an IWM chip in it) tomorrow. If it works on that motherboard too, then would it really be two separate cases of a failed SWIM used as an IWM?

Also, it's important to remember that I can do everything I want with 1.44MB disks EXCEPT boot. It won't boot from 1.44MB disks (only 800K or 400K). But reads/writes and formatting on 1.44MB disks all work great.

If I can get my order filled with Kay Koba this week, and if he ships this week, it will probably arrive this week too (since we're both in Japan), and then I can test a SWIM, finally!

@Zane Kaminski
Putting 3 different ROMs on WarpSE will be simply outstanding!

 

[Zane Kaminski]

@JDW does your "SWIM" work with a Floppy Emu? I tried in my IWM-equipped SE with the WarpSE on the external connector but unfortunately it did not work.

 

[JDW]

@JDW does your "SWIM" work with a Floppy Emu? I tried in my IWM-equipped SE with the WarpSE on the external connector but unfortunately it did not work.

Holy cow, Zane! That test produced an unexpectedly great result for me, using my Model B FloppyEMU:

1. I booted from my BlueSCSI with WarpSE enabled (SE Reloaded motherboard). My FloppyEMU was connected externally.
2. I have a 1.44MB virtual floppy on my FEMU which has a bootable System 6 System Folder, so I rebooted, and quickly selected that 1.44MB virtual disk. Guess what? It booted!
3. At the Desktop, I put in a real 1.44MB floppy into the internal 1.44MB disk drive (connected to the LOWER ribbon cable connector on the motherboard), and I copied the contents of that virtual boot floppy to the real 1.44MB floppy. The copy succeeded.
4. I then restarted the SE and booted from the real 1.44MB disk!
5. I then shutdown, disconnected my FEMU. Then tried to boot from the real floppy again. It booted just fine.
6. I then shutdown, pressed INTERRUPT, then powered on (stock 8MHz) mode. It ejected my 1.44MB floppy and would not boot from it.

So why I could not boot from my 1.44MB disk during my tests at the office a few days ago is unknown, but it's booting from the internal 1.44MB drive now!

And you saw the markings on my IWM chip. Those "markings" are indeed showing an IWM, but the chip itself seems to be acting like a SWIM.

What does everyone think now?

(Yes, I will do these tests again tomorrow at the office using my stock SE motherboard, which has its own IWM chip.)

 

[phipli]

Holy cow, Zane! That test produced an unexpectedly great result for me, using my Model B FloppyEMU:

1. I booted from my BlueSCSI with WarpSE enabled (SE Reloaded motherboard). My FloppyEMU was connected externally.
2. I have a 1.44MB virtual floppy on my FEMU which has a bootable System 6 System Folder, so I rebooted, and quickly selected that 1.44MB virtual disk. Guess what? It booted!
3. At the Desktop, I put in a real 1.44MB floppy into the internal 1.44MB disk drive (connected to the LOWER ribbon cable connector on the motherboard), and I copied the contents of that virtual boot floppy to the real 1.44MB floppy. The copy succeeded.
4. I then restarted the SE and booted from the real 1.44MB disk!
5. I then shutdown, disconnected my FEMU. Then tried to boot from the real floppy again. It booted just fine.

So why I could not boot from my 1.44MB disk during my tests at the office a few days ago is unknown, but it's booting from the internal 1.44MB drive now!

And you saw the markings on my IWM chip. Those "markings" are indeed showing an IWM, but the chip itself seems to be acting like a SWIM.

What does everyone think now?

(Yes, I will do these tests again tomorrow at the office using my stock SE motherboard, which has its own IWM chip.)

I think the chip is a SWIM chip and the situation is probably reasonably unusual.

Where did the chip come from? is there any chance at all that it might be repainted?

Alternatively, perhaps Apple were short of spare IWMs for stocks and so just marked some SWIMs as IWM.

I think the mystery here is why you have a perfectly normal SWIM labelled as an IWM, rather than that an IWM can read 1.4MB disks.


Edit-
Others of each type from the web :

and yours :

 

[JDW]

Where did the chip come from? is there any chance at all that it might be repainted?

As shown in my video here, it was @Kai Robinson who shipped me the original bad motherboard which had the IWM chip socketed on it. I moved that to the SE Reloaded board.

 

[phipli]

As shown in my video here, it was @Kai Robinson who shipped me the original bad motherboard which had the IWM chip socketed on it. I moved that to the SE Reloaded board.

Unless @Kai Robinson swapped it out for a UTSource part then, it looks like Apple were fitting stealth SWIMs to some (probably later - why do a new run of the older part) 800k SEs then.

I mean, it doesn't matter at all, they're functionally identical when used like that. You only noticed because you installed the WarpSE and a superdrive

 

[phipli]

Looking at the numbers on the chips above, I'm guessing the numbers left of the V are the date code. The last Edit : First number in the triplet must be the year logically based on what is there. So yours is a 1987 part.

