Hardware assisted PC emulation

[ElPolloDiabl]

   With the early PC emulator boards they could take advantage of the Amiga chipset and expansion ports.
   Is it possible to make a modern one? Would it be a big speed increase over PC-task?
   Also what would be involved in making an ARM emulator board?

[giZmo350]

Hmmm, weird, I was just thinking of this yesterday... Actually I was wondering if there was a way to activate the PC slots without a bridgeboard but, the more I thought about it, the more I realized it wouldn't be real useful without a CPU. Anyways, the reason I was thinking the same thing is that I have an old 16bit (complete and like new) MPEG decompression board that would be cool to utilize. Minimum requirements are fairly modest; 386/win3.1/2MB/DOS5 etc. It came with all the software to playback VCD's @ 24bit/MPEG-1 video and MPEG-1&2 audio using a simple passthru cable.  I'm building up my A2000 to be a King Kong multimedia machine w/toaster functionality (WIP). Anyone brought up adapting a Pi to ZII/III? Good post ElPolloDiabl!

[Methanoid]

Hmmm, weird, I was just thinking of this yesterday... Actually I was wondering if there was a way to "activate" the PC slots without a bridgeboard but, the more I thought about it, the more I realized it wouldn't be real useful without a CPU. Anyways, the reason I was thinking the same thing is that I have an old 16bit (complete and like new) MPEG decompression board that would be cool to utilize. Minimum requirements are fairly modest; 386/win3.1/2MB/DOS5 etc. It came with all the software to playback VCD's @ 24bit/MPEG-1 video and MPEG-1&2 audio using a simple passthru cable.  I'm building up my A2000 to be a King Kong multimedia machine w/toaster functionality (WIP). Anyone brought up adapting a Pi to ZII/III? Good post ElPolloDiabl!

Over at Atari-Forum.com a user Jookie has built a device (Cosmos Ex) that interfaces a Raspberry Pi with the ST. The Pi acts as a HDD interface, network interface and FDD emulator. It will decompress ZIP images etc for you to.

Now.. an Amiga version of this could be an interesting idea...

[danbeaver]

   With the early PC emulator boards they could take advantage of the Amiga chipset and expansion ports.
   Is it possible to make a modern one? Would it be a big speed increase over PC-task?
   Also what would be involved in making an ARM emulator board?

What would it do?  Run MD DOS 6.22?  Windows 3.1?  Linux? It seems the cost and effort would be best utilized on a proven SBC with new software like the Janus to allow the Amiga to access it?

[ElPolloDiabl]

94 was when we lost a lot of software to PC. It would give me some satisfaction having an Amiga running 90s PC software.
Running DOS is a good hobby too.

[danbeaver]

So it makes no sense to use more up to date hardware supported by classic Amiga software?  Interesting. But why use an ARM to run Intel/AMD DOS?

[Fransexy_]

how feasible would be to replicate the old bridgeboards with modern cpus so that old janus works? a board with a i3/i5/i7 socket a ram slot and fpga emulating all other chips present in the bridgeboards (maybe problems with voltages and power?). why you ask? and why not?

[Oldsmobile_Mike]

how feasible would be to replicate the old bridgeboards with modern cpus so that old janus works? a board with a i3/i5/i7 socket a ram slot and fpga emulating all other chips present in the bridgeboards (maybe problems with voltages and power?). why you ask? and why not?

Modern CPU is going to have all kinds of power requirements that an old Amiga PSU couldn't cope with.  Does Janus even support anything beyond 386/486?  Anything's feasible with enough $$$$.  One of these days I'm going to stick a Raspberry Pi in an Amiga 2000 case, not sure if I'll have room though???  :lol:

[Fransexy_]

Modern CPU is going to have all kinds of power requirements that an old Amiga PSU couldn't cope with.  Does Janus even support anything beyond 386/486?  Anything's feasible with enough $$$$.  One of these days I'm going to stick a Raspberry Pi in an Amiga 2000 case, not sure if I'll have room though???  :lol:

I think that a lot of people have an adapted powerfull PC psu already on their miggys. Also couldbe used the low power Atoms instead XD

[giZmo350]

So it makes no sense to use more up todate hardware supported by classic Amiga software.  Interesting. But why use an ARM to run Intel/AMD DOS?

Why is a tree good? Why is the sunset good? Why are boobs good? :laugh1:



Anyways, be nice to see a cheap, new hardware solution to bridging DOS to Amiga and use some 16bit boards. I have a ton of DOS software and games that I still use. Is this thread just gonna go nowhere now?

[danbeaver]

Finally speaking of the address and data buses, how do you connect a Bridgeboard up to a modern processor?  As stated before, if the consumer wants to run this type of hardware/software on a more modern CPU, why would reinventing the hardware be easier than writing an update of the software?

True there are issues with opening up a window in the Z2 (original) memory space to transfer information (keyboard, mouse, files) between the two that may require a BIOS firmware update (still software) and a software port, but laying out a new CPU board, or trying to put a Pentium or greater level CPU on an existing board?  Really?  Good luck on the prototype, wire wrapping can be fun!

[giZmo350]

Well, for practical purposes, and I'm not sure ElPolloDiabl was actually suggesting anything more than a 486, IMO, a low cost 486 in FPGA w/ZII/ZIII bus, that could take advantage of existing software would be great! Add a $hit load of ram maybe. I'm not an expert on what all something like that would have to emulate though... or how difficult that would be. Do you think it is do-able though?

[danbeaver]

There is a 486 conversion for the 386SX chip that is (was) available; see http://www.ebay.com/itm/SEALED-CPU-Vintage-NOS-Cyrix-386-to-486-Clock-Doubled-Upgrade-Kit-GOLD-CPU-/291449076968?pt=LH_DefaultDomain_0&hash=item43dbb7fce8

And a GoldenGate was made too.

This can turn a Commodore 386 Bridgeboard (SX chip) into a 486 to run those DOS based programs really faster than before...

[giZmo350]

There is a 486 conversion for the 386SX chip that is (was) available; see http://www.ebay.com/itm/SEALED-CPU-Vintage-NOS-Cyrix-386-to-486-Clock-Doubled-Upgrade-Kit-GOLD-CPU-/291449076968?pt=LH_DefaultDomain_0&hash=item43dbb7fce8

And a GoldenGate was made too.

This can turn a Commodore 386 Bridgeboard (SX chip) into a 486 to run those DOS based programs really faster than before...

 Yea, I've seen a few bridgeboards around and always tempted to pick one up, to perform the mods, but the cost always goes crazy on ebay and they hardly ever show up anymore. Exactly how does the bridgeboard activate the PC slots anyway?

[danbeaver]

The PC slots are just a passive backplane in 8-bit (XT-mode) or 16-bit (AT-mode) and they communicate with the PC cards the same as a PC or a SBC (Single Board Computer) at a pretty crappy 4.77 MHz (XT) rate or 6 to 8 MHz (AT).  Since they are passive electrical connections, the bus speed is set by the CPU board.  If you recall, the EISA was an ignored attempt to go 32-bit, and IBM's own microchannel was a failed (proprietary) 32-bit attempt before the AGP and PCI came into play.