Personal computing discussed
Moderators: renee, Flying Fox, morphine
bhtooefr wrote:http://www.os2museum.com/wp/vme-broken-on-amd-ryzen/
This would be of rather minor importance - it's only going to affect 16-bit processes running in V86 mode on a 32-bit OS (or memory manager, JemmEx for FreeDOS being the cited one) - if it weren't for the fact that XP and Server 2003 execute the video BIOS in that manner. Still fairly minor - nobody's running either of those OSes on the Ryzen metal - but could be annoying for someone who needs to run one of them in a VM.
My guess as to how AMD's going to fix it? If they can't fix it properly in microcode, just disable the VME bit in the CPUID. There's only one OS where that presents a problem, Windows 2000, where it assumes VME anyway, and VIA's solution (when they were shipping silicon that didn't support VME) was to distribute a patched NTVDM with the driver package.
wingless wrote:I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.
Concupiscence wrote:wingless wrote:I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.
At this point sourcing the real hardware's just too much of a hassle. And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
Flying Fox wrote:Concupiscence wrote:wingless wrote:I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.
At this point sourcing the real hardware's just too much of a hassle. And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
Just ask Starfalcon?
Chrispy_ wrote:I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.
wingless wrote:I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.
Concupiscence wrote:Call it plainly. Voodoo 1!And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
Chrispy_ wrote:Well with the massive cash-rich giants like Intel and Microsoft both refusing to support old OSes, I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.
I suspect the solution for 16-bit software is soon going to be emulation rather than running anything natively, and I'd hope Microsoft would step up to that plate. If they don't, perhaps VMware or someone else will.
Chrispy_ wrote:Ryzen may be "x86 compatible" but both AMD and Intel have culled older OSes from their support list, Vista was the first OS that ditched V86 mode entirely and Ryzen is officially a Windows10-only product.
Like you say, a simple microcode change would stop it from happening. Whether AMD are even going to bother is another matter. I mean who would buy a multicore 64-bit processor to run a 32-bit OS emulating 16-bit via VM?!
Chrispy_ wrote:Where did AMD say that?Ryzen is officially a Windows10-only product.
Chrispy_ wrote:Ryzen may be "x86 compatible" but both AMD and Intel have culled older OSes from their support list, Vista was the first OS that ditched V86 mode entirely and Ryzen is officially a Windows10-only product.
Chrispy_ wrote:Like you say, a simple microcode change would stop it from happening. Whether AMD are even going to bother is another matter. I mean who would buy a multicore 64-bit processor to run a 32-bit OS emulating 16-bit via VM?!
bhtooefr wrote:Actually, XP x64 and Server 2003 x64 did that before Vista
meerkt wrote:Chrispy_ wrote:Where did AMD say that?Ryzen is officially a Windows10-only product.
AMD Chipset Drivers 192 MB 17.10 4/28/2017
Description:
Supports Windows 10/8.1/7 (32 & 64-bit)
Package Includes:
AMD Chipset Drivers
AMD Ryzen™ Balanced Power Plan
meerkt wrote:Chrispy_ wrote:Where did AMD say that?Ryzen is officially a Windows10-only product.
bhtooefr wrote:http://www.os2museum.com/wp/vme-broken-on-amd-ryzen/
This would be of rather minor importance - it's only going to affect 16-bit processes running in V86 mode on a 32-bit OS (or memory manager, JemmEx for FreeDOS being the cited one) - if it weren't for the fact that XP and Server 2003 execute the video BIOS in that manner. Still fairly minor - nobody's running either of those OSes on the Ryzen metal - but could be annoying for someone who needs to run one of them in a VM.
My guess as to how AMD's going to fix it? If they can't fix it properly in microcode, just disable the VME bit in the CPUID. There's only one OS where that presents a problem, Windows 2000, where it assumes VME anyway, and VIA's solution (when they were shipping silicon that didn't support VME) was to distribute a patched NTVDM with the driver package.
ronch wrote:So could this prevent running old DOS games under DOSBox? I'm still a big fan of old DOS games and those are pretty much 16-bit. Who knows, some of them may even be 8-bit like some really old titles like Dragonworld (1984).
meerkt wrote:Chrispy_ wrote:I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.
But it's officially part of x86. My guess is that they'll fix it in a future core stepping.wingless wrote:I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.
Kinda weak for 98SE, no?Concupiscence wrote:Call it plainly. Voodoo 1!And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
wingless wrote:For mid to late '90s DOS gaming it's more than adequate.
ronch wrote:I don't think DOS ran on i8080? IBM PC started with 16-bit.I'm still a big fan of old DOS games and those are pretty much 16-bit. Who knows, some of them may even be 8-bit like some really old titles like Dragonworld (1984).