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Kalvan

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Kalvan last won the day on September 10 2021

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  1. Well, the Commodore Disc Drive subsystem was originally engineered to be Daisy-Chainable, and the SD Card can hold a lor of data...
  2. How many monitors at that resolution have scan multiplier hardware? It would be awkard to have the image to occupy the central 1/144 of screen real estate with the rest being a very black "picture frame" effect.
  3. Well, thoretically, you could get a monitor with a VESA mounting, code your game assets as if that game was on a vertical resolution, rotate the SNES controller directional cross response coding ninety degrees, and when you run the program, rotate the monitor to match. It's an imperfect solution, but if you want to do vertically scrolling shoot'em ups, or portrait orientd puzzle or maze games without having to deal with letterboxing, it seems to be the only bet.
  4. Well, the original Nintendo Famicom used a 60 pin pinout, as did the Atari 2600. Since the compression method of the Nintendo S-DD1 chip has been cracked, I think that 512K should be plenty for a cartridge slot, so long as that chip (or a softcore of it on an FPGA) is on a plugged in expansion card. So long as the expansion architecture allows expansion cards to augment, rather than simply replace the capabilities of VERA and the sound interface (merely removing scanline limits and/or allowing the display of all sprites at maximum size, or adding in an extra wavetable or PCM chip while still allowing normal use of the geometry channels and the YM2151, as examples), and preferably without requiring their own specific outputs to the monitor and/or speakers, I'll be happy indeed.
  5. Well, I'd say personally that it's missing Atari's POKEY, HARVEY, AMY*, and JERRY^, various Midway and Williams arcade sound boards, and various Ensoniq wavetable and PCM chips. *HARVEY is a speach syhthesis chip based on then licensed technology from General Instruments. It was used in I, Robot, and the first motherboard versions of Marble Madness and Guantlet. AMY was an additive synthesis chip using either 64 or 128 ocilators and a 16K control ROM, meant to be used in 8 or 16 channel, 8 operator mode. It was never used, but there's a whole lot of documantation on how it worked on the Wayback Machine. ^JERRY was the sound chip of the Atari Jaguar. It featured 16 channels of 12-bit (64x64) wavetable synthesis, 16 channels of 4 operator FM synthesis, and 4 channels of 8-bit PCM synthesis with a max sample rate of 48,000 KHz.
  6. Now that the backplane has (seemingly) been finalized with the deletion of the on-board User Port, someone needs to do some feature (preferably on YouTube) involving cases supporting the Mini-ATX form factor with backplane spaces that fit the board (including the Super NES controller jacks) and four full-height expansion slots in a position that fits the orientation of board's slots.
  7. I think at least one of those boards should go to [link removed]. This way he can resume incorporating the Commander X16 into his lessons on YouTube.
  8. Mr. Murray mentioned a hypotheical maximum of 256 sprites, or double the specification published in the FAQ. Was this a faux pas, or does the specification there need to be updated beyond the deletion of one of the VIAs?
  9. Hypothetical question for the development team: If someone else were to do another Wavicle-style home brew of a Commander X16 motherboard, and the only difference (as far as end-user hardware and software interface is concerned) is that it returns that second VIA to its place on the the motherboard and its place in the port architecture and memory map, and further assuming the screwdriver that the user port sonnected up somehow matches the planned Official User Port expansion card's pinout, voltage, signal, and bandwidth profiles exactly, would either that second VIA in its original position, or the User Port in its position among the circuitry break software compatiblity with the port architecture and/or memory map the Commander X16 system in its latest hardware and systems software specification, and/or would the presence of that second VIA and/or the User Port wired to it steal CPU cycles or otherwise interfere with Audio, Video, or I/O timing in any way, shape or form? I ask this question because, as there are only four expansion slots expansion, and there is no other analogue to, say, cartridge slots on the motherboard, each individual expansion slot represents precious, extremely limited system real estate. I had several concepts for Commander X16 expansion cards in my head, and relegating the User Port to an expansion card cuts into the basic expandability of the machine by at least 2/5 (1 fifth for the expansion slot itself, the second for the missing User Port/Header on the motherboard itself). I know, one could theoretically reclaim some of that expanability by hacking the Commodore Datasette and/or Floppy Drive ports, but those appear only useful for software medium interface.
