More riva128 nitpicks

Author: richardg867

_posts/2025-02-25-riva128-part-1.md

@@ -42,7 +42,7 @@ This is the first part in a series of blog posts that aims to demystify, once an
 
 NVIDIA was conceived in 1992 by three LSI Logic and Sun Microsystems engineers: Jensen Huang (now one of the world's richest men, still the CEO and, apparently, mobbed by fans in his country of birth Taiwan), Curtis Priem (whose boss almost convinced him to work on Java instead of founding the company) and Chris Malachowsky (a veteran of graphics chip development). They saw a business opportunity in the PC graphics and audio market, which was dominated by low-end, high-volume players such as S3 Graphics, Tseng Labs, Cirrus Logic and Matrox[^matrox]. The company was formally founded on April 5, 1993, after all three left their jobs at LSI Logic and Sun between December 1992 and March 1993.
 
-[^matrox]: Only Matrox is both still around and still in the graphics space, after exiting the consumer market in 2003, ceasing to design graphics cards entirely in 2014, and recently coming back with Intel Arc-based designs. Cirrus Logic is still around as an audio chip designer, stemming from their acquisition of Crystal in the 1990s.
+[^matrox]: Only Matrox is both still around and still in the graphics space, after exiting the consumer market in 2003 and ceasing to design graphics cards entirely from 2014 until their recent comeback with Intel Arc-based products. Cirrus Logic is still around as an audio chip designer, stemming from their acquisition of Crystal in 1991.
 
 After the requisite $3 million of venture capital funding was acquired (a little nepotism owing to their reputation helped), work immediately began on a first generation graphics chip; this was one of the first of a rush of dozens of companies attempting to develop graphics cards - both established players in the 2D graphics market such as Number Nine and S3, and new companies, almost all of which no longer exist - many of which failed to even release a single graphics card. The name was initially GXNV for "GX next version", after a graphics chip Malachowsky led the development of at Sun, but Huang requested him to rename the chip to NV1 in order to not get sued. This also inspired the name of the company - NVIDIA, after other names such as "Primal Graphics" and "Huaprimal" were considered and rejected, and their originally chosen name of "Invision" turned out to have been trademarked by a toilet paper company.
 
@@ -58,7 +58,7 @@ In order to achieve this, many techniques had to be used that ultimately comprom
 
 Additionally, the fundamental implementation of 3D rendering used quad patching instead of traditional triangle-based approaches; this has very advantageous implications for things like curved surfaces, and may have been a very effective design for the CAD/CAM customers purchasing more high end 3D products, however, it turned out to not be particularly useful at all for the actually intended target market of gaming. There was also a total lack of Sound Blaster compatibility (very much a requirement for half-decent audio in games back then) in the audio engine, and VGA compatibility was very slow and partially emulated, which led to slow performance in the games people *actually played*, unless your favourite game was a crappier, slower version of *Descent*, *Virtua Cop* or *Daytona USA* for some reason. Another body blow to NVIDIA was received when Microsoft released Direct3D in 1996 with DirectX 2.0, which not only used triangles, but also became the standard 3D API and deprecated all of the numerous non-OpenGL proprietary APIs of the time, including S3's S3D and MeTaL[^metal], ATI's 3DCIF, and NVIDIA's own NVLIB.
 
-[^metal]: S3's later API for the Savage family, not to be confused with Apple's Metal from many years later.
+[^metal]: S3's later proprietary API for the Savage family, not to be confused with Apple's Metal from many years later.
 
 The upshot of all of this was what can be understood as nothing less than the total failure of NVIDIA to sell or convince anyone to develop for NV1 in any way, despite its innovative silicon design. While Diamond Multimedia purchased 250,000 chips to place into their "Edge 3D" series of cards, and other manufacturers produced cards in smaller quantities, barely any of them sold, and those that did sell were often returned, leading to the chips themselves being returned to NVIDIA and hundreds of thousands of chips sitting simply unused in warehouses. Barely any NV1-capable software was released, with the few pieces of software that do exist coming via a partnership with Sega (more on that later), while most others were forced to run under software emulators for Direct3D (or other APIs) written by Priem, which were made possible by the software architecture NVIDIA chose for their drivers, but were slower and worse-looking than software rendering, buggy, and generally extremely unappealing.
 
@@ -82,7 +82,7 @@ The reasons for 3dfx being able to design such an effective GPU when all others
 
 [^sgi]: By 1997, SGI had over 15 years of experience in developing graphics hardware, while also suffering from rampant mismanagement and experiencing the start of what would later prove to be their terminal decline.
 
