Help with Modified Golden Gate 486 SLC

matt3k

Well-known member
Blogger
Joined
Mar 1, 2011
Posts
1,064
Country
United States
Region
NY
I'm new to the bridgeboard world of Amiga's and was looking for help.

This one looks like it was a regular 486 SLC that the prior owner made it a SLC2 by adding a the faster Cyrix chip. Crazy hack job, but the prior owner claims it works.

I was going to put it in my 3000T with a Tseng ET4000W32i and a decent sound card, something compatible and with wave tables. Was going to use it for fun retro gaming.

My 3000T has a warp engine 060@80MHz.

1. Is the ET4000 a good card for the Goldengate?
2. What soundcard would you recommend?
3. What will I need to get started as far as software?
4. The card doesn't have ram, should I track some down?
5. I'm using 3.1.4.1 and I'm concerned about it being compatible? (I have found a few things that don't run right under it).
6. There is a fan on it that is just loose on the board, do I need the fan or will a good heatsink be good?
7. Should I consider updating to the ti chip with more cache? Does it make a big difference for retro gaming? Who does the mods?
8. Any comments on the hack job done?

Bridgeboard closeup.jpg486.jpg
 
Last edited:
Posted my advice on the eab thread :)

I'd love to know what that hack does. Does it raise the bus speed?
 
Last edited:
looks like someone got the cpu from a clip-on upgrade board and then added the clock circuit or something with some 74series and wires
 
Last edited:
How did you mount the fan to the cpu? I can't see an easy way to accomplish that?


Does the GG work with an 060 over clocked at 80MHz?
 
looks like someone got the cpu from a clip-on upgrade board and then added the clock circuit or something with some 74series and wires

I assume that it will just be a normal SLC2 with the mod? Could he have over clocked it or other improvement?
 
The SLC2 is a clock doubled chip, so you set a software flag and it runs at twice the crystal speed. In this case the GG derives it’s 25mhz from halving the 50mhz crystal and the SLC2 then runs at 25mhz if the flag isn’t set or 50 if it is.

So maybe he didn’t have the software and is setting the clock of the cpu directly using that hack?

ive found that the GG bus does not like operating with even a slight overclock - changing the 50mhz crystal to something higher results in crash city. It’s a shame the GG does not have seperate bus and cpu crystals like I think the A2386SX does
 
Last edited:
Thanks for the help.

Saw BlindGerMan 286 giving crazy results with overclocking! Seems like you would be better off buying a Commodore 286sx board and starting with that. Oh well, I'll enjoy the 486, once I get it going...
 
He couldn't remember, it was made just after he bought the card new in the 90's. He said IT added a chip and made it faster...

I would love to figure out what they did exactly to see if there is something more than over clocking.

I put it in a system and the board seems to be ok according to the Amiga ROMs anyways....
 
Last edited:
The two disks are on this website:

http://amiga.resource.cx/exp/goldengate

id love to see if it works when you’ve installed everything!

I will try it out when I get sometime this weekend and let you know!

Are the latest software versions on Amiga Resource?

I contacted the seller to see if he kept contact with the tech still. We will see.

What performance tests do you all run on the pc side?
 
See my post above

using demo3 from the ultimate doom wad with -nosound flag and two levels of green border, my GG gives 3863 gametics in 13632 realtics = 9.918 fps
 
Last edited:
On the Amiga side it’s os3.9 with bb1 and 2. On the pc side it’s dos 6.22.

once you’ve installed the GG software you can test the board by running the digger program (once cpu caches are disabled), that should output using an Amiga emulated screenmode and will show the GG bios. You can use the setup program to configure your hard disk (or hardfile if you want to use one (slow!)) and your vga card.

to hardware reset the GG when it’s running you press LAmiga RAmiga s. a normal ctrl alt delete will soft reset the GG. To quite GG back to workbench it’s LAmiga RAmiga q. To toggle back from GG to workbench but keep the GG running on the back screen, it’s LAmiga q
 
Last edited:
What is the fastest ISA card for DOS games that works in a GG:


From my searches these seem fast?
1. ET4000W32i
2. ATI Mach 64
3. Diamond Speedstar 64
4. S3 variants.
5. ATI Ultra

Any thoughts?
 
Last edited:
Unsure tbh. It is likely the GG is more cpu throttled than vga card throttled for stuff like doom, so you might see little variance between cards. But I don’t have anything other than an ATI Mach64 to check
 
I found an old hard file with DOS 6.22 that was used for PCTask.

Will that work with the GG?
 
I did a similar hack to a Commodore A2386 bridgeboard many, many years ago using the TI version of this chip. From my very vague memory, the added TTL logic chip was used to inhibit caching of certain problematic memory locations, which would otherwise have to be done by software during booting.

I also used to have a Golden Gate 486 card like yours. The fan was attached directly to the top of the CPU....no heatsink.
 
Last edited:
Back
Top Bottom