  10. True, however, the 65816 features 16-bit integer instruction arguments and register sizes.
  11. Since I don't consider the Panasonic MSX Turbo-R Machines to be 8-bit computers (the ASCII R800 featured 16-bit integer instruction arguments, registers, and at least one 16-bit data bus), the 8-bit computers with the most standard RAM would be the final production year Tandy CoCo 3 and Fujitsu FM-77, with 512-640K system RAM each (plus 128-384K separate VideoRAM in the case of the FM-77 AV40 Level 3). That said, the Apple IIc+ and IIe Anniversary Edition, Sharp X-1 Turbo Z and X, and NEC PC8816/18 have O/S memory maps capable of addressing up to 2MB, and Atari 8-bit computers equipped with the FREDDIE MMU/DMA can address up to 4MB. Back in the day, two full megabytes of High RAM+124K Video RAM, 4K PCM Buffer, and 64K Low RAM would together be seen as overkill until Ca. 1990-91, with only the Apple IIGS and Amiga 750 and then 1200 possessing similar memory amounts among contemporary non-PC Clone competition.* *I do not consider the Macintosh III and Quadra, Sharp X68000, High End Amigas, or Acorn Archimedes A4000/A6000 series to be anything close to hypothetical market segment competitors.
  12. I had a wild, wacky idea that you might want to follow up on: How about a tilemode consisting of tiles 36 horzontal X 28 vertical pixels. In a 400x225 16:9 aspect ratio display, with the leftover columns and rows used for line buffering, you get 11x8, or 88 tiles per screen. Each tile would consist of four stacks of 7 pixels, 36 stacks wide. You can map the biits of each stack so that 7 bits are used to map colors from a given CLUT, with an eighth set of seven bits used to select the CLUT. This means that you can have a hypothetical maximum of 16,192 colors (128 CLUTs of 128 colors each) onscreen, and with Video RAM at 128K mapped half and half between the tile data and the scrolling field tile map, there's room for 74 unique tiles and a screen map of 256x256 tiles in a single field, or 23x32 screens (737 total) at that 16:9 aspect ratio. If you reduce the pixel bitwidth, you can have even more tiles and/or an even larger scrolling field. Of course, one drawback is the memory requirement for all those CLUTs, which may cut into either the tile data or the screen tile map. And this still doesn't account for necessary Video RAM for BOBs...
  13. It looks like you can either take two clock cycles to use the DMA to use the Dual-Port RAM as audio buffer, or else use the DMA or the CPU to take four cycles (at least) to use the DDR2 as sound RAM, which may be necessary if you've exceeded your total sprite, or scanline limit, and wanted to add in some BOBs as extra enemies, bullets, fireballs, or clouds in your vertical-scrolling shoot-'em-up, or bit-bang in more parallax scrolling fields? Question No. 1: While it doesn't look like it will happen in hardware, do you plan to designate specific stretches of Dual Port and/or DDR2 as sound buffer? Or will programmers have to be doubly careful about reads and writes to prevent the use of sound data as general logic code, or the YM2149s from reading data meant for A.I. routines and spitting out garbage from the speakers. Question No. 2: Do you believe you have enough fabric RAM to stick a YM2151 on the Nexys A7-100T?
  14. Oh yeah! This means that you could recreate the waterfall effects of, say, the Sonic games, but make them work with (relatively) sharp A/V Multi-Out or VGA video output. @epsilon537, if you're reading this, would this addition compromise the geometry of the softcore of the BoxLamda too much?
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