Need Help on a Vortex Golden Gate 486slc/25

[Pior]

I was looking to upgrade my Vortex Golden Gate 486slc. I have two different cpu chips and was wondering which one of the two would be the best option and if I need any other special software or need to change anything else on the board.
The two chips I have is a CX486SLC2-50MP and a [FONT=&quot]TI486SXLC2[/FONT][FONT=&quot]-G50-PQ. [/FONT] Are they the same, if not what are the differences. I will take any help on this..

 

[trixster]

Hi pior,

I have done this upgrade on my GoldenGate 486SLC2.

the TI486SXLC-G50-PQ is the better chip as it has 8K L1 cache compared to 1K on the CX486SLC2. This makes a high difference to the boards overall performance even though both chips can clock-double to 50Mhz. These 386SX-class processors have 486 instruction sets but they are limited by a 16bit external memory bus, so the additional cache on the TI makes a huge difference for games which require memory-bandwidth, such as Doom.

you need to enable the clock-doubling and cache with software

I can’t remember where the correct software came from but it is attached to a post in a thread on this forum. this line in autoexec.bat activates the clock doubling to 50Mhz and the cache:

cache486 2+

/edit software is here, bottom of post #7

https://www.amibay.com/showthread.php?92627-A2386SX-upgrade-processor-swap-question

 

[Pior]

Thank you That was a great help

 

[trixster]

There is also a dram optimiser which is in an archive called FASTDRAM.zip which you can google. This contains qdram.com which seems to speed up the dram refresh. Benchmark speeds seem only fractionally higher but Doom is perceptibly more responsive.

 

[Pior]

OK thanks for the info on the FASTDRAM.zip. I will check it out.

I solder on the TI486SXLC-G50-PQ and it works great alot faster once I added and enable the clock-doubling and cache software. What a difference

 

[trixster]

Superb! Good work

have you experimented by swapping the goldengate oscillator? A problem with the GG is that both cpu and bus derive their clock from the one oscillator, so I do not know how far the board can be over-clocked before the bus and ram start to fall over. The commodore bridgeboards have separate crystals for cpu and bus.

 

[Milesunder]

So I have had a TI 486SLC2 replace the 386 chip on my GG. Out of interest what speed should the Crystal be? My card is recognised but won’t run coming up with error code 98 “can’t find 486”. Wondering if the chip hasn’t been soldered properly or the Crystal might be incorrect.

 

[Pior]

No I have not yet replaced the goldengate oscillator. If I do change it what size do I put in place of it the same or higher. I have been noticing some hangups installing DOS 7.1 and OS 2.1 where it will lock the install and have to do a cold reboot But Dos 5.0 and 6.2 install and work fine and est programs seam to work at lest the ones I have tried....

 

[BlindGerMan]

The BIOS of the Goldengate has a 10 MHz switch for the ISA Bus, so the card itself will work with 10 MHz on ISA, if you have ISA cards working with this frequency. As the ISA bus is clocked at 8 up to 8.33 MHz normaly, you could try an oscillator with round about 20 percent more clock rate! But remember to set the ISA bus speed to low in the Goldengate BIOS!

Good Luck!

 

[Pior]

Which oscillator would it be, there are three on the board. 50 Mhz with four legs, a 24 Mhz and a 14 Mhz with two legs.

 

[trixster]

I believe the 50mhz is the cpu Crystal. I admit I was not aware of the two other oscillators - I wonder what they are for? Whereabouts are they on the board?

 

[Pior]

The 24mhz is just right of the Floppy and IDE controller chip and the 14Mhz is down below just in front of the S1 memory socket..