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uniserver

Q605/LC475 (onboard) ram upgrade.

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Ok, so i have some good news…

the the Logic Board still boots and runs with out the 4megs of ram soldered onboard.

so that is pretty cool.

 

Screen Shot 2013-12-28 at 7.36.17 AM.png[/attachment]

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Were the onboard chips 80ns and the chips on your SIMM 60ns? Would something like that explain the speed boost?

 

I found an auction for a 16MB 30-pin simm, read the part number off the Siemens chips on it, did a little googling, and found this auction for just the chips themselves ($2 each in lots of 25). I'd be happy to split the cost of one lot with you if you want to try! (It's a "best offer" auction, so maybe we can get the price down some.)

 

Only possible snag: the chips in that auction are 50ns, while the fastest RAM I've ever heard of in a 30 or 72-pin SIMM for Mac was 60ns. Any reason a 475/605 couldn't handle the faster 50ns RAM?

 

144MB would be so gross! :o)

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Were the onboard chips 80ns and the chips on your SIMM 60ns? Would something like that explain the speed boost?

 

i was thinking about that…

(and that might be some of whats going on)

My theory is more that the memory controller has to ASINC the memory bus in order to use that stupid 4megs of slow old ram.

With that 4mb's not on there… the memory controller switches to synchronous mode. with a full pipe to the 72 pin simm…

 

The 24 pin ram might be faster ram all the way around… not in just NS.

 

I think that 20pin ram is old… and was thrown on there to save money and to give the customer a value added feature of some onboard ram.

after all the LC475 and Q605 WERE value added machines…. not performance…

 

So yeah i am saying the memory controller directly allowing greater performance.

Not having to slow everything down as the same speed is the S**T 4megs onboard.

 

I have no wiggle room in my budget.. -- and i have no idea as if those ram chips will work.

-- i do see they are 20pin… and i'm sure that is good… but other then that i have no idea… and no $$ budget.

 

-- i am almost thinking populating that spot with any 20pin ram chip is just going to slow the system back down….

 

WITCH leads me to now be more interested in trash80's idea :)

viewtopic.php?f=29&t=22643

he's probably on to something … Yeah … for sure…!

 

because 256 megs of ram in a LC475/Q605 would be more sick…

 

using 2 matchings simms with all 24 pin chips…. :-)

 

i think we need to look up a data sheet on the memory controller…. we might have found out its greater capabilities

----silly apple purpously slowing down our computers on us!!!!!!!!!!!!!!!!

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That would be interesting. The Q605 definitely does at least up to 260 MB of RAM. I know that from experience. And the 4MB on board can probably be replaced with 64MB, so I imagine that machine could go to 256 + 64 = 320MB at a minimum, perhaps more.

 

The IIsi should go to 128MB. My understanding is that it's essentially a IIci with a microphone jack, so the memory pins should be there for 128MB.

this was from here: viewtopic.php?f=9&t=15958

 

I guess this is good info for both of my threads… anything to help the cause.

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I love the way you took my grandiose schemes for the IIsi and came up with your own plans, attacking it from the IC side of Bank A there and for the Q605/LC475 here. You don't need to credit me for the IIsi idea. Great work there, uni!

 

The info in the thread you linked to is much more applicable to the 605, not so much the LC475. The MicroQuadraFeetsMac™ has handy, removable ribs hidden within the deeper, flat-n-feeted case. I posted the riddles/info in the IIsi thread to help, definitely not brag, I didn't want to steal any volume from your thunderous achievements. I love collaborating on a hack from multiple fronts. My back-burnered hacks would likely never be realized otherwise . . .

. . . now you can work out the mapping for 320MB or 512MB of 72-pin SIMMs in the 605! }:)

 

Removing the ICs from Bank A is a great start, BTW. De-solder the thru-holes for the unimplemented ROM SIMM for routing your jumper wires. and take the hack underboard/subterranean/fairly stealth, as I'm doing an under the board IIsi PDS hack. Only you won't have to cut a hole in the bottom if you use flat 72 pin SIMM Sockets or just solder them directly to the PCB at a very low angle . . .

