First post, by AlessandroB
I have an IBM PC330 DX4 which (as the name implies) comes standard with the Intel 486DX4. It is equipped as IBM standard with an additional regulator to bring the 5v to 3.3v.
https://drive.google.com/drive/folders/1-KiNs … y3W?usp=sharing
Here you will find the photos of the panel with the configuration and the photo of the review of the bios, I made the following tests:
1) 486 DX2 66 Mhz: it is seen correctly
2) 486 DX4 100Mhz: it is seen correctly
3) 486 sx 25Mhz: it is seen as 486sx33 (also selecting the jumpers for the 486sx as indicated on the cover)
4) AMD 5x86 P75: the screen remains black with any jumper configuration
5) Cyrix 5x86 GP100: the computer starts but from bios it is seen as an unknown CPU running at 75Mhz
6) Intel POD83Mhz: the computer starts but immediately after checking the ram, when it checks for the presence of a boot floppy, the computer turns off by itself.
Could you comment on the various problems? Thanks