VOGONS


First post, by Anonymous Coward

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Does anyone have any documentation about register programming for this chipset? In the backup of the American Megatrends website that has BIOS programming for all kinds of chipsets, documents for Acer parts are strangely missing. I say this is strange because AMIBIOS was quite popular on 386 and 486 boards with Acer (ALi) chipsets.

Something else that's pretty interesting is that in this thread: "Bioteq" chipset, Eep386 claimed that while working on a Biostar MB1433-AEA based on the FTDI chipset, he discovered "Acer" stenciled into the PCB under the chipset while doing what I guess must have been hot air work. He tested an Acer M1419 BIOS, which apparently worked. So it seems that the FTDI chipset must be some kind of clone of the M1419. I have since tested an Award BIOS V4.50 for M1419 in my Biostar MB1340-AEA, and can confirm it works perfectly.
American Megatrend's website interestingly did have BIOS programming for the FTDI (FTD, mislabled FDT) chipset. Similarly Microid Research also did not make a BIOS for the ALi M1419, but did for the FTDI, which is sadly missing from our archives.

In the M1419 AMIBIOSes I have tried, there is nothing in the setup that allows adjustment of the RAM or cache timings. Similarly, in the AMI documentation for the FTDI chipset I can find no registers programming information for these features. Does anyone know if either or both of these chipsets handles this automatically, or if there are some hidden/undocumented chipset registers?

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 1 of 5, by jakethompson1

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I just looked too and the AMI, Award, and Acer BIOSes for this look pretty sparse.
Since they are uncompressed you can run a "strings" utility (e.g. on Linux or the Sysinternals version for Windows) and look for interesting strings/possible hidden options even if you don't have or can't open them in modbin, amibcp, etc.
It looks like the Acer BIOS has a hidden memory type settings, where "Slow" is for 80 ns or slower. That's probably part of what you are looking for. [edit: it's not hidden, I just didn't know about Page Down] But I see nothing at all about 486 cache burst settings.

Another indication that not much is known about this chipset is there is no emulation for it in PCem or 86box.

Reply 2 of 5, by Anonymous Coward

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I didn't see the Acer BIOS for the M1419. Do you know what kind of system it came from?
Too bad there aren't any utilities for dealing with Acer BIOS. I have a pretty sweet dual Pentium system that has an Acer BIOS, and I'm not aware of any replacement options.

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 3 of 5, by Anonymous Coward

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In the FTDI chipset "manual" I did find some registers to control 486 burst mode timings:

36h
Bit 7 Internal local bus control
0 Disabled
1 Enabled
Bit 6 486 burst mode
0 Disabled
1 Enabled
Bits 5-4 Low speed rate selection
00 1:6 01 1:2
10 1:3 11 1:4
Bit 3 Cache write algorithm
0 Wrt/Thru
1 Wrt/Back
Bit 2 Refresh type
0 AT Bus
1 Hidden
Bits 1-0 486 burst mode timing
00 3-2-2-2 01 3-1-1-1
10 2-2-2-2 11 2-1-1-1

This may or may not work on the Acer M1419 chipset.

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 4 of 5, by Eep386

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Thank you for finding that snippet about the write back/thru bit!
I'd like to try punching that into CTCHIP to see if I can get these ALi M1419 386DX boards to stop using broken write back. 😅

Life isn't long enough to re-enable every hidden option in every BIOS on every board... 🙁

Reply 5 of 5, by BitWrangler

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This is all I get in Advanced Chipset menu on https://theretroweb.com/motherboards/s/acer-i … gxi-model-i433a

GxiSettingvgabench.jpg

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.