The RAM read speed is similar to the SiS Rabbit's, but your FSB is 5 MHz faster. Same goes for the external cache read speed. What percent of the time does is read vs. write vs. move speeds utilised for old DOS games? 60/25/15? If so, optimising for read speed would be of the greatest benefit.

Have you ran MEMTEST with your FSB at 45 MHz and with your existing memory timings? What about Win 3.1?

The results at 40MHz are also not bad. I think about 35mb/sec L1 and 23mb/sec DRAM.

I haven't done stability testing at 45MHz yet. I will tonight.

Also, this is a good place to search for 386 BIOS images.

I also found MR BIOS for Acer 1429. Somebody should try it out: http://chukaev.ru54.com/bios/3alr001.zip

This appears to be the master list of MR-BIOS versions: (for 286, 386 and 486)

http://www.matrix-bios.nl/id/mr.html

How did the stability testing go? What was your test methodology?

I haven't had time to get to it because of work.

I am having a problem related to setting the ISA clock though, because my board sets it by jumper but the BIOS wants to do it through software. Only works properly at 8MHz.

Isn't 8 MHz the ISA spec? Do you wish to run your ISA bus above or below spec?

I normally like to keep my ISA cards running in spec. However, this system is able to handle 10MHz pretty well. It's perfectly happy with the AMI. Even 12MHz seemed to work okay. With MR-BIOS the system reports no keyboard present and won't let me into the BIOS setup (though the keyboard works at the prompt) or sometimes the system won't even turn on.

It's to bad I don't have other 495SX boards anymore.

I also tested my 486DLC3 (486BL3) upgrade on this board last night. No response from the BIOS at all. Not sure why it worked on the 495SX board I sold off but not this one.

feipoa wrote:

Isn't 8 MHz the ISA spec? Do you wish to run your ISA bus above or below spec?

If i'm not mistaken the ISA spec is actually 7.159 which comes by dividing by 14.318MHz OSCI. But 8Mhz is very tolerable.

There isn't really an ISA "spec", because it changed several times over the years. The original PC and XTs ran their "ISA" slots at 4.77 MHz which was the same speed as the CPU or OSC/3. The original AT ran both the ISA and CPU bus at 6MHz using a separate 12MHz CPU crystal. The model 339 AT ran it's CPU and ISA bus at 8MHz using a separate 16MHz crystal. In ATs the OSC is still used for system timers, controllers etc, and is probably still on modern system boards.
Additionally when several manufacturers decided to get together in the late 1980s to develop EISA bus, they stated that the official operating speed of both ISA and EISA is 8MHz.
To the best of my knowledge no IBM machine runs an ISA bus at 7.159MHz, while some do run it at 4.77, 6 or 8MHz. Not sure about PS/2 ISA systems though.
The 7.159MHz setting is certainly safe to use and can be convenient when overclocking your system or using old 8-bit cards, but is by no means the official speed of ISA in my opinion. Much of what I said is confirmed here: http://en.wikipedia.org/wiki/Industry_Standard_Architecture

The legendary T-Bird: http://www.classiccomputer.de/pc/asitbird1.jpg
AMD 386SX 25MHz, 1MB(onboard)+4x1MB(SIMM) RAM, Trident TVGA 8900
pimped with an Adaptec 1542CP and IBM DSAS-3540

here comes a dumb question that's probably painfully obvious to everyone else but......how are you guys getting screenshots of speedsys and BIOS screens? I always have to point my digital camera and click for anything in true DOS.

For BIOS using my VGA capture card. Speedsys too, however it has also a save screenshot function.

Is there anyone with a Micronics Gemini 386 who can provide speedsys results?

Cyrix 486 DRx2 25/50, 1Kb L1 - 50Mhz
Intel 16-33Mhz 387DX @ 25Mhz
OPTI 25Mhz Chipset, No Cache, Unknown Mainboard with 8xSIPP Slot
8Mb SIPP Ram
4Gb Harddisk, Mitsumi FX-002? CD-Rom Drive 2x with Controllercard
Soundblaster 32 with 2Mb RAM
Ne2000 Networkcard.
3,5", 5,25" Floppy Drives.

Hmm, the performance is actually quite good for 25MHz. Care to tell us which OPTi chipset you have?

Hm need to open the Case, i will report in the next days.

Anyone else had trouble with the graphics in Speedsys? My ICL 486DX2 only shows the borders around boxes and no text. I tried with two different graphics cards with similar results. Some incompatiblity with the mainboard I presume? The program works fine with the AMD 386sx though, and it's the same Speedsys version in both cases (Smartdrv/EMM disabled).

A no name "8517 v3.21", ALi M1217-40 based Am386SX33 board, picked up cheaply, and repaired acumulator leak damage, and some minor damage to RAM sockets.
Added 4x4MB-60ns RAM 30 pin SIMMs, ATI Mach32 Ultra+ 1MB, multi-IO with 256MB CF.
Tweaked timings to max.

Peformance is surprisingly good considering a 16-bit path to memory and no cache. I wonder if your CPU would overclock to 40MHz?

Anonymous Coward wrote:

Peformance is surprisingly good considering a 16-bit path to memory and no cache. I wonder if your CPU would overclock to 40MHz?

It does...

A no name "KM-340IC Rev.H3B", Forex 411/402 based Am386DX40, 64kB cache board.
Added 4x4MB-60ns RAM 30 pin SIMMs, Tseng ET4000AX 1MB, multi-IO with 256MB CF.
Tweaked timings to max.