Video timing/sync parameters for non-PC workstations - Page 1
Forum section: electronics / general

author: Scratch.HTF
author_rank: Regular Contributor
timestamp: May 16, 2020, 01:31:41 am
content: I am currently building a video sync trigger which can identify a particular video mode (and set parameters automatically), so therefore, I am looking for information on Horizontal/Vertical frequencies (with at least one decimal place for Vertical frequency if available)/sync polarities with their corresponding resolutions for HP/DEC/VAX/Apollo/SGI/Sun and other non-PC workstations for each resolution which these parameters are not covered by the VESA DMT standard.Also, I am after Horizontal/Vertical frequencies and sync polarities for the Apple Portrait Display (640x870).

author: fragile
author_rank: Contributor
timestamp: May 28, 2020, 02:11:44 pm
content: I think it matters more how the machine reads the information, or how to present it. Monitors work the same way no matter what their connected to. There is a utility, cvt, for Linux, that outputs 'modelines' for a given resolution and refresh rate. If you could translate those, it might get you what you need.

author: Wuerstchenhund
author_rank: Super Contributor
timestamp: May 29, 2020, 08:52:55 am
content: Quote from: Scratch.HTF on May 16, 2020, 01:31:41 amI don't think I still have the documentation from back then (I dumped this years ago) but I don't believe there were that many differences to what PCs were using.From memory:HP:HP's 9000 Series PA-RISC workstations stuck to common VESA modes with separate sync as you find on PCs (the graphics mode could be set in the firmware menu and depending on the graphics supported a list of modes from VGA to SXGA or above).The older M68k based workstations (300/400 Series) used standard VESA modes but with Sync on Green (SOG). In general, if it's 13W3 then it's SoG, if it's VGA or EVC then it's separate sync.DEC:DEC AXP (Alpha) with EISA and PCI also stuck with common VESA modes and separate sync as on PCs (not surprising since most of the graphics adapters were actually PC graphics cards).The DEC 3000 AXP however used SoG if I remember right (3W3 connectors?). I believe VAXes used the same.SGI:Standard VESA modes (usually XGA and above, depending on the graphics hardware) with SoG (13W3, resolution selected via the utility pins) for all MIPS/IRIX machines which aren't based on PCI (which had standard DVI) except the O2 (which had a VGA connector but sent out SoG in addition to separate sync so the green signal often had some visible bias on monitors which didn't filter out the sync component).IBM:IBM RS/6000 aka pSeries (POWER/PowerPC): MCA models used standard VESA modes (usually XGA and above) with SoG (13W3, most cards had a single fixed mode), PCI models used standard VESA modes with separate sync (pretty much like PCs) or DVI.Sun/Oracle:SPARC based machines with 13W3 connector (resolution determined via utility pins) used composite sync and non-VESA resolutions. Later machines (UltraSPARC based) with PCI/PCIe also offered newer graphics adapters which had VGA or DVI instead.In short, most of the machines used the same VESA modes and signalling as contemporary PCs. For the others, you could examine the X11 modelines in Linux distros specific for those platforms, which should be pre-configured with the necessary non-VESA parameters.