> VGA is only a slightly extended superset of the EGA
People remember EGA as being planar and VGA packed/chunky in its most widely used mode 13h 320x200@256.
In reality VGA never stopped being planar internally. VGA like EGA before supports 256KB of ram, but instead of simply giving user access to linear sliding 64KB window it arranges video ram into 4 chained planes. Writing 4 consecutive pixels at 0x0 stores those in video memory 64KB apart.
Depending on the implementation all this complexity can add up. Simply turning off Chaining is not enough, but can be bypassed by engaging VESA linear modes. Effect can be miniscule:
"M13speed examines all video BIOS calls (10h.) If the call is a request for VGA mode13h (320x200 256-color), M13speed replaces the call with a request for VESA SVGA 640x400x8 (mode 100h.) ... The TSR's response to setmode13h includes issuing a VESA setmode100h (640x400 SVGA) request, reprogramming the VGA CRTC and SR registers to setup a 320x200 display field, which looks, feels, smells like MCGA 320x200."
"Without m13speed, the 9680 posted MCGA ("vidspeed L") write performance of 14mb/sec. ...loaded m13speed and re-tested my 9680's MCGA performance - 50mb/sec"
Writing 4 consecutive pixels at 0x0 stores those in video memory 64KB apart.
I don't think "64KB apart" would make much sense either, especially because of the flexibility of the VGA memory controller described in the article; they end up in 4 separate 64KB planes. Unless you're referring to the linear view of the framebuffer that post-VGA GPUs use, in which case the mapping between the planes and LFB can differ considerably between implementations: https://stackoverflow.com/questions/36269239/meaning-of-byte...
Yes. Bytes land in separate planes which afaik are 64KB apart in video memory if you would/could access it linearly. I think it was performance driven decision in the design of EGA with 4 parallel ram banks enabling 4x faster solid color fills etc. Both MCGA and VESA VBE cut all that crap out only allowing linear buffer which greatly simplified hardware interface unlocked new optimization possibilities.
All VGA clones still have to at least pretend mode 13h writes are divided into planes.
Yes. Piss is holier than holy and didnt run Justice Fund as its own private piggy bank stealing for PIS election campaigns and surveillance software to intercept PO politicians private communications. There is no reason whatsoever for former PIS prosecutor general last 7 months hiding in Hungary together with his co criminal deputy Marcin Romanowski who has been hiding there for almost two years. Former state-owned Oil giant Orlen CEO also spend some time hiding from prosecution in Hungary, what a coincidence.
Did we forget about pushing for illegal mail elections? Using state-owned companies filled with PIS politicians to finance bribes and promoting PIS? $25 billion pumped out straight to PIS coffers.
May 15, 1989
FBI SA and US Customs Agents advised Assistant US Attorney that source information and investigation had determined that Atari Corporation was importing 256K DRAMS into the US in false packing containers, and without proper import documents in violation of US import laws and contrary to import agreements between the US and the Japanese Ministry of Industry and Trade. Atari purchases large quantities of DRAMS from Japanese manufacturers for use in their Taiwanese manufacturing plants. Purchasing in Taiwan allows Atari to obtain the DRAMS at a greatly reduced price. There are strict import quotes on the DRAMS, because of Japanese flooding of the market in years previously but there are no import duties. By shipping the DRAMS in the U.S., Atari can thereby increase the price by approximately four times their purchase price. The original manufacturers, whether Fujitsu or Mitsubishi would not be allowed to import this quantity at this price into the U.S., because this practice stifles U.S. manufacturers.
Investigation determined that Atari was importing large quantities, 150,000 or more a wekk into the U.S. since May,1988. None were declared through U.S. Customs, and it appears telexes and telephones were used to order specific quantities in furtherance of this scheme.
Based on the above, Assistant US Attorney stated he would consider prosecution of this matter under the Wire Fraud Statutes or 1001 Falsification of Import Documents.
SOURCE: FBI Case 87A-SF-40454, Pages 42-43
People remember EGA as being planar and VGA packed/chunky in its most widely used mode 13h 320x200@256.
In reality VGA never stopped being planar internally. VGA like EGA before supports 256KB of ram, but instead of simply giving user access to linear sliding 64KB window it arranges video ram into 4 chained planes. Writing 4 consecutive pixels at 0x0 stores those in video memory 64KB apart.
Depending on the implementation all this complexity can add up. Simply turning off Chaining is not enough, but can be bypassed by engaging VESA linear modes. Effect can be miniscule:
Toshiba Satellite T2130CS CT65545 https://www.youtube.com/watch?v=7PjA6PfyWW8 Mode Y: 28 fps. 13h: 36 fps. VESA: 37 fps
be significant:
SiS 6326 PCI https://www.youtube.com/watch?v=minIT5dBCVQ Mode Y: 55 fps. 13h: 59 fps. VBE2 (LFB): 75 fps
or outright massive:
Rendition Veritè V2200 (internally a MIPS based DSP emulates VGA core in software) https://www.youtube.com/watch?v=6unNuPympE4 Mode Y: 14 fps. 13h: 59 fps. VBE2 (LFB, PM): 305 fps!
There was even a Tweak released for one vendor (Trident) http://www.geocities.ws/liaor2/myutil/m13speed.html that intercepted setting mode 13h and switched it for custom VESA underneath.
"M13speed examines all video BIOS calls (10h.) If the call is a request for VGA mode13h (320x200 256-color), M13speed replaces the call with a request for VESA SVGA 640x400x8 (mode 100h.) ... The TSR's response to setmode13h includes issuing a VESA setmode100h (640x400 SVGA) request, reprogramming the VGA CRTC and SR registers to setup a 320x200 display field, which looks, feels, smells like MCGA 320x200."
"Without m13speed, the 9680 posted MCGA ("vidspeed L") write performance of 14mb/sec. ...loaded m13speed and re-tested my 9680's MCGA performance - 50mb/sec"
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