Floppy emulator

[tnt23]

Yesterday I've put the device into A500's drive bay and set it to DF0. Workbench 1.2, 1.3 and utilities like DOpus, AMOS Pro boot just great!

Bad news is that of six or seven games on my MMC only ARKANOID managed to load and run. Also, only two demos loaded and run OK, one is some 40K intro and ANNOUNCE.

Maybe this is due to the fact that AmigaDOS doesn't use INDEX pulse (says DiskMonTools manual), which is not implemented in my design, but can well be used by other software to sync to.

Hyperspeed wrote:
Avoid Spaceballs - State of the Art, I remember that demo turning my floppy drive into a buzzsaw!

:-D

State of the Art didn't run either. If I do a diskcopy from emulated DF1 to real floppy it runs just fine. There must be something important I miss about the floppy interface.

Looks great, I think it should be for DF0: internal and it would need to work well with the desktop casing (the eject button could be replaced with an access light).

Just out of curio, what is the maximum transfer rate of the floppy interface? The drives only do 10k/s and the flash cards 1MB/s!



EDIT: Oh, the F.Disk LED will be the access light right? We'll have to use putty for the eject button hole. ;-)

There is an LCD with all sorts of indications, like head movement, drive selection, side and dir signals :-)

Floppy speed test shows values around 21K-22K bytes per second. I don't know if the floppy DMA can be faster than 500K bits per second, or roughly 60Kbytes/s. We are trying to mimic the FDD as much as possible, so don't expect any breakthrough here :-)

[tnt23]

Zac67 wrote:

I think you should keep the 'use this device as a card reader, too' in mind while making changes to the hardware. It'd be a very good chance to attach the emulator in such a way that it can be used to access the flash card in a more efficient way (faster and higher capacity access).
Maybe through serial (probably slow), parallel (lot of hardware involved) or through the floppy port, just with a more efficient protocol - after all, you don't really need MFM for transport.
If you provide the means of accessing the flash card for real, someone else will probably write a driver for it, so it could be used as a hard drive replacement. It could even auto boot, just emulate booting a workbench disk with the drivers, mount the card and go on from there. How does that sound?

Sounds reasonable. I was thinking of a similar approach looking at A500 non-booting IDE interface where there needs to be a system boot floppy allowing for later mounting IDE drive(s). Will keep that in mind, thanks.

Another thing I'd like to implement is multiple floppy images handling. The amount of memory emulator has now allows for at least 2 floppies to be stored and switched between. Imagine 1st image is Workbench disk (probably autoloaded from MMC card BOOT directory) and 2nd is some game or utility disk, and you can swap them in an instant.

[tnt23]

timofonic wrote:
What about megring with 1541-III? I think meging your design with that and using a modular design like I said you before could make this device a lot interesting for more people (more  retroplatforms supported = more people interested). What about releasing the technical stuff with some Creative Commons license for non-commercial use? It could be nice having the stuff you did in self-mounting manner and technical stuff too for hardware geeks and the mounted stuff for the average people

http://commodore-gg.hobby.nl/feb18.htm

What about supporting other formats like DMS (compressed ADF) and IPF? It could be nice if not needing to convert between formats and only copying to the SD/MMC.

Don't know much about 1543-III, will look up the link. I am really uncertain which shape the emulator should take eventually. Making things as universal as possible can be evil sometimes :-)

For IPF format, the problem is that it is not documented, only available as compiled binaries (libraries) and that is not suitable to implement IPF support in this design.

DMS format can be an option, although I believe a desktop (Amiga or PC, or MAC) can be used to convert stuff between DMS and ADF.

[tnt23]

Hey ho!

I have fixed that games/demos loading (or rather not loading) problem which turned out to be me not following common floppy timing guidelines. So now I am watching excellent :banana: ARTE! :banana: demo loaded from emulated df0!

[tnt23]

@Mikkel

Can't tell. Definitely not before I solder a couple of boards for fellow Amiga users to test and see wether thing is a success.

[tnt23]

Not much news here. While waiting for another couple of PCBs to be done, I am fixing this and that. I had to rework original design a bit to implement INDEX support, as a number of games (namely Cannon Fodder) would not load properly without sensing INDEX pulse.

Different type of LCD, either character 4x20 or graphics 128x32, will probably be used in another design of emulator, along with universal SD/MMC connector.

[tnt23]

5char wrote:
Go for the big lcd, that would be hitech!

but with that index pulse problem fixed everthing seems to go as planed? My hope is that the floppy emulator will turn in to a product, so i can buy one

/M

Touchscreen would be more dramatic  :lol:

Yes, I'd say the emulator is more or less done. Time to go for feature freezing and feed it into production  :-)

[tnt23]

I'm fine, still waiting to pick up PCBs. Haven't got much time to work on the new (faster) design.

[tnt23]

Use Private Messages to reach me.

As for 1.44M media - no, the device only emulates DD floppies, that is 720K or 880K. What do you mean by '44 Ms are still 144 M?'  :-o

[tnt23]

Jeff,

Cool stuff. I guess you just upload track or two to SRAM and then shift the data out clocking from the PC? Neat!

[tnt23]

Unfortunately, no updates on the project so far.

That's because I've been busy releasing an even more exciting project - my second baby was born on April, 10, and it's a boy! :-D

I guess I'll get back to floppy emulator quite soon.

[tnt23]

@Mikkel

That's the only design that doesn't need neither schematics nor special equipment for building. Everyone can DIY this :-)

[tnt23]

AnamigaKid wrote:
Why not just use the Amiga RAM disk or RAD to unpack DMS or ADF too.....

Sounds far too complicated if I only want to watch a few demos on my unexpanded A500  :-o

[tnt23]

No updates yet, sorry.

Probably will revive the project right after the Chaos Constructions 2006 party taking place in St.Petersburg, Russia this August, where the emulator will be shown.

[tnt23]

Umm, I really have no idea now.

[tnt23]

Still no news here Another project still keeps me busy.

Good thing is, that project is based on a similar chip, and this makes me believe it won't be too hard to switch back to my floppy emulator.