First post, by ychh0
During installation Windows98 with ATI Mach64 VLB 4MB, I found that default driver of Windows98SE support up to 1600*1200*16bit but ATI official driver 3.03 support only up to 1280*1024*24bit.
After checking informations around the internet, I found several sources about ATI Mach64 GX family, especially ATI Mach64 Graphics Pro Turbo 1600.
1. VOGONS WIKI
- Graphics Pro Turbo 1600 (fast RAMDAC,PCI-only)
2. ATI Version 3.1 CD User’s Guide
http://www.vgamuseum.info/index.php/component … 2471f4373a9df1a
- There are three version of VRAM Mach64 variants ; ATI Graphics Pro Turbo 1600, ATI Graphics Pro Turbo and Winturbo
- 1600*1200 modes are supported by ATI Graphics Pro Turbo 1600 version only (Table 1)
3. Mach64 X Server Support
- Each Mach64 VLB Variant use different ramdac.
1) ATI Graphics Pro Turbo/Winturbo : Normally ATI68860 or ATI68880
2) ATI Graphics Pro Turbo 1600 : IBM RGB514
I checked my VLB Winturbo and VLB Graphics Pro Turbo, it seems both equipped 68860. I have not seen any Mach64 with IBM RGB514 ramdac and wonder what’s the difference between those two ramdacs.
At first I thought I installed wrong windows driver , and after seeking some infos including aboves I guess 1280*1024 is original limit of driver of normal Graphics Pro Turbo. (According to VOGONS WIKI there is no Graphics Pro Turbo 1600 VLB) Windows98SE default driver may be the one that those two drivers are incorporated into.
Then could we infer ATI intentionally set resolution limit for Graphics Pro Turbo and actually two ramdacs have little difference ? Normal ATI Mach64 Graphics Pro Turbo using ATI68860 ramdac also has no problem in using 1600*1200*16bit?
I played around several hours with 1600*1200*16bit setting, there was no visible problem.
* Attached is my ATI Mach64 Graphics Pro Turbo 4MB VLB