Pretty awesome project I’d like to make one of these on one of those clear colored macs one day. That would be pretty awesome.

Chkcpu wrote on 2023-06-29, 19:50:

Hi lunarApple, […]
Show full quote

Hi lunarApple,

A multiplier of 6.5x or higher does not exist on any Socket 7 CPU, but all K6-2CXT models, like your K6-2/450, and all K6-III, K6-2+, and K6-III+ CPUs do support the 6.0x multiplier.
Just set the multiplier at 2.0x and you will get 6.0x. This works because the 2.0x setting on these CPUs is internally remapped to 6.0x. 😉

However, the stock BIOS for the OPC620 card doesn’t support the 6.0x multiplier, so you will need to install my patch J.1 version for that.
Sorry that the old direct link to this OPC620J1 BIOS is broken. I had to move my website to a new domain. The new link to this patched BIOS is: http://www.steunebrink.info/bios/OPC620J1.zip

Cheers, Jan

Nice! Thank You. I shall give it a go then.

dr.zeissler wrote on 2021-09-08, 15:52:

Thx, I can mount the drive, I got the drive-letter but if I want to access it I always get an error and the drive is not accessed. I have to try again and make a screenshot.

BTW I know it's been 2 years so you probably don't care any-more but I found a solution for the problem. I was having the same error on my 6400 mobo + 600i cd-rom:

Here is what I posted on another forum:

"I found an app "SCSI Probe 5.2" When the CD-ROM does not work, I have to go back on the mac side and manually mount the CD through that app, then it will start to be accessible on the x86 side.

Also I found these:

http://web.archive.org/web/20180822093828/htt … 0Micro/misc.zip
https://web.archive.org/web/20130416073257if_ … ePC%20Drive%20D
https://web.archive.org/web/20130416021726if_ … y%20Install.dmg

I think these drive images include a pre-installed Windows 98, although after I was able to get the CD working I just installed W98SE from the normal OEM CD and included with OrangePC 3.4 win98 bootdisk image.
"

Chkcpu wrote on 2023-06-29, 19:50:

Hi lunarApple, […]
Show full quote

Hi lunarApple,

A multiplier of 6.5x or higher does not exist on any Socket 7 CPU, but all K6-2CXT models, like your K6-2/450, and all K6-III, K6-2+, and K6-III+ CPUs do support the 6.0x multiplier.
Just set the multiplier at 2.0x and you will get 6.0x. This works because the 2.0x setting on these CPUs is internally remapped to 6.0x. 😉

However, the stock BIOS for the OPC620 card doesn’t support the 6.0x multiplier, so you will need to install my patch J.1 version for that.
Sorry that the old direct link to this OPC620J1 BIOS is broken. I had to move my website to a new domain. The new link to this patched BIOS is: http://www.steunebrink.info/bios/OPC620J1.zip

Cheers, Jan

Ok so I tried the modified bios just now and at a 2x multiplier I am getting 256mhz on a K6-2/450AFX

Check it with software, don’t trust the bios reading. Sometimes the bios doesn’t have the correct speed detection. CHKCPU might be able to adjust that?

If you pull bf0 and bf1 correctly, the CPU WILL be at 6x this is done in the cpu. So if you have 66mhz fsb and pull bf pins correctly, you will have 400 mhz guaranteed. 75mhz fsb will be 450 mhz and 83 fsb will be 500mhz the only exception would be on + cpus where the multi can be overridden in software after boot

CHKCPU, SetMul and similar utilities displays the correct CPU clock frequency. Whatever is displayed on the POST screen isn't relevant if everything is fine afterwards.

lunarApple wrote on 2023-06-29, 23:42:

Ok so I tried the modified bios just now and at a 2x multiplier I am getting 256mhz on a K6-2/450AFX

Other OPC620 users reported the same erroneous 256MHz indication when using the 2.0x = 6.0x multiplier setting on the stock BIOS with a K6-2 or K6-III. However the patched BIOS indicates the correct CPU speed here, so something didn’t go well when installing the patched BIOS and I believe you are still running the stock one. 😉

Copying the patched BIOS at the correct position into the BIOS file of the OrangePCi application is a bit tricky. Earlier in this thread user Nathan_A wrote a nice tutorial on how he did that.

Did you use a similar technique or do you use another method when updating the BIOS. Just curious. 😀

Cheers, Jan

I have the opportunity to have a Orange PC Card 420 (is a 486 class one) pci interface. The fact is that i only have a G4 Powermac Quicksilver tha t have a 64bit pci (32bit compatible) and runa natively osx and os9.2.2 but i absolutely not inow if this orange 420 can work on my mac… someone can tell me something? Tnks

Re: OrangePC 530 pinout, bios update, vram upgrade

Hey, huge favor, any chance you could map the pinout?

I will make a new attempt to get my 620 working in my G3 B&W with G4/500 Upgrade. Too bad jan never figured out how to make use of pci-cards because in my G3 beside that R128PCI I have 2xVoodooII via SLI.

Going back to the 620 card. What CPU should I use to get a stable working machine. I have read some issues about hangs during boot up. To me it's not about getting the fastest cpu running, it's about getting a good reliable cpu running that has a good performace but does not generate too much heat. Should I go for a K6 oder should I go for a P233mmx. Because the space is really limited on the hight, I need a very plain CPU heatsink and cooler to get it fitted into the case.

EDIT1:
Too bad the orange-metric does not show the power-consumption on the later K6-2/3 (+) models. Having only this metric shown below going for the p233mmx would be the obvious choice for me. The G3 B&W has a big fan right before the CPU and the PCI Slots, so going for a passive-heatsink should be ok I think.

EDIT2:
https://www.computerbase.de/artikel/prozessor … 86-retro.77695/
According to this article, the later models are more efficient. Too bad they do not have tdp values on the later (+) Models. I think I will go for something about 15-17 Watt TDP.

EDIT3:
These are the K6-CPU's I have. I think I will go for the K3-III 400 (4x100Mhz). I forgot there is no 100 Mhz Setting. ! I will try the recommended setting for that CPU.
This should be OK in terms of thermal conditions (18 Watt TDP) and this could work on stock bios because I do not use 6x (which means setting 2x). The manual lists the setting for that K6-III/400 so I will try it out.

Jan wrote: "The latest, and probably final, BIOS upgrade from OrangePC for the model 620 Windows compatibility card is contained in the version 3.4.x application. This BIOS does not support the (mobile) K6-2+/III+ CPUs. Also the original K6-2CXT/K6-III is not fully supported because this BIOS doesn't support the 6.0 multiplier."

EDIT4:
The recommended setting for the K6/3 400 is indeed 66FSB and Multi 2x. So Jan might seem right that it will not work without the patched Bios because he stated that 2x which means 6x interpreted by the CPU will not work with the stock bios. I am thinking about it. The K6/3 will be the best CPU I have for that card.

Dip-Switch Settings seem to be ignored by the K6-3. So I always end up in 256Mhz Mode. Heatsink get's REALLY hot after a view minutes. That is not the way to go. I had to take out one of the Voodoo2 in order to make the 620pc fit in the slots. I am thinking about the project and hopefully make a decision on the type of CPU I will put in that thing.

I also have to be careful if I put a fan on that thing. There is a 3pin header but it seems it supports either 5v or 12v fans. Putting a 3pin Fan on it grills the fan 🙁 I already encountered that.

I think one of the better chips to try in these cards is probably a cyrix 366 2.9v

Past that, prob gonna need a interposer.

I ended up with a K6-2/300 which ran fine. I also put a fan on it.