I had a crack at the cyrix chip but didnt have much luck. Ill let you know how it goes in the um8810.

I think for now this system is finished!

The only thing that is on my nerves is that the Turbo Switch cable from the case is 3 pin but the motherboard connector is 2 pin so Im unable to get it working - Plugging in just two of the pins takes my PC down to 4mhz which cant be right surely 😀

Thanks for all your help.

Specs are as follows:

TSENG LABS ET4000/W32I VESA 32-BIT 2 MB DRAM
Intel 486DX4-100 Overdrive CPU
KUO SHENG VLB/ISA Motherboard (ASAKI Chipset)
64 MB Fast Page Ram
Unknown VLB Model IO Controller - UMC Chipset
CT1600 Sound Blaster Pro 2
CT1740 Sound Blaster 16 (MT32/SC55 interface)
Maxtor 1.01 GB Hard disk
Seagate Medalist 10GB Hard disk (jumpered to 2.1)
Mitsumi Quad Speed CDROM - FX400E
Generic 3.11 Disk Drive
Generic Serial Mouse
Honeywell Litetouch Keyboard
Microsoft Sidewinder Joystick
Pro Tech 486 Case
Hansol 920P 19inch CRT Monitor
Roland SC-55
Roland MT-32
MS-DOS 6.22

The turbo cable plug should be easy to mod. Just use a clipper to separate them into two individual ones 😀

Turbo does a lot of things on many boards, disabling cache, introducing wait states. I believe it's meant to be compatible with 4.77MHz type applications.

Very nice build I must say 😀

Where is the best place to source 1024k cache for a 486 board and what part numbers do I need?

feipoa wrote:

Anonymous Coward wrote:

It appears that your 5x86 is extra special, because it seems to have support for a 4X multiplier. 5x86-120 normally only has 2X/3X multipliers. If I am correct, you will be unable to run it in 2x60 mode as it has no 2X multiplier.

2X can be set in software on the 4X models. But what makes you think it is 4X-enabled? I thought the Cyrix 5x86-120/4x chips had "4x" printed on the ceramic top?

rgart, are you able to determine what multiplier your 120 is capable of? If not, perhaps when you find a more suitable motherboard...

How is this done?