Software-only OVERCLOCK for LC475, LC575, Quadra 605

[phipli]

Shhh!

He didn't mean that folks. Just a late April fools joke.

Its also the wrong PSU - it is the older, lower power LC / LC II style PSU, an ASTEC in fact

My LC 475 is an official body snatcher - someone bought the logic board upgrade kit with the sticker for the front case. Means the case has an LC II era serial number and the groove on the front of the case.

Don't worry though, I'm only overloading the PSU with a 53MHz OC, 7200 rpm 9GB disk and an ethernet card.

 

[jasa1063]

I have a Color Classic Mystic (LC 575 logic board). When I try to use the Soft-475-Overclock extension I get a red X on the extension during startup. Getting it on System 7.1, 7.5.5 and 8.1. I am using the v0.52 package. The documentation indicates that this is due to it not being supported on that logic board. Anyone else having this issue or know what might be the cause of this?

 

[Nitram78]

I have a Color Classic Mystic (LC 575 logic board). When I try to use the Soft-475-Overclock extension I get a red X on the extension during startup. Getting it on System 7.1, 7.5.5 and 8.1. I am using the v0.52 package. The documentation indicates that this is due to it not being supported on that logic board. Anyone else having this issue or know what might be the cause of this?

I'm having exactly the same problem with my Mystic. For now, I tested Systems 7.5.5, 7.6.1 ('gusd' ressource patched from 21 to 10 for Gestal ID 99) and 8.1.

 

[Nitram78]

I'm having exactly the same problem with my Mystic. For now, I tested Systems 7.5.5, 7.6.1 ('gusd' ressource patched from 21 to 10 for Gestal ID 99) and 8.1.

@jasa1063 , have you done the VGA mod on your Mystic ? I didn't, and I suspect people who recently tried software overclocking already had the VGA mod done.
With the aforementioned modification to the System file, the Gestalt ID returned by my machine is ‘99’, which corresponds to the LC 580. The Soft475 extension doesn't accept this, quite logically.
However, it is possible to work around the issue using Wish-I-Were, thus forcing the Gestalt ID to 92 (=LC 575) and only use Phipli's Control Strip, which modifies the CPU speed as expected this time.

 

[JDW]

MYSTIC UPGRADE: Hacks/Mods Clarified​

Today, a viewer of my 475 Overclock video said he has an LC575 board in his Color Classic without the VGA mod and is using the ResEdit hack (see 2.1.3 here) to "change the machine ID." He also said he was running System 7.5.5 but was having issues with @phipli 's Control Strip . (NOTE: If you use System 7.1, you merely need the correct System Enabler, which I describe in my Mystic video here, and is true even if you have one of the two VGA mods installed — I use v1.1.) But to use the ResEdit hack on S7.5.5 means to modify the System File inside the S7.5.5 System Folder to change the "Boot Process" from 21 to 10, but leaving the Machine Gestalt ID at 99.

Motherboard inside CC​	Gestalt ID​	Must Use This Boot Process​
Color Classic	49​	18​
LC575 with 640x480 VGA resolution	92​	10​
LC575 (33MHz) with stock 512×384 resolution	99​	10​

However, the MicroMac LC575 FAQ says that Boot Process change alone only works if your LC575 board is a 33MHz version. And it says if you have the 40MHz LC575 board, you must change the Gestalt ID from 99 to 92.

In other words, the 2 required CHANGES for the 40MHz LC575 board when using the STOCK RESOLUTION would be:

1. Set Boot Process to 10
2. Set Gestalt ID to 92

(And obviously, if you use ResEdit to make both changes, you would NOT need MachID Wannabe to change the ID.)​

This is confusing because PowerCC.org's Mystic page doesn't mention ResEdit at all and instead mentions the need to mod the LC575 motherboard ("logic board mod"). People show that process on the 68kMLA here. Indeed, @Mr. Fahrenheit said he ONLY did the ResEdit hack but got a Bus Error, and he later had success doing the LC575 motherboard mod, and he later added that the motherboard mod worked for him WITHOUT the ResEdit hack.

