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I'd like some input on a 6300 CD modification possibilities

Ncc74656

Well-known member
I just bought one, got it because my first computer was a 630 and this is the same form factor but a smidge better

What are my options for a better video card for 3D gaming?

What are my options for overclocking the processor? It is currently 100 MHz

I have a lc2 networking card in the PDS. It does not seem to work. My thought is to buy is a cam slot networking card and save the PDS slot for something else.

What can I put into the PDS slot to make the system better?

Is there a mod to increase maximum RAM?
 

Franklinstein

Well-known member
There aren't a ton of upgrade options for the original logic board. There were never any processor upgrades available because there's no way to install one. The LC PDS isn't "real" on these (nor is it on any post-'030 Mac) and so it can't override the host processor. There were some fairly rare video cards available for the LC PDS that may improve graphics slightly but not enough to be worth the money. Otherwise the only other common option would be the network card; the Apple IIe card won't work in these.

RAM is in 72-pin SIMMs and there are two slots available for a max of 64MB. There's no way to increase it beyond this.

CPU overclocking isn't really a thing on these. It's possible to move some resistors around to change the multiplier but this isn't well documented and I don't think it usually works, especially since the only higher option to clock to is 120MHz which is typically a bit much for these.

The Comm Slot here is the early type, so if you look for an Ethernet card for it, make sure it's Comm Slot, not Comm Slot II, because they're not compatible. The only cards that will work in either type of slot are the modems and there's not much point in installing a 14.4 or 28.8 modem in this day and age, especially since it disables one of your two serial ports if you do so.

Arguably the best upgrade for these is a PCI logic board swap and this requires a wiring harness mod to get it to work. Essentially you'd cut a specific ground wire at the harness and install a 3.3v regulator in its place. It's not super difficult but usually requires some soldering.
 

Ncc74656

Well-known member
I'm considering buying a 6360 I found online, may be replacing this one.

So my original computer was 630 CD. That had a "real" PDS slot? Just kind of curious what I could have upgraded that thing to when I was a kid. I begged my mom to buy Mac OS 8.6, only to find it wouldn't run on 68k... lol

What kind of logic board mod would you be talking about? Swapping out to the 6360? I'm fine building power supplies, I fix amplifiers and working Automotive Electrical so that kind of stuff is no problem
 

Franklinstein

Well-known member
In a nutshell: the LC PDS was originally a 16-bit interface that was directly connected to the 68020 in the LC. It was later expanded to 32 bits in the LC III, LC 550, and other full 32-bit '030s, though very few cards ever used the full 32 bits; most stayed 16 bit for compatibility with the older models. They were still directly wired to the host CPU via the '030 bus, which is why accelerators and things worked: they could fully override the host CPU and take its place directly.
With the '040, Motorola changed the bus protocols, so there was no way for an '030 bus-based device to interface to the '040. Apple used a custom chip (PrimeTIme) to basically act as a bridge: the chip provided an emulated '030 bus and handled the necessary protocol translations and buffering for data to/from the '040 bus. Because of the bridge chip, the LC PDS no longer has a direct line to the CPU, so it can't take over the '040 bus or even access it natively and thus there's no way to use it for upgrades. This is true of any '040-based Mac with an LC PDS.

Short answer: no, the Q630 did not have a "true" PDS available. The only upgrade available (the PPC upgrade card) installed directly into the '040 socket. This is essentially what the 6200 and derivative machines is: a Q630 with a preinstalled PPC upgrade card.

The PCI logic board upgrade would use an Alchemy (54/64xx or 6360) or Gazelle (55/65xx) logic board in place of the original non-PCI logic board with the addition of the voltage regulator. Basically you don't do anything to the replacement logic board; you modify the computer's harness and then slide the board in and it'll work. I don't remember offhand exactly which wires are affected (it's on the forum here somewhere), but basically the harness in pre-PCI models supplies 5 power lines: +12v, +5v, and 3 grounds. You cut a specific one of the ground wires and in its place install a +3.3v regulator supplying voltage to the logic board. I usually pull the supply voltage for the VRM from the 5v line to simplify things.
 

Ncc74656

Well-known member
Got it, well I might by myself is 6360 out right and run that. Then I would sell the current ones I have. I'm going to completely rebuild the 6300 power supply tomorrow, I bought all new parts for it. What do you think a 6300 should sell for?
 

alectrona2988

Well-known member
I wouldn't consider these particularly valuable, but at best someone could buy it off of you for $100 on eBay or something.
 

Cory5412

Daring Pioneer of the Future
Staff member
Unfortunately there's almost nothing you can really do as far as "mods" to a 6300.

You can replace the HDD and CDROM drives if they need it (SD cards may work better).

It's a competent machine, but it's not particularly flexible. They're really great first Macs, reintroduction machines, something you give to a friend who has a kid they want edutainment for, or just a daily driver/beater type of machine.

something else.

Unfortunately there's not an awful lot for LC PDS that's both better than ethernet and runs on one of these. It's not nothing, but really, LCPDS Ethernet as you already have is likely your best bet.

Mirroring what has already been said, if you want Hot Performance or moddability, there's machines that will likely scratch that itch better.

The 6300/100 should perform Fine(TM) -it will be noticeably faster than the 630 at literally everything and if you max its RAM it should also competently boot into mac os 9.1 for things like fetching files, although you may find 9.1 is a bit heavy for daily use (it certainly is on my 6200, which I use with 7.6.1.)

EDIT/Add:

So my original computer was 630 CD. That had a "real" PDS slot? Just kind of curious what I could have upgraded that thing to when I was a kid. I begged my mom to buy Mac OS 8.6, only to find it wouldn't run on 68k... lol

There are upgrades specified as being "for" LC-PDS machines but they don't really use the PDS slot -- they plop directly into the 68040's CPU slot Some more/starter info: https://lowendmac.com/2016/powerpc-601-cpu-upgrades-for-68040-macs-with-lc-pds/

Franklinstein mentioned this but these upgrades are sort of the long way around to just building the 5200/6200. Franklinstein didn't say this directly but as a caution on the 5200/6200 and 5300/6300 (plus the PowerBook 5300, 1400, 2300) - many sources still incorrectly cite some old Low End Mac articles that incorrectly describe the architecture of the machine.

They are slow, but not really as slow as described, and there's some software-based help available to make them feel more sprightly and outbench some of their first-gen PPC siblings.

That said, the second half of my 5200+ software recommendation is Speed Doubler 8 and using Mac OS 7.6.1 or probably 8.1. Those get you speed and reliability benefits over 7.5 on their own and then Speed Doubler replaces the 68k emulation components built into Mac OS with a significantly faster one. (Every system 7 on PPC mac can get that benefit but by the time you get to either 8.5 or 9.x the built-in 68k emulator outperforms the SD8 one.)
 
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