Mystic Overclock - A Spicy O'clock Adventure

[JDW]

Do you have AppleTalk turned off in Chooser ?

I disabled AppleTalk from even loading, along with everything marked "open transport." In fact, I even removed the Chooser in hopes of getting it to work. Again, sometimes OS8.1 boots but mostly it freezes during the boot sequence. I can boot 7.6.1 more often than 8.1, but it's still pretty bad. 7.5.5 and 7.1 are bulletproof at 49MHz and work fine every time I boot.

 

[Fizzbinn]

Following this thread makes this come to mind:

 

[MacKilRoy]

I disabled AppleTalk from even loading, along with everything marked "open transport." In fact, I even removed the Chooser in hopes of getting it to work. Again, sometimes OS8.1 boots but mostly it freezes during the boot sequence. I can boot 7.6.1 more often than 8.1, but it's still pretty bad. 7.5.5 and 7.1 are bulletproof at 49MHz and work fine every time I boot.

The AppleTalk setting in the chooser is independent of the chooser and AppleTalk/OT extensions being loaded.

It’s a setting saved in the PRAM and if you don’t have a battery installed, it resets to “active” even if you don’t have the AppleTalk, AppleShare, or chooser active. It gets reset with each power up.

With AppleTalk active, the system checks the serial ports on boot, and your overclock likely makes the serial ports not work, so it crashes on boot.

 

[JDW]

It's really like Scotty in That Which Survives (photo below), where the Enterprise blows past Warp 13. It's a speed unlike anything achieved before! That's what it's like to hit 51.1MHz on a Mystic with @Kay K.M.Mods Spicy O'Clock!

But again, I get pixel dust (pixie dust? ) as the arrow pointer moves at that clock speed, all the way down to about 49.29MHz. I tested the Mystic extensively at 49.16MHz yesterday (with the heater on to keep the room about 20°C), and there was no pixel dust at that clock speed, but OS 8.1 and 7.6.1 are still a thorn in my flesh at any speed above 44.44MHz.

I look forward to hearing from you about your testing with those OS's, @Drake !

 

[JDW]

The AppleTalk setting in the chooser is independent of the chooser and AppleTalk/OT extensions being loaded.

It’s a setting saved in the PRAM and if you don’t have a battery installed, it resets to “active” even if you don’t have the AppleTalk, AppleShare, or chooser active. It gets reset with each power up.

With AppleTalk active, the system checks the serial ports on boot, and your overclock likely makes the serial ports not work, so it crashes on boot.

Very interesting. Thank you for that info.

Although Systems 7.1 and 7.5.5 boot fine (unlike 7.6.1 & 8.1) at overclock speeds higher than 44.44MHz, when I try to open the AppleTalk control panel in System 7.1 at 49MHz and then click "No" when it asks me to activate it, the machine freezes. So long as I don't fiddle with AppleTalk in 7.1 or 7.5.5, those OS's work boot fine and work fine.

Currently, Drake and Kay are my only two resources to help recreating my findings. I think it's important to try recreating the same problems to see if there is consistency. My guess is they too will have the same problems, but I would like them to confirm that. I can then present that detail in my overclocking video.

Basically, I want to show Spicy O'Clock as it pertains to the Color Classic Mystic, show the installation, the frequency counter I built to test it, then show benchmarks and explain the caveats. I've been discussing mostly the caveats in this thread. No doubt some of this information will pertain to the other Macs Spicy is compatible with. As of today, as per Kay, that compatibility includes the following:

• LC475
• LC575(Mystic)
• Performa 588
• LC630
• Quadra/Centris 650
• Pioneer MPX-LX100 (Mac Clone)
• Quadra 800
• Quadra 840AV
• In addition to the above models, Spicy O'Clock! can be used on any vintage Mac model which uses the XC88916DW or MC88916DW or 343s1108 Clock Driver chips.

 

[MacKilRoy]

I disabled AppleTalk from even loading, along with everything marked "open transport." In fact, I even removed the Chooser in hopes of getting it to work. Again, sometimes OS8.1 boots but mostly it freezes during the boot sequence. I can boot 7.6.1 more often than 8.1, but it's still pretty bad. 7.5.5 and 7.1 are bulletproof at 49MHz and work fine every time I boot.

If you can boot into System 7.1 and enter the chooser and set AppleTalk to “inactive” it will stay that way until you power off.

Then you could boot into a higher Mac OS that is freezing on boot and see if it progresses further.

 

[JDW]

If you can boot into System 7.1 and enter the chooser and set AppleTalk to “inactive” it will stay that way until you power off.

Then you could boot into a higher Mac OS that is freezing on boot and see if it progresses further.

