UDMA-2 driver for DOS!

[krick]

I just ran across this page that features a free UDMA-2 driver for DOS...

http://johnson.tmfc.net/freedos/udma.html


Has anybody tried this with DOS MAME?

Does it make any difference in the load times?

[Thenasty]

Does it make any difference in the load times?

BIG TIME...
For Test in my Cab: Pc Specs on my WWW page.

Loading Pacman without UDMA
13 seconds
with UDMA
4 seconds

Loading Kof2002 without udma
35 seconds
with udma
15 seconds

I'm gonna try this one. I'm using a different UDMA.

Here is the one I use, its the version 70

http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/dos/udma/


*edit*
just tried and compared to the one I use, don't see a diff....Both loads same times on above said games.

[NickS]

Does it make any difference in the load times?

BIG TIME...
For Test in my Cab: Pc Specs on my WWW page.

Loading Pacman without UDMA
13 seconds
with UDMA
4 seconds

Loading Kof2002 without udma
35 seconds
with udma
15 seconds

I'm gonna try this one. I'm using a different UDMA.

Here is the one I use, its the version 70

http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/dos/udma/


*edit*
just tried and compared to the one I use, don't see a diff....Both loads same times on above said games.

This sounds interesting. What is UDMa?. I have never heard of it before.

[krick]

This sounds interesting. What is UDMa?. I have never heard of it before.

Google to the rescue...

http://www.pcguide.com/ref/hdd/if/ide/modesUDMA-c.html

DOS normally uses PIO modes...

http://www.pcguide.com/ref/hdd/if/ide/modesPIO-c.html

"PIO modes do not require any special drivers under normal circumstances; support for them is built into the system BIOS. This universal support, along with their conceptual simplicity, is why they were traditionally the default way that most drives are used. Today, however, PIO is just not up to handling modern drives, which use Ultra DMA to keep the load on the CPU down and to allow access to Ultra DMA's much higher performance. Support for PIO modes is still universal on almost all systems and drives made since the mid-1990s, for backwards compatibility. It is used, for example, as a "last resort" when driver or software issues cause problems with Ultra DMA accesses."

[krick]

Here is the one I use, its the version 70

http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/dos/udma/

I don't think this affects you but just in case...

http://sourceforge.net/forum/forum.php?forum_id=505366
Jack Ellis writes: "I have discovered a NASTY problem in the UDMA2/UDMA2S drivers. The stack-switch logic in those drivers could cause a CRASH on a Non-Maskable Interrupt (NMI)! Although no-longer active in FreeDOS, my "ethics" force me to release the file UDMA2_27.ZIP containing V2.7 UDMA2/UDMA2S and V8.2 UDMA/UDMAJR, which fixes this problem. Users of UDMA2 and UDMA2S should update to the V2.7 drivers IMMEDIATELY, as the NMI problem in older versions is CRITICAL!! UDMA/UDMAJR users do not need to update, since those drivers have no changes except version and date."