I'll check mine.

 

[phipli]

Found some old photos of my 800k SE. The IWM is marked almost identically to yours. 47th week of 1987.

I'll try swapping it into my FDHD chassis at some point, and swapping the ROMs. See what I get. Actually, just swapping the floppy controllers is simpler.

For reference :

Sorry all these photos are vertical, I'd make an excuse, but its just laziness.

 

[Zane Kaminski]

About to purchase some oscillators for the WarpSE production run! We have maybe 50-100 50 MHz crystal oscillators (for 25 MHz CPU speed) in the GW company parts but since we're increasing the speed a bit they'll have to be reallocated to some other project. No big deal! Those 50 MHz oscillators were fine, some from Seiko Epson and some from YXC. However I'm eyeing the SiTime SiT2001B series MEMS oscillators. These are not a crystal but a microelectromechanical resonator built inside a microscopic vacuum chamber encased in a silicon chip, followed up by a programmable PLL that can give you any frequency you want. The SiT2001B series has great specs, is accurate up to 85 degC, and you can order it from SiTime in basically any frequency. It also comes in SOT-23-5 package. Sounds good! So I'm buying 500 of em in the ~51.8 MHz range (for 25.9 MHz CPU speed)

As for the overclocking board, I found it would be a bit too close to the MacSE's chassis, so I had to reduce the pin count in the overclocking header and also I will be specifying a 1.2mm thick board for both the WarpSE and the overclocking board, reducing height a little bit more. 1.6mm is the standard board thickness but memory SIMMs are usually 1.2mm thick and they're still quite sturdy. Altogether that should give a few more mm of clearance for the overclocking board. Plus a thinner board is better electrically and less board weight will mean less board sag in the machine.

Overclocking board will probably be made by JLCPCB and use regular crystal oscillators whereas I will personally be producing the WarpSEs using the MEMS oscillators. I've got enough to do already lol so taking that little board off my plate should be helpful.

 

[JDW]

@Zane Kaminski
Very impressive little oscillator based on my brief look at the Datasheet.

• This article presents a nice overview of the company, which seems to have been a spin-off from Bosch:
• This article talks about the trade-offs between MEMS and Crystal Oscillators.
• And this article takes the most critical look at MEMS vs. Quartz.

---

I tested WarpSE on my stock Apple SE motherboard this evening after work. I have my SE/30’s 1.44MB floppy drive still attached internally to the “LOWER” drive connector. And I have my Model B FloppyEMU attached externally.

All said, 1.44MB floppies don’t work with WarpSE enabled. Only 400K and 800K, as you would expect. I cannot boot from the 1.44MB floppy I made yesterday (which boots when my SE Reloaded board is used). And if I boot from my BlueSCSI, if I then insert my 1.44MB disk, I am asked to initialize it as 400K or 800K. Same is true when testing 1.44MB virtual disks on my FloppyEMU.

Here's a photo of the chips on my stock SE motherboard:

 

[Zane Kaminski]

We’re just about ready to get the final WarpSE boards made but there’s one last consideration that needs made. I fear that the overclocking board installed in the WarpSE will make the whole board stack too tall and hit the chassis. Reducing the board thickness helps a bit but it’s still not great. So I’m looking into lower-profile connectors.

@JDW Just wondering, does the 1.44M bootable floppy you made with your “IWM” boot in your system with a SWIM? And with the “real” SWIM and WarpSE, are 1.44M floppies working well including for boot?

 

[JDW]

@JDW Just wondering, does the 1.44M bootable floppy you made with your “IWM” boot in your system with a SWIM? And with the “real” SWIM and WarpSE, are 1.44M floppies working well including for boot?

I cannot answer that question until I receive the SWIM replacement from Kay Koba. Right now, I don’t have a SWIM chip to test.

 

[Kai Robinson]

As shown in my video here, it was @Kai Robinson who shipped me the original bad motherboard which had the IWM chip socketed on it. I moved that to the SE Reloaded board.

I can categorically deny any tampering!

Honestly, the board had maybe 30 mins of attention paid to it, before it was put back in the case and shipped off.

 

[JDW]

@Kai Robinson
Nobody else so far who has been using WarpSE has had the same result as me, so that IWM chip you shipped me could very well be unique in the world!

Later today, I will remove that “IWM” chip from my SE Reloaded motherboard and install it in the stock SE board to see what happens.

 

[Zane Kaminski]

I think I fixed the overclocking board's Z-height:

Now I'm using a 2.0mm pitch header instead of 2.54mm. It's much shorter as well. This amounts to a reduction of the board stack from like 14.5mm to under 9.5mm. Perfect, now there's no risk of collision with the chassis.

Just a few more fixes and improvements to the final WarpSE main board are required and then I can send it to fab. Basically I am doing a few last tricks to remove speed barriers to overclocking and also to save space in the CPLD.