. . . its not like you'll ever really need to upgrade the RAM again! :lol:

 

I'm glad you started this project, it gave me a big kick in the butt on a lost hack. I'd posted it by mistake in 68k LC & Performa instead of Mac II, Quadra & Centris for folks interested in the 605 might take note of it. I guess it really belongs here in Hacks & Development. I found it only by searching for the IIsi info, it never made it onto the crib-sheet topic I made for my projects.

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When I send you my 605 board for a recap, you'll have to benchmark the stock with 132 vs the "value-subtracted" with 128. It'd be interesting to see actual data on the bump!

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I could do those benchmarks now.

 

LC475 and Q605 main boards are the exact same.

 

I don't think I have ever seen a 256 meg 72 pin simm.

(just saying)

 

has anyone else?

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I didn't realize you had both handy. I'd love to see the difference.

 

I haven't seen 256MB 72-pin SIMMS ever. Could you put bigger chips on a SIMM? The stock SIMM doublers are too tall for the pizza boxes.

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not sure buddy.

- on the ram simm chip swap idea.

 

I got a boat load o work to do so, any benches for now, gotta wait.

 

If I had to throw out a number, I would say, feels like 20% better w/o that 4 megs on there bringing it down.

the difference seemed more significant when booted up Max Rez, the only other thing, at max rez, you only have 256 colors.

that might be less desirable for some.

 

Seems to me 20 pin ram is more likely on the older 30pin simms…

and the 24pin chips are mostly on the newer 72pin simms.

 

So i think its entirely likely that, the 4mb on there is handy capping the performance.

* maybe by design *

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ok i just did a real quick test Video and CPU only

 

- 605 is w/o the 4megs of ram.

- 605-w-4mb is acutely the really nice LC475 i got from mcdermd

(both OC'd)

I ran the test then i pulled out the ram and hd, installed into the other machine.

 

ok so the 605 w/o 4meg ram (Video benchmark) is the same as the Quadra 950 (127)

 

the 605 /w 4megs is (105)

 

the CPU is a little different too. but not much.

 

w/o 4mb ram is (130)

/w 4mb is (128)

[attachment=1]Screen Shot 2013-12-29 at 8.18.22 PM.png[/attachment]

[attachment=0]Screen Shot 2013-12-29 at 8.18.32 PM.png[/attachment]

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I bet the speed of the on-board RAM is extremely slow, So of course when you expand it, its still running at the speed of the on-board RAM.

 

Kinda like mixing DDR400 with DDR266. it runs at 266.

 

Which is precisely why when you remove the RAM, or replace the RAM with faster RAM on-board, it speeds up tremendously.

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The memory controller on the 605 supports interleaving, but the 4mb of onboard ram is not interleaved because it is just 4mb in a single bank.

The RAM SIMM will nearly always span banks and therefore be interleaved. Interleaving can give up to 10-15% speed improvement depending on how it is being accessed.

The onboard video will always come from the onboard RAM (if there is any), so it will always use the "slower" RAM.

 

You can also see this on the Centris/Quadra 610 and 650's. If you get one with 4mb soldered, it'll be non-interleaved, and if you get one with 8mb soldered, that'll be interleaved and therefore faster.

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JFYI, with the 610 series, you can't interleave RAM SIMMs because of the way they arranged the banks. It has half the SIMM slots, and rather than just leaving off the top 2 SIMMs, they've split things up so every other bank will be empty, preventing any interleaving of the SIMM slots. 8mb soldered is still interleaved, but the SIMM slots are gimped.

 

I never thought much of the 650 and 800 machines until I started messing with the memory controller. Now, they're pretty much my favorite 040's. Solder on a ROM SIMM slot, put a modified ROM on there to disable the RAM check and enable the 128mb SIMMs, and just have fun with a ~300MB RAM disk.

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lol how do you enable 128meg simms for the q800?

also can you be so kind as to pm me with that bin

awesome man!

 

Trash80 - The 605's removable ribs hidden within the deeper, flat-n-feeted case. I posted the riddles/info in the IIsi thread to help, definitely not brag, I didn't want to steal any volume from your thunderous achievements. I love collaborating on a hack from multiple fronts. My back-burnered hacks would likely never be realized otherwise . . .