I never had to do any of that ResEdit or 575 MB hacking because after installing the 575 board in my CC, I only booted into S7.1 and therefore only needed Enabler v1.1. I didn't try S7.5.5 until I did the 68.4V VGA mod. I more recently switched to the 84V 13" High Resolution mod which also gives me 640x480. What I wrote above is info I gleaned from the internet and is not something I have personal experience with. Nevertheless, I do hope it helps (sorry, quite belated) @jasa1063 and @Nitram78 and also the viewer of my YouTube video (who I asked to post his experience in this thread).

 

[JDW]

I'm posting back in this thread today not only to give @phipli praise once again for his incredible work on the 475 Overclock software solution , but I also want to update all of you 475 Overclock users about the impressive work forum member @frontein1 has done (and continues to do) in boosting acceleration for those who also own a Universal ROM SIMM from CayMac:

https://tinkerdifferent.com/threads/testers-needed-modified-rom-for-lc475-q605.4603/#post-39970

With that ROM SIMM, you can not only boot from ROM Disks or even mount them while booted from your primary hard drive, but the SIMM also kills the RAM checking at cold boot, freeing you to install a 128MB RAM SIMM and have no boot time wait period.

As was the case with Spicy O'Clock, so it is with 475 Overclock. To reach higher overclocks you should not only install 60ns VRAM, but also a 60ns or faster RAM SIMM too, especially because of the work @frontein1 has accomplished today. His work is still ongoing and under testing, but the benchmark results he posted today are so impressive, I'm overjoyed to share the good word.

Kudos to the geniuses who continue to make this hobby not only fun but truly innovative too!

 

[YMK]

This is great work, well done!

On my 475, Clockometer tops out at 37.84 MHz, even if I choose a speed in the 50s.

The 20, 25, 33 MHz presets report correctly.

This 475 has been resistor modded to 33MHz.

 

[phipli]

This 475 has been resistor modded to 33MHz.

Don't forget the R95 / R96 mod too - it is generally needed for reliable SCSI at higher speeds. Moving the 0R resistor selects between clocking the SCSI at the bus frequency, or F/2. Spec says that machines with a bus of 33MHz and more should have F/2.

If you want more speed, switch out the 88920 for a 88916DW80. With the right CPU they're generally good to up around 50MHz then.

 

[YMK]

Thanks. I moved the resistor to R95 and the results are the same. I'm using v0.5.1 of the extension.

At 38 MHz, I get about 9 FPS in Duke3D with 320x200 and high detail. Typing DNRATE shows FPS.

@JDW I'm also curious about getting an FPS display in Doom. Let us know if you figure it out.

 

[JDW]

@JDW I'm also curious about getting an FPS display in Doom. Let us know if you figure it out.

I did an exhaustive amount of research into that, asking many, many people. It was a dead end.

But since were on the topic of Doom, I am thinking maybe @MacOfAllTrades might know because of their amazing work on getting it to function on an SE/30 here:

https://tinkerdifferent.com/threads/released-macdoom-for-se-30.5154/

 

[YMK]

I did an exhaustive amount of research into that, asking many, many people. It was a dead end.

I don't think there's an FPS counter in the core source like in Duke3D.

It's most likely a feature of specific ports.

 

[phipli]

Thanks. I moved the resistor to R95 and the results are the same. I'm using v0.5.1 of the extension.

I recommend using the control strip instead. It has better timings, is compatible with 24bit addressing and is easier to use.

Moving the resistor doesn't get you extra speed, it stops the computer crashing when you do sustained SCSI workloads like copying large files. Some machines aren't stable even at 33MHz unless you move the resistor, although I've never had issues at 33MHz myself.

To get more speed, the thing that is blocking you currently based on your symptoms (the speed just not getting higher past a point), you need to swap in the 88916DW80.

@JDW I'm also curious about getting an FPS display in Doom. Let us know if you figure it out.

All I think I remember is that in whatever version it does work, I believe you have to not have the viewport at full screen otherwise it covers the FPS?

There has to be a counter somewhere because it is in some people's videos isn't it? Or do I have false memories? Am I a Nexus 6?

DOOM II showing an FPS on an LC 475 - note how it isn't full screen quite :

Edit - Interesting, this one shows it while at full screen :

So it must just be a specific version of DooM II... this is what they launched, so not much to go on (sizes are dependent on block size and so hard disk size). Date Modified might be the biggest clue.