 

[JDW]

Boy! I'm hoppin' mad at myself and deserve a real punch in the nose.

All this time, I've been sharing photos of my board taken in the past in this thread because I felt confident I never touched the chips after making my videos. But when using a lens this evening, I discovered that assumption was flat out wrong.

I actually have a SWIM chip socketed in my SE Reloaded board!

Yes, the whole freaking time!

I feel like a complete idiot. Well, I am, so it's more than a feeling.

Holy Freaking Cow!



My test reports to date when using SE Reloaded have been done with a SWIM installed. All testing with my stock Apple motherboard has been done with an IWM installed. Old ROMs are installed on both boards, but as we all know, WarpSE has the new SE ROMs onboard.

The implications of this are now clear:

1. With a SWIM and Old ROMs, you can only use 400K and 800K disks.
2. With a SWIM and New ROMs, you can of course use 1.44MB disks too.
3. Even with a SWIM installed, regardless of using OLD or NEW ROMs, you can boot into some of the oldest System Software available, including System 0.97 and Finder 1.0. That is true with or without WarpSE enabled.
4. The only System Software I cannot get to function correctly is System 0.85. The same is true of the Mac 128K Guided Tour disk because it uses System 0.85. The SE will boot with that System, but it will then lockup. This is true even with the Old ROMs and IWM chip, and with WarpSE disabled. My Mac 512K can boot into System 0.85 just fine, and there are no lockups. So I think System 0.85 is more tightly attached to the ROM code, which is why the SE has trouble with it. But hey, System 0.97 is pretty darned old, so it's not a big loss.

The presence of a SWIM will not prevent your SE from booting into very old versions of System Software.

This also makes me feel that SE owners would do well to upgrade to a SWIM and the 1.44MB SuperDrive, since it doesn't seem to have any kind of negative implications.

I did more testing with my SE Reloaded board, SWIM chip and with WarpSE enabled, booting off a real 1.44MB floppy in order to see what System Software will work:

BOOTING FROM a 1.44MB FLOPPY
1. System 6 and higher: boots fine
2. System 4.3 & Finder 6.0: boots fine
3. System 4.2 & Finder 6.0: boots fine
4. System 4.1 & Finder 6.0: boots fine
5. System 4.1 & Finder 5.5: boots fine
6. System 3.4 & Finder 6.1: boots fine
7. System 3.3 & Finder 5.5: boots fine
8. System 3.2 & Finder 5.3: boots fine
9. System 2.1 & Finder 5.0: boots fine
10. System 2.0 & Finder 4.1: boots fine
11. System 1.1 & Finder 1.1g: boots fine (MacPaint & MacWrite & Font Mover all worked fine, including saving and opening files)
12: System 0.97 & Finder 1.0: boots fine (all apps tested launched and worked fine)

Above and beyond those tests, I copied more than 800K to the 1.44MB floppy, and it still booted just fine. So this means you really can boot from pretty much any System Software you like and gain much more disk space too!

CAVEATS:
1. You can't format 1.44MB floppies while booted into an OS lower than System 6.
2. If you try to Erase Disk while booted into System 2.0, it won't even ask you about 400K or 800K, it will just do it, then crash. Your 1.44MB disk will then need reformatted under System 6.
3. I didn't test a lot of software, so there could be issues with some apps, especially when saving files.

 

[iPhil64]

Come on James, if you were an idiot, you would definitely not do so MANY tests, in depth, for the benefit of the whole community.
You forgot about the SWIM, that's all !

 

[phipli]

I actually have a SWIM chip socketed in my SE Reloaded board!

Well, that solves the mystery. Only thing I'd say is when I asked for a photo, I was looking for confirmation of what was absolutely in the board. Providing a photo of what you thought was in the board was perhaps counter productive and a little misleading.

But... we all do things like that. In a way I'm glad because it makes much more sense. The complete lack of references to a failed SWIM cell in the documentation, or the idea that you'd put two different parts inside identically marked packages is... worse.

Great news though! You now have a SWIM, and possibly a second on the way. Think of all the extra files you can store on a single disk!

 

[Kai Robinson]

I remember i sent a Harris branded SWIM over, now...although i've never seen Harris branded parts in Apple machines, i do wonder if it was a remarked part...

 

[JTRetro]

@phipli

JTRetro said:
In this test, I was once again using a stock SE 800k board with 4Mb of RAM, O.S. 7.1 running off of an original 20Mb drive, and PC Exchange is loaded and running. Oh yes, forgot to mention that this is firmware version .7d-fastscc:

And a superdrive?

Yes! I had both a super-drive and an 800k drive hooked up. The 800k drive was inside the mac and hooked to the front port; the 1.44Mb drive was hooked to the back port and hanging out on my desk. Additionally, here is a shot of my floppy chip: