UMC haha nice find 😀

egbertjan wrote on 2020-10-18, 15:49:

I would also like to know if the tseng et4000 ax is a 512kb or a 1mb card. How can I find out?

44256 chip = 256K * 4 bits
So you have 512 KB total.
If there are artifacts, it would be a good idea to replace those chips with tested-good ones, preferably full 1 MB.

The Tseng card has 4 256Kx4 DRAM chips in it, so has 512KB DRAM

Cool, I had the same dilemma some time back.
I had to choose between the 408, the ET4000ax and V7 5424.
I actually tested all three with Phills bench series and all cards seem to be limited by the ISA bus. My 486 DX50 (not a DX2) makes them perform equally fast, with about 1% difference max.
The UMC has a disadvantage: to get vesa modes you need to load a TSR, otherwise it simply won't do anything else but plain VGA modes (but still fast).

Since that system is loaded with UMC chips (chipset and I/o), I decided to keep the UMC in and settled with the TSR.

About the et: get yourself some replacement ram chips and replace all of them all along with adding new ones to the empty sockets. Your chips are rated 80ns, but I'd look for 70ns at minimum, preferably 60ns.

Grzyb wrote on 2020-10-18, 17:02:

44256 chip = 256K * 4 bits So you have 512 KB total. If there are artifacts, it would be a good idea to replace those chips with […]
Show full quote

egbertjan wrote on 2020-10-18, 15:49:

I would also like to know if the tseng et4000 ax is a 512kb or a 1mb card. How can I find out?

44256 chip = 256K * 4 bits
So you have 512 KB total.
If there are artifacts, it would be a good idea to replace those chips with tested-good ones, preferably full 1 MB.

Thanks, do you have a suggestion which chips I should buy?

waterbeesje wrote on 2020-10-18, 17:21:

Cool, I had the same dilemma some time back. I had to choose between the 408, the ET4000ax and V7 5424. I actually tested all th […]
Show full quote

Cool, I had the same dilemma some time back.
I had to choose between the 408, the ET4000ax and V7 5424.
I actually tested all three with Phills bench series and all cards seem to be limited by the ISA bus. My 486 DX50 (not a DX2) makes them perform equally fast, with about 1% difference max.
The UMC has a disadvantage: to get vesa modes you need to load a TSR, otherwise it simply won't do anything else but plain VGA modes (but still fast).

Since that system is loaded with UMC chips (chipset and I/o), I decided to keep the UMC in and settled with the TSR.

About the et: get yourself some replacement ram chips and replace all of them all along with adding new ones to the empty sockets. Your chips are rated 80ns, but I'd look for 70ns at minimum, preferably 60ns.

Thanks, but which TSR did you use?

egbertjan wrote on 2020-10-18, 20:24:

Thanks, do you have a suggestion which chips I should buy?

Identical to those currently installed.
If you can't find identical, than any FPM DRAM 256Kx4 DIP20 80ns-or-faster should work.

As for the speed...
http://vgamuseum.info/index.php/companies/ite … -tseng-et4000ax - as you can see, the chips used are mostly 70ns or 80ns, one card has 60ns
but I don't know if there's some gain from using the faster ones.

Sorry to hijack this topic a bit, does the VGA BIOS detect the speed of the memory chips installed? Or how does that work. 😀

PD2JK wrote on 2020-10-19, 05:07:

Sorry to hijack this topic a bit, does the VGA BIOS detect the speed of the memory chips installed? Or how does that work. 😀

The VGA BIOS on those cards does not detect the chips' speed. All chips are operated at a predefined speed regardless of their rated speed.
If the chip is faster it won't show. If it can't keep up it will malfunction.

egbertjan wrote on 2020-10-18, 20:27:

waterbeesje wrote on 2020-10-18, 17:21:

Cool, I had the same dilemma some time back. I had to choose between the 408, the ET4000ax and V7 5424. I actually tested all th […]
Show full quote

Cool, I had the same dilemma some time back.
I had to choose between the 408, the ET4000ax and V7 5424.
I actually tested all three with Phills bench series and all cards seem to be limited by the ISA bus. My 486 DX50 (not a DX2) makes them perform equally fast, with about 1% difference max.
The UMC has a disadvantage: to get vesa modes you need to load a TSR, otherwise it simply won't do anything else but plain VGA modes (but still fast).

Since that system is loaded with UMC chips (chipset and I/o), I decided to keep the UMC in and settled with the TSR.

About the et: get yourself some replacement ram chips and replace all of them all along with adding new ones to the empty sockets. Your chips are rated 80ns, but I'd look for 70ns at minimum, preferably 60ns.

Thanks, but which TSR did you use?

The disk image attached here 😀
Not mine, just found somewhere on the net.
It contains all kinds of drivers.
(You may open the exe with a zip program to see what files you'll need)

I have that exact ET4000AX card and even though I am not saying it is slow, but it is the slowest ET4000AX card I have. The 2 other ET4000AX cards I have are faster. I have tried changing the jumpers when I tested the cards and I have not noticed changing the jumpers to cause that kind of issues.

I have seen slow ET4000 cards too. Yesterday I was lucky, it sped up when I changed JP1. Of course it's different on various cards. Maybe sometimes none of them work.

Oh yeah, some ET4000 cards come with a jumper to set wait states - http://www.uncreativelabs.de/th99/v/U-Z/50623.htm
The card this thread is about, however, lacks the pins for JP1 - perhaps it's factory-configured for 1WS, in order to work with the slow 80ns memory?

alvaro84 wrote on 2020-10-20, 03:28:

I have seen slow ET4000 cards too. Yesterday I was lucky, it sped up when I changed JP1. Of course it's different on various cards. Maybe sometimes none of them work.

I have not been able to figure out what makes one ET4000AX card faster than another. All 3 cards that I have are different speeds and this one that I have in the picture is clearly the fastest out of 3 while the card that which picture was in the first post of this thread is the slowest.

Baoran wrote on 2020-10-20, 05:05:

I have not been able to figure out what makes one ET4000AX card faster than another. All 3 cards that I have are different speeds and this one that I have in the picture is clearly the fastest out of 3 while the card that which picture was in the first post of this thread is the slowest.

It seems to be obvious: the card with 60ns DRAM is the fastest, the one with 80ns is the slowest.
But the question remains: how exactly are DRAM access times controlled on such cards?
Is it just jumpers/hardwired? Or something in the VGA BIOS?

Grzyb wrote on 2020-10-20, 07:15:

It seems to be obvious: the card with 60ns DRAM is the fastest, the one with 80ns is the slowest. But the question remains: how […]
Show full quote

Baoran wrote on 2020-10-20, 05:05:

I have not been able to figure out what makes one ET4000AX card faster than another. All 3 cards that I have are different speeds and this one that I have in the picture is clearly the fastest out of 3 while the card that which picture was in the first post of this thread is the slowest.

It seems to be obvious: the card with 60ns DRAM is the fastest, the one with 80ns is the slowest.
But the question remains: how exactly are DRAM access times controlled on such cards?
Is it just jumpers/hardwired? Or something in the VGA BIOS?

It isn't as simple because it beats a diamond speedstar card that also has same speed ram.

On my Tseng ET4000AX are 4 of these memorychips: KM44C256BP-8. I suppose that means they are 80 nSec. Would it be possible to replace these with the chips on the card above, the HY534256ALS-60, so that my card becomes faster?

Could it be that faster memory and/or more memory solve the problem with artefacts?

egbertjan wrote on 2020-10-21, 17:07:

On my Tseng ET4000AX are 4 of these memorychips: KM44C256BP-8. I suppose that means they are 80 nSec. Would it be possible to replace these with the chips on the card above, the HY534256ALS-60, so that my card becomes faster?

Could it be that faster memory and/or more memory solve the problem with artefacts?

I don't know if memory makes it faster because it seems there are faster and slower cards with same memory speed too. The artifacts would only disappear if the memory was faulty to begin with, so if you can you could try similar ram from another working card to test that before buying more ram for it to make sure.