Path: utzoo!utgpu!water!watmath!clyde!rutgers!cmcl2!nrl-cmf!ames!oliveb!sun!pepper!cmcmanis From: cmcmanis%pepper@Sun.COM (Chuck McManis) Newsgroups: comp.sys.amiga Subject: Re: A2000 PC-AT slots, and 'Fatso' Agnes Message-ID: <39214@sun.uucp> Date: 18 Jan 88 22:35:13 GMT References: <4230011@hpfclq.HP.COM> Sender: news@sun.uucp Reply-To: cmcmanis@sun.UUCP (Chuck McManis) Organization: Sun Microsystems, Mountain View Lines: 77 In article <4230011@hpfclq.HP.COM> cunniff@hpfclq.HP.COM (Ross Cunniff) writes: |>Question 1: With the advent of 16-bit (80286) bridge cards, it will soon |> become desirable to transform the last two PC slots on the |> A2000 into PC-AT slots. My question is: can the missing |> connectors just be soldered into place, or must some |> resistors/capacitors/etc. be added as well? This would not be too tough if you have a decent desoldering station. If you are using a sucker or solder wick be very careful not to lift a trace or two. As for capacitors etc, I didn't notice any conspicuously empty holes in the motherboard last time I looked that would hold them so my guess would be that they aren't needed. The below sounds like a mix up of facts so hopefully, this will clear the air somewhat. In any event the story will change after being passed from users group to users group. All of the things stated below, by me are things that I "know" to be true because either Commodore has verified them or I have played with them ... |>Question 2: I have heard rumors that C-A is developing a 'Fatso' |> Agnes that will: First let's get our terminology straight, 'Agnes' generates addresses and 'Denise' generates the display. (with some help of course). Commodore has admitted publicly that they are working on a version of Agnes that addresses 1Meg of chip RAM, and the 2000 and 500 mother boards both have jumpers to make the internal Meg of RAM continuous starting at 0. So I think it is safe to assume that at some time this will be the 'standard' configuration. |> 1. Allow for 400 line non-interlaced displays |> (on a multi-scan type monitor) At COMDEX Microway showed a gadget called "Flicker Fixer" that plugged into the Video slot of and Amiga 2000 (American version) and deinterlaced the video going out. They were mumbling $1000 for board (or was it board and monitor?). It looked really nice, they had a version of X-Cad running using 400 line screens. (Oh and it supports overscan screens so 704 X 448 is doable too). It should be at least orderable now, I don't know when they were planning on shipping it. The Amiga 1000 X 800 monitor is based on the same principle, except that it works on 500's and 1000's as well, yet is only monochrome. (it's *not* orderable now.) |> 2. Allow for more bitplanes (i.e. 7 or 8) |> than are currently possible. |> Now, the memory bandwidth for 320 pixel-wide screens |> exists to do both of the above (since 640 pixel-wide |> screens require twice the bandwidth, and *THEY* work). |> However, it is my understanding that 4 bitplane 640 |> pixel-wide screens take up ALL available memory bandwidth |> in chip memory. Any ideas how an Agnes/Denise/Paula |> replacement could create a 640x400x8 noninterlaced |> screen WITHOUT requiring a significantly faster |> bus and RAM chips? It seems to me that you would |> have to increase the clock rate to 14 Mhz, and drop |> in 120 or 100 ns RAM chips, in order to get the necessary |> bandwidth. Am I wrong? (I'm sure y'all will let me |> know :-> ). If not, I'll just have to dismiss these |> rumors as entirely bogus, as such changes would probably |> require MAJOR motherboard rework. This rumor crops up now and then, and you are correct that the bandwidth just isn't there to do more than 16 colors in 'High Resolution' mode. But even that is not as much of a problem as finding the chip real estate to put another 32, 96, or 224 color registers (for 6, 7, or 8 bits). I have worked on chip designs in the past, and registers take up lots of space. About the only thing you could do with a tweak would be to add bits to the DACs to increase the color palette. By adding a single bit to each color you could boost the range to 2^15 (or 32768) possible colors. If you added it to the HAM circuitry that would make subtle shading easier. So I think you are stuck with 32 colors for now. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you.