-[^edge]: Where a triangle is converted into "spans" of horizontal lines, and the positions of nearby vertexes are used to determine the span's start and end positions.
+[^edge]: In the edge interpolation process, a triangle is converted into "spans" of horizontal lines, and the positions of nearby vertexes are used to determine the span's start and end positions.
 
 [^span]: To simplify a complex topic, in a GPU of this era, span interpolation generally involves Z-buffering (also known as depth buffering), sorting polygons back to front, and color buffering, storing the color of each pixel sent to the screen in a buffer which allows for blending and alpha transparency. Some GPUs do not implement a Z-buffer and delegate polygon sorting to software instead; examples include the NV1, original ATI Rage and the PlayStation 1's Geometry Transformation Engine.
 
@@ -94,7 +94,7 @@ It was with these financial, competitive and time constraints in mind that desig
 
 After the NV2 disaster, the company made several calls on the NV3's design that turned out to be very good decisions. First, they acquiesced to Sega's advice (which they might have already done to save the Mutara V08/NV2, but it was too late) and moved to an inverse texture mapping triangle-based model, although some remnants of the original quad patching design remain. The unused DRM functionality was also remove, which may have been assisted by David Kirk[^dkirk] taking over from Curtis Priem as chief designer, as Priem insisted on including the DRM functionality with the NV1, citing piracy issues with the game he had written as a demo of the Malachowsky-designed GX GPU back when he worked at Sun.
 
-[^dkirk]: David Kirk is perhaps notable as a "Special Thanks" credit on *Gex* and the producer of the truly unparalleled *3D Baseball* on the Sega Saturn during his time at Crystal Dynamics.
+[^dkirk]: David Kirk is perhaps notable as a "Special Thanks" credit on *Gex* and the producer of the truly unparalleled *3D Baseball* on Sega Saturn during his time at Crystal Dynamics.
 
 Another decision that turned out to pay very large dividends was deciding to forgo a native API entirely and build the card around accelerating the most popular graphical APIs, which led to an initial focus on Direct3D, although OpenGL drivers were first publicly released in alpha form in December 1997 and fully in early 1998. DirectX 3.0 was the initial target, and after 4.0 was [cancelled due to lack of developer interest in its new functionality](https://devblogs.microsoft.com/oldnewthing/20040122-00/?p=40963), 5.0 came out late during development of the chip, which turned out to be mostly compliant, with the exception of some blending modes such as additive blending which Jensen Huang later claimed was due to Microsoft not giving them the specification in time. This compliance was made much easier by the design of their driver, which allowed (and still allows) graphical APIs to be plugged in as "clients" to the Resource Manager kernel; as I mentioned earlier, this will be explained in full detail later.
 
@@ -106,7 +106,7 @@ The initial revision of the architecture appears to have been completed in Janua
 
 Luckily for NVIDIA, the NV3 chip worked well enough to be sold to their board partners (almost certainly thanks to that hardware simulation package), and the company survived. Most accounts indicate they were only three or four weeks away from bankruptcy; when 3dfx saw the RIVA 128 at its reveal at the CGDC 1997 conference, one founder responded with "you guys are still around?", considering 3dfx almost *bought* NVIDIA effectively for the purpose of killing the company as a theoretical competitor, but NVIDIA refused as they assumed they would be bankrupt within months anyway. However, this revision A of the chip was not the one NVIDIA actually commercialised; SGS-Thomson dropped their plans for the STG-3000 at some point, which led NVIDIA, now flush with cash[^revenue], to create a new revision of the chip to remove the sound functionality (although some parts remained), fix some errata and make other minor adjustments to the silicon.
 
-[^revenue]: NVIDIA's revenue in the first nine months of 1997 was only $5.5 million, but skyrocketed up to $23.5 million in the last three months, which correspond to the first three months of the RIVA 128's availability, owing to the numerous sales of chips to add-in board partners.
+[^revenue]: NVIDIA's revenue in the first nine months of 1997 was only $5.5 million, but skyrocketed up to $23.5 million in the last three months, corresponding to the first three months of the RIVA 128's availability, owing to the numerous sales of chips to add-in board partners.
 
 The chip was respun, with the revision B silicon being completed in October 1997 and presumably available a month or two later; it is most likely that some revision A cards were sold at retail, but based on the dates, these would have to be very early units[^stb], with the earliest NVIDIA RIVA 128 drivers that I have discovered (labelled as "Version 0.75" and also doubling as the only NV1 drivers for Windows NT) being dated August 1997, and reviews starting to drop on websites such as AnandTech in the first half of September 1997. There are no known drivers available for the audio functionality in the revision A RIVA 128, so anyone wishing to use it would have to write custom drivers.