Recent content by frontein1

What you said @trag :) I also noticed all of my SIMMs are EDO not FPM. But I am not sure if that makes much of a difference with power drain. I'm out of town at the moment. But when I get back my next step will be to look up the chips individually to see how they compare.

I'm pretty close to getting 512MB to register in the Q650, at least I hope. I do think it may have to do with the power/voltage drain by the big SIMMs. When I poke the 50F0E000 register and set the OneBufferedBus bit, the Q650 posts and does a full boot with 4x 128MB SIMMs. But by setting this...

@JDW yes lots of really good info regarding overclocking the MEMCjr and djMEMC. That is next on my list to continue that. Otherwise been out of pocket for a while working on some other hobbies. Returning to my newly arrived Q650, I can get it to register 328MB of RAM so far (8 onboard + 128...

Do you know the speed of your RAM SIMM? If the onboard RAM is disabled during sizing, I think the MEMC still defaults to 80ns if I remember correctly. So you'd need to poke the right register to step down to 60ns. I know this works OK on the LC475, not quite sure on the LC575. But that machine...

Actually the "stock" benchmark on the left is all the default settings - 33MHz and 80ns RAM latency. So no changes to the IC registers. The "mod" benchmark on the left is 40MHz and 60ns RAM latency. So this might be what you were looking for :) @zigzagjoe pointed out to me on the 68kmla that...

OK I ran an initial benchmark with extensions disabled on my LC475/Q605 with v092 of the ROM. Remember this version has the onboard chips disabled. I borrowed that hack from @Mustermann, and I also borrowed his LC475SetCPUClock program. But I made one change to the Config register bits for...

Agreed this is pretty darn cool!

Here is the "proof" that the v092 ROM for the Q605/LC475 (above) bypasses counting RAM bank 0 (slow onboard chips). Over the next couple days I am going to work on the Config register to see if I can get the MEMCjr to address the RAM at 60ns with the onboard chips disabled. (If you read the...

Close. There are distinct steps to test the RAM and size the RAM. All versions of this ROM bypass testing RAM (onboard & SIMM) to facilitate a faster boot. But specifically for v092, this version purposely does not accumulate the size of the onboard RAM for usage. So essentially the onboard...

Taking an idea from user @Mustermann on the 68kmla, I have a new version for the LC475/Q605 which bypasses counting the onboard memory. See link below. https://68kmla.org/bb/index.php?threads/lc475-disable-onboard-ram.49016/ At offset A027C I basically just jump to offset 61030 in the ROM and...

Attached is ROM checksum 42 0D BF F3. Any of the machines listed below should be shoe-in candidates for testing: Quadra 700 Quadra 900 I currently do not have a Q700, but one is in the mail. So I did my testing of this modified ROM and disk driver on a IIsi. Stay tuned for more ROMs with...

Just to point out, you can easily change the size of the disk image on these ROMs if you do not have an 8MB SIMM. Just change the following offset to the disk size you will be using, and append a different disk image. I will write up an instruction manual soon :) offset 61010 = ROM/RAM disk...

Attached is ROM checksum F1 A6 F3 43. This ROM has a 7MB disk appended, so you will need an 8MB SIMM. Any of the machines listed below should be shoe-in candidates for testing: Quadra 610 Centris 610 Stay tuned for more ROMs with these same hacks. If you have any special requests, please let...

@Willj these low profile 8MB SIMMs are just awesome in my humble opinion. They allow me to close the cover on my Quadra 605. My younger kid says the ROM LEDs look like lasers :)

@JDW had a really good idea regarding this thread. This was to be more verbose in the machine models that could be used for each ROM. So on the attached file, this is ROM checksum FF 74 39 EE. This ROM has a 7MB disk appended, so you will need an 8MB SIMM. Any of the machines listed below...