C64 Building Block Computer (was: IEEE 488 bus)

christianlott1 wrote:
Of course you'll need to be able to configure it from a running
system. Configuring this profile can be done from whatever system is
set up to program it. I think jumpers are out of the question at most
levels ;)
Note that softswitches drive costs up.
Since programmable memory mapping and bus interfacing is central,
maybe it could be used to build old school arcade systems (a la MAME)
with real processor/video/audio chips.
Yes, if the design was very generic, like S-100, you could do anything. As such, I think you should open the design up to other vintage machines.
We discussed PCI-Express years ago...
Yeah, and it went about like the current "Maximum Safe IEC cable length..." thread.
IF it's a backplane system, can it support 16 bit configurations?
Not easily. I mean, you can put the extra data lines on the bus, but what do you do if you want an 8 bit device to talk to a 16 bit one? The 8 bit device needs to perform two reads, but it can;t get at the high 8 bits of the data from the lower data lines.
Just wondering if we're talking about a C64 board with a bunch of
sockets or a board for each chip.
More like a board for each IC. Otherwise, it can't be expanded. Maybe, since some things are required (6510, ROM) together, they can be on the same board.

An all-in-one C64 board may limit how it can be expanded? Maybe not
since the glue logic can be configured to reroute/exclude/include
chips from other boards?
It can, but that drives prices up.
ok. As long as this slow down is synchronus inside the whole system ie
not slowing down just the processor, slowing down the VIC2 as well.
Yeah, hate to be the wet blanket, but if you underclock the VIC, you get no picture.
If you were planning on doing a run, boot rom is most important, then
speed...
Ah, k. That's the easier item to add.
So it shows the pins of the real chips and the interface allows you to
wire things up in the glue logic? Perfect!
That was the idea.

You mentioned substituting newer VIAs for older. There are no
substitutes for the VIC and SID. Can another processor sub for the
6510?
A NMOS 6502 with a small CPLD to emulate address 0 and 1 would work. The CPLD could live on a board under in between the 6502 socket rails, making it a pin/compatible item.

But, I think the FPGA idea is better, because:

Fewer board types. All boards would have an FPGA and a loader flash. The bus would also be on there. Then, you have a couple variants:

o Memory board (socket for RAM or ROM or both)
o digital IO board. Header for a custom IO connector or 2 (or more)
o Analog IO board (places for a bit of R2R ladders and such.


You could buy a few boards and mash up a Z80 with a VIC, or Stella with a SID, or whatever. The glue logic would be embedded in the FPGAs, so no other chips are required. As a bonus, the FPGA designs, if they could be made modular, could then be synthesized into small 40 pin .6" boards to plug into a real 64. Thus, when the supply of real parts dwindles, there will be pin cmpatible replacements.

In this latter case, if you wanted to do a 16 bit or 32 bit computer, as long as there enough pins on the bus, it would be a cinch.

This idea, or something like it, would appear to have lots of potential audience (it's not even vintage computer related, as you could use it to make new machine building blocks or something along those lines)

Of course, the key is the tool to build the "machine".

Jim
.

Relevant Pages

  • Re: C64 Building Block Computer (was: IEEE 488 bus)
    ... Configuring this profile can be done from whatever system is ... super-PLA, FPGA, whatever, that routes all the lines. ... with real processor/video/audio chips. ... File it under - Communication to PC bus - topic. ...
    (comp.sys.cbm)
  • Re: Configure FPGA via PCIe
    ... low end would not adopt PCIe. ... than in embedded PC chips perhaps. ... One is if there are applications where the FPGA can't be used ... 1000 to 1500 pin device to select one of several different pre-canned ...
    (comp.arch.fpga)
  • Re: Configure FPGA via PCIe
    ... low end would not adopt PCIe. ... than in embedded PC chips perhaps. ... One is if there are applications where the FPGA can't be used ... 1000 to 1500 pin device to select one of several different pre-canned ...
    (comp.arch.fpga)
  • Re: Components Bin, Power Supply, & General Electronics
    ... So what about using a small FPGA to make a 'video/audio card' type ... are seperate devices for specialized tasks like video and audio ... what do you mean collision detection would be difficult? ... I've been looking around and considering switching to the SX chips ...
    (comp.arch.embedded)
  • Re: kablooey
    ... waveform generators failed, in the same VME crate, simultaneously. ... Two chips are running hot, ... and a big Xilinx SpartanXL FPGA. ... CPU bus, and it's supposed to be 5-volt tolerant on its I/Os. ...
    (sci.electronics.design)