Search results

Well, I think all the 500MHz issues have nothing to do with the processor or the bus. I think there's a hardware problem. This problem has gotten worse and worse, and now it's gotten to the point where the iMac boots up but no longer has an L2 cache, and nothing has changed since the last tests...

A question, how did you adjust the bus to 83MHz?

Mine's rectangular too, and at 466MHz like yours. I thought the problem was solved with the 7410s, but I don't know anymore. The strange thing is that I got it to run at 500MHz with a 2V Vcore, and now it's not stable. I can't even boot it.

Luck is not on my side. Adjusted to 1.83V:

Update: The stability issue seems to be due to excessive processor speed and likely temperature. The first boot seemed to go well, but as it heated up, it gave problems and wouldn't work. I lowered the bus to 66MHz and adjusted it to 500MHz. Upon boot, the chime sounded, but it wouldn't boot or...

The Lombard EEPROM have some value at position 20, the other nothing.

Hi, I did another quick test. Maybe the speed isn't set as a multiplier but as a fixed value, but in my case it's being complicated by the bus overclock to 83MHz. It doesn't like something. Up until now, it occasionally wouldn't boot on the first try, but on the second or third try, it always...

Looking at all my photos, I get the feeling that the EEPROM content is conditioned by the processor speed. Below 400MHz, everything works fine; we've always maintained the expected ratio, but at 400MHz or higher, the ratio drops. No matter what EEPROM is used, it always drops when reaching...

Hi @herd I've tried changing that value, but upon startup it tells me there's no L2 cache. I've attached the .bin file in case I made the change incorrectly. I've also attached the EEPROM dumps from the Lombard 400MHz with 1MB cache, which I believe has a 2.5:1 ratio as commented in previous...

Hello. Today I found some time and continued modifying the processor in my iMac G3. First, I swapped the 256kb cache chips for two 512kb ones taken from the same DA 466MHz daughterboard, clocked at 250MHz (it has the -25 at the end of the reference). Thanks @herd for your tips on working with...

Hi, I need to order from Digikey some items, but I can't find the 160-pin mezzenine connector opposite the one on the iMac. Does anyone know if it's available? What reference number would it have?

I have already received the adapter for the TL866, I just need time! In the post about overclocking the bus of this iMac I mentioned that it seems that the Cache ratio changes when changing the bus speed, according to Gauge Pro...

Thanks @Daniël, I've searched and it must be the one you mentioned. I'll try it! https://www.mouser.es/ProductDetail/STMicroelectronics/M24C02-WDW6TP?qs=Du8MRN8yFR6ucuUktOfCYg%3D%3D

Thanks for all this information. Unfortunately, it's beyond my knowledge; no matter how much I read and reread it, I don't know where to start. I would need someone's help modifying the EEPROM dump. Seeing the changes in firmware versions, if the Lombard EEPROM worked in an iMac G3 tray, would...

Do you have at least a 500MHz processor and 512MB of RAM? I think those are the minimum requirements. I was able to install it on a Pismo upgraded to a 500MHz G4, and it worked after updating to the latest firmware.

So, the XLR8 SPD EEPROM alone isn't enough to enable the cache? Is the MAChSpeed Control panel necessary? You mentioned that @dosdude1 used the SPD EEPROM from a Lombard and it worked, but at a 5:2 ratio. I have a 300MHz Wallstreet CPU that has a 2:1 cache ratio and uses 1MB. Could it be...

Hi @Daniël. As you know, I'm playing with an iMac G3 tray CPU, which I upgraded to a G4. If I were to consider swapping the original cache for the one that came with the 7400@466MHz DA, wouldn't it be enough to swap the G4 DA EEPROM with the one from the iMac G3? I also have the EEPROM from a...

Thanks for the explanations :)

Hi, the 300MHz Wallstreet processor arrived yesterday. I installed it in the iMac G3 tray, but it didn't work, as we expected. I can't verify the processor either because I don't have a Wallstreet processor, but it's probably due to firmware incompatibility. The iMac G3 tray doesn't seem to...

Hi!! You might be surprised that I changed the 66MHz XPC106 to a 100MHz one if I told you it worked. Well, it did, but the OS would occasionally pause, especially when copying files. So I suspected it wasn't very stable. I had a faulty B&W G3 motherboard at home, and I decided to replace it...