Minimig PCB run - interest thread

[alexh]

freqmax wrote:
alexh:
Why would not simultaneous floppy and harddisc (file) access work?

There is only one interface to the MMC through the PIC and they would have to share.

[alexh]

freqmax wrote:
One could implement a queue or semaphore that sends out one request to the MCU at a time. Floppy & Harddisc doesn't have to access the MMC simultaneously in the physical sense.

Of course.

Primarily it is dependant on: Data Rate.

Something that you cannot change (without altering the clocking, or the data bus width)

If you cannot get the data from the MMC fast enough to interleave floppy disk & hard disk accesses (not necessarily 1:1) and keep compatibility then you wont be able to do it. Maybe I am worrying over nothing...

Secondly it is dependant on how much room is left in the PIC and how much room / block RAM is left in the FPGA.

[alexh]

Belial6 wrote:
Of all the things people want for v1.2+, the one that I think would be the biggest benefit would be adding a USB port.

Probably time to end this now. There will never be a USB host for a 7MHz 68000 with 1.5Mbytes of RAM. The USB software stack is too demanding.

[alexh]

1NOM155 wrote:
even if USB 1.0???

Yes, even USB 1.0 or 2.0 Full Speed. The software memory and processing overhead is about the same for both.

[alexh]

Impossible, they must have a BGA rework station.

[alexh]

blachner wrote:
My personal wish list for a Minimig V2 would be:
- IDE Port

Why would you want an IDE port? I am almost certain we'll be able to emulate hard disk using the MMC card using existing MiniMig

[alexh]

little wrote:
At the present time I do not think somebody has written any of those cores

http://www.opencores.org/projects.cgi/web/t65/overview
Opensource 65C816 VHDL

[alexh]

@crumb
Plug it into your PC, copy the files to the SD card (or the HDF on the SD card). Just like you would for WinUAE etc.

I wonder what's next to be suggested?

Bluetooth I/O and sensor bar input for a Wiimote to allow "lightgun emulation" on LCD panels? :-)

[alexh]

freqmax wrote:
How much ROM does CDTV / CD32 use ..?

CDTV 256Kbytes
CD32 1Mbyte

[alexh]

AJCopland wrote:
Actually one possible reason for real IDE would be to have CDTV emulation once ECS is working.

CDTV is OCS ;-) (Well half OCS, it has a FATTER Agnus)

The CDTV doesnt use IDE :-(

It'd also be good for later v2.x MiniMigs with a 32bit bus and AGA so that the CD32 can be properly emulated.

1) Put ISO images on SD card?
2) Solve other v2.x problems (RAM, CPU, FPGA) first?

[alexh]

AndrewBell wrote:
Why use one computer when you can use two.

It's a one off operation. Not like you'd have to keep the PC connected all the time.

AndrewBell wrote:
Maybe you could work a Mac into the process too.

Last time I looked a Mac was a PC.

AndrewBell wrote:
I know, what is it with these people who want to make a new Amiga that supports modern hardware standards?

Exactly my point. Glad we agree.

[alexh]

freqmax wrote:
@alexh:
Guess it's useful to make the kickstart loader have 256kB granularity at minimum then.

Or do as is done at the moment, pad the file to 512kB. The CDTV uses a standard 256Kbyte A500 KS1.3.

It also has extra roms, sometimes called PROMS, sometimes called extended ROM's. These contain the CDTV menu system.

[alexh]

Are you going to release details about the modification to MiniMig core to use an SDRAM controller rather than SRAM?

Doesnt have to be "code", just in overview.

How does latency and burstiness affect things? Did you run the SDRAM at a multiple of the MiniMig core frequency?

Has anyone looked at PSRAM (Pseudo SRAM) as a viable alternative to minimig's SRAM? I think they are cheaper, larger, and would work just like SRAM. Perhaps a very "quick n dirty" alternative.

[alexh]

little wrote:
As a side note, can anyone tell me if it would be posible to make this external parallel port floppy drives read amiga formatted disks?

No. It probably would not be possible.

It depends on the capabilities of the floppy to parallel port chip inside. Most are very PC 1.44Mb orientated.

No-one has _ever_ been able to make one of these drives read Amiga disks when connected to a PC and hence the reason for Catweasel controllers.

It would not be suitable for DF0, connected to a minimig via it's parallel port.

A regular PC internal floppy disk (or a DELL external laptop disk) would be perfect though.

Traditionally you cannot use PC 1.44mb floppy drives on a real Amiga because the 2x rotational speed of these drives means the data is 2x bandwidth and the Paula chip(?) cannot cope. This limitation can be removed in MiniMig.

[alexh]

little wrote:

how about adding a selector header (like the one that selects 15/31 khz) to select if the minimig has an active internal floppy interface or an active external parallel port? Chances are people will not need both (or at least will not use both at the same time)

I think Parallel port and external floppy disk drive are the the same connector.

http://www.amiga-hardware.com/download_photos/a500_4_big.jpg

If you had a minimig with this connector (and an FPGA with enough I/O) All you need is a different MiniMig "image" on the SD card to switch between parallel port or real floppy disk.

[alexh]

You might be able to use the AGL250 and above.