I spent my lunch break testing that, in fact. I first booted into 7.1 at 44.44MHz, verified AppleTalk was off (in the Chooser), then rebooted into 7.6.1, which was fine. I confirmed AppleTalk was off there too, then shutdown, pulled the motherboard, flipped the switch on Spicy O'Click to the Max setting (49.16MHz), then rebooted. 7.6.1 froze during the boot sequence. Thankfully, I was able to reboot with Shift held down which got me to the Desktop. That doesn't always work though. I verified AppleTalk was off in 7.6.1, then used System Picker to reboot into OS 8.1. That booted (not surprising, as it randomly boots and doesn't boot). I verified it was OFF in 8.1 too. But as soon as I start changing Control Panels or Extensions (even if but to enable and then disable only one), I often get a freeze during the boot sequence, at the very beginning where the bar graph just starts to show. It freezes before any CP icons appear at the bottom.

So AppleTalk being ON or OFF doesn't seem to matter. At 44.44MHz, all 3 OS's work fine. At 49.16MHz, only 7.1 and 7.5.5 reliably boot, with 7.6.1 & 8.1 being hit and miss. And again, sometimes even rebooting with Shift held down won't stop the freeze. I then either need to boot from a floppy or pull the motherboard to kick down the clock speed.

Still looking forward to your testing of these OS's, @Drake !

 

[Kay K.M.Mods]

@JDW @Drake , thank you for the details. I'm testing 64MB and 128MB of mystic's memory at 42MHz respectively, but I think I'll have to reconfigure mystic's test model this weekend. Now I have to draw a Performa 588 overclocking schematic for Spicy O’Clock !, so I have to do that first.

 

[Drake]

I spent my lunch break testing that, in fact. I first booted into 7.1 at 44.44MHz, verified AppleTalk was off (in the Chooser), then rebooted into 7.6.1, which was fine. I confirmed AppleTalk was off there too, then shutdown, pulled the motherboard, flipped the switch on Spicy O'Click to the Max setting (49.16MHz), then rebooted. 7.6.1 froze during the boot sequence. Thankfully, I was able to reboot with Shift held down which got me to the Desktop. That doesn't always work though. I verified AppleTalk was off in 7.6.1, then used System Picker to reboot into OS 8.1. That booted (not surprising, as it randomly boots and doesn't boot). I verified it was OFF in 8.1 too. But as soon as I start changing Control Panels or Extensions (even if but to enable and then disable only one), I often get a freeze during the boot sequence, at the very beginning where the bar graph just starts to show. It freezes before any CP icons appear at the bottom.

So AppleTalk being ON or OFF doesn't seem to matter. At 44.44MHz, all 3 OS's work fine. At 49.16MHz, only 7.1 and 7.5.5 reliably boot, with 7.6.1 & 8.1 being hit and miss. And again, sometimes even rebooting with Shift held down won't stop the freeze. I then either need to boot from a floppy or pull the motherboard to kick down the clock speed.

Still looking forward to your testing of these OS's, @Drake !

I'm trying to accomplish these tests today if my 6 month old permits it
- 5am Canada, Igloo time

 

[Drake]

@JDW
I was able to hop in and quickly do a test build of system 8.1 today during my daughters nap!
I removed anything to do with networking just to be safe.

On the resistor mod rev. A logic board, Stock analog board:
48.88 MHz - Very stable here from 24.317 hz -> 24.387 hz. Any further and it's blue scrambles.
No bus errors to speak of so far which is promising BUT, can we truly be happy with ONLY 48.88 mhz?
System profiler reports it as 49 Mhz which is nice for my ego but you all know the truth.

Take THAT 840av!

 

[JDW]

@Drake , thank you for testing.

Your mention of the "resistor mod" means you have the stock 512x384 resolution with your LC575 Mystic motherboard. For those of you following this discussion, the resistor mod is used to make System 7.5.5 to 8.1 work without any software hacks. (See "Logic Board Mod" here.)

For the record, I can sometimes boot 7.6.1 & 8.1 without fiddling with Control Panels and Extensions, but it will freeze at boot even eventually. Drake, if you did multiple reboots and did not have a single freeze at boot, then such implies that what I am seeing could be a VGA-related thing, in which case we need @Kay K.M.Mods to do the 7.6.1 & 8.1 boot testing, since he has at least one VGA Modded Mystic in his collection. (With the VGA Mod in place, you don't need to do the resistor mod to boot into System 7.5.5 and higher.) Again, the boot freezes I am seeing with 7.6.1 & 8.1 only happen at very high clock speeds beyond 45Mhz. At lower clock speeds, there are no boot freezes at all. And regardless of clock speed, 7.1 and 7.5.5 boot just fine.

When I had the stock 512x384 resolution, whenever I would overclock too high, I would get the vertically rolling blue screen of death. But after the VGA mod, that rolling blue screen has not appeared at all, and as such I was able to reach Spicy O'Clock's speed limit of 51.1MHz. I did not maintain that speed for long because I would get the pixel dust when moving he arrow pointer (a sign the machine will lockup at some point, and indicates the VRAM is too slow to keep up at that clock speed). If we had 50ns VRAM, it might be a cure, although it seems those chips do not exist.

Separately...