. . . now you can work out the mapping for 320MB or 512MB of 72-pin SIMMs in the 605! }:)

 

yeah that would be pretty bad-ass to epoxy a 72pin simm slot to the bottom of the PCB and run some wires :)

but not through the rom slot holes.

 

with 512 megs of ram in a q605,,,,,,,,,,,,,,,,,,,,, we will need to disable the ram test for sure!

-- so the rom slot will be needed for sure. ( and a special bin )

 

if someone were to accomplish this… it would be the Mac HAC of 2014 :)

 

does bbraun want to take this on is the question 8-) ?

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Trash80 - The 605's removable ribs hidden within the deeper, flat-n-feeted case . . .

. . . now you can work out the mapping for 320MB or 512MB of 72-pin SIMMs in the 605! }:)

yeah that would be pretty bad-ass to epoxy a 72pin simm slot to the bottom of the PCB and run some wires :)

Nope, you'd be soldering the SIMMs to an adapter PCB soldered/socketed directly to the MoBo, nestled between the remaining ribs of the intact bottom surfaced case.

 

but not through the rom slot holes . . .with 512 megs of ram in a q605,,,,,,,,,,,,,,,,,,,,, we will need to disable the ram test for sure!

-- so the rom slot will be needed for sure. ( and a special bin )

Who said anything about not using a ROM SIMM, just move that to the adapter to make room for most of the wires, it sits on part of the same address/data/control line bus as the RAM, with a few ROM specific signals added, IIRC. Voila! Holes to spare! [}:)]]'>

 

if someone were to accomplish this… it would be the Mac HAC of 2014 :)

does bbraun want to take this on is the question 8-) ?

I hope he decides to get involved in this as well, I'm working out the funneling issues for using inexpensive 72-pin SIMMs already, albeit v-e-r-y slowly! ::)

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How about soldering a SIMM socket where the on board chips were?

 

I suppose it would have to be surface mount, but it could be done, couldn't it?

 

It would be a bit messier looking, I suppose, but more easily removable (and perhaps even a bit more reliable, since the extra length of the wires going underneath could do bad things to the signals running through).

 

c

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ok well for now we are going for 16 meg's of ram… MinerAI is sending me his 605 and some ram chips, I'll give it a try and see what happens…

after this.. I am going to try this with the IIsi as well, 16m in a IIsi will be kinda cool! :)

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What about the Q630/LC580? It has 4MB soldered on too, and is frankly a more full-featured platform (IDE, CommSlot, Video in/out) than the 605 or 575 boards. Has anybody tried a 128MB SIMM in there? Any reason to believe it would work any differently?

I'll have to snag my dad's 63x from his office at work and get it to Uni for recapping/experimenting. 8-)

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Funny you should mention the 630, I've been working from that DevNote this afternoon.

 

Curiously, it says the Q630 family came with either 4MB or 8MB on the MoBo and support for a double banked 32MB SIMM. However the Max Memory configs are listed and graphed/mapped as having a 36MB ceiling. I don't know where a 128MB SIMM might fit into that scheme, but the DevNote specifically states the 630's incompatibility with 64MB SIMMs.

 

I'm not sure where the TWO SIMM Slotted DOS Compatibles fit into that scheme?

_____Did they have DRAM soldered to the MoBo?

_____Did they eschew onboard RAM in order to address a pair of double banked SIMMs as four banks of RAM?

 

Curiouser and curiouser . . . :?:

 

 

edit: ISTR more memory being used in the 630, be that as it may:

 

I missed part of one page, but . . .

 

[attachment=3]Q630mem_A.jpg[/attachment]

 

[attachment=2]Q630mem_B.jpg[/attachment]

 

[attachment=1]Q630mem_C.jpg[/attachment]

 

[attachment=0]Q630mem_D.jpg[/attachment]

 

. . . zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz |)

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Technical information for the

Macintosh LC 630 DOS-compatible computer

General specifications

Memory

_8 MB dynamic random-access memory (DRAM) on board

_2 72-pin DRAM Single Inline Memory Module (SIMM) sockets for

_expansion RAM to 52 MB (80 ns)

_1 MB read-only memory (ROM)

_1 MB video memory

Curiouser and curiouser . . . :?:

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