In my testing last night after work, I found the following to be true on my VGA modded Mystic:

• With 80ns stock VRAM, I get pixel dust following the Arrow pointer at 41.55MHz. I've not seen that pixel dust yet at 41MHz or below.
• My 33MHz rated LC040 (stock LC575 board CPU without FPU) can be overclocked to a max of 45.18MHz (Spicy O'Clock Middle setting, 1.1kΩ resistance), when using 60ns VRAM.
• Serial Ports working at 43.48 MHz, but they stop working at 43.7 MHz.

 

[endsjustify]

Out of curiosity are you seeing your comm slot disabled after overclocking? After installing my spicy I lost the ability to boot when my Ethernet card is installed in the lc comm slot at basically any speed setting. If I remove the card, boots right up. Was curious if this is common or if I may have zapped it while I was working on the board.

I’m just going to switch out to a pds ethernet card or maybe leverage my rascsi for Ethernet. But was curious if anyone else had seen that. Rev a board mystic with a full 68040 proc and 640x480 mod (analog board mod).

this thread has been great, thanks much guys!

 

[JDW]

Out of curiosity are you seeing your comm slot disabled after overclocking? After installing my spicy I lost the ability to boot when my Ethernet card is installed in the lc comm slot at basically any speed setting. If I remove the card, boots right up. Was curious if this is common or if I may have zapped it while I was working on the board.

I’m just going to switch out to a pds ethernet card or maybe leverage my rascsi for Ethernet. But was curious if anyone else had seen that. Rev a board mystic with a full 68040 proc and 640x480 mod (analog board mod).

this thread has been great, thanks much guys!

If someone ever ships me a COMM slot card for my LC575 Mystic motherboard, I will be sure to test that! I have no idea if the slot works or not because I don't have a single card to put there. Maybe Kay can test that. But if any of you absolutely hate your Apple IIe cards and are looking for a new home, I think Japan would be a nice place for one! I'd love to test that!

 

[endsjustify]

If someone ever ships me a COMM slot card for my LC575 Mystic motherboard, I will be sure to test that! I have no idea if the slot works or not because I don't have a single card to put there. Maybe Kay can test that. But if any of you absolutely hate your Apple IIe cards and are looking for a new home, I think Japan would be a nice place for one! I'd love to test that!

I could certainly lend you my Ethernet comm card to test with, if it’s of value to the community to do so. I’d like it back but it’s clearly serving no purpose at the immediate moment.

 

[JDW]

I could certainly lend you my Ethernet comm card to test with, if it’s of value to the community to do so. I’d like it back but it’s clearly serving no purpose at the immediate moment.

Two-way shipping would be costly because I am based in Japan and because USPS strong-armed Japan to increase prices by 20% in June 2021! Besides, if @Kay K.M.Mods can test an Ethernet card in one of his Mystic machines (at a high clock speed), that would be all that is needed.

 

[Drake]

@endsjustify I will test this on my end as well. If it prevents boot up at any rate we can assume the LC comm slot heavily relies on specific timing.

@endsjustify it turns out my two cards are actually too tall to clear the internal plastic that holds the scsi cables. So myself am limited to using PDS ethernet cards anyway

 

[Kay K.M.Mods]

Two-way shipping would be costly because I am based in Japan and because USPS strong-armed Japan to increase prices by 20% in June 2021! Besides, if @Kay K.M.Mods can test an Ethernet card in one of his Mystic machines (at a high clock speed), that would be all that is needed.

I haven't been able to check the details, but the LC475 has almost the same configuration, the LDS slot does not work at the same high clock as the serial chip. Probably because of the clock timing mismatch. The same is true for AppleTalk...
If I have time, check how far I can drop the clock to see if it works...

I'm flooded with ideas right now and thanks to you all... I've had a great experience

 

[nottomhanks]

I'm looking forward to putting mine in my Mystic soon.
I'm just getting the analog board redone.

Has anyone tested the Spicy with the Apple IIe card? I'd be curious how high it can go while still functioning normally.

Also, would like to use RaSCSI for HD and ethernet.

Would love to hear everyone's thoughts.

Craig

 

[JDW]

I'm looking forward to putting mine in my Mystic soon.
I'm just getting the analog board redone.

Has anyone tested the Spicy with the Apple IIe card? I'd be curious how high it can go while still functioning normally.

Also, would like to use RaSCSI for HD and ethernet.

Would love to hear everyone's thoughts.

Craig

Craig, perhaps @Kay K.M.Mods can comment, but since I do not have a IIe or RaSCSI, I really cannot answer your question.

 

[Drake]

Craig, perhaps @Kay K.M.Mods can comment, but since I do not have a IIe or RaSCSI, I really cannot answer your question.

@nottomhanks
48.8mhz and running fine, I guess the IIE card isn't dependent on the logic boards timings as the IIE card contains it's own clock, it really is another computer in itself. Glad running this through the PDS is good to go, many users who build a Mystic may already have or want IIE card for both having the slowest (IIE) and fastest (Spicy Mystic) machine AIO