Interest check: An updated MiniITX-MiniMig ( Pics!!! )

[amigadave]

tonyyeb wrote:
It is a good start for improvement of the minimig. However I would only be interested when write support is added to the code along with other improvements already suggested numerous times by other people.

Has anyone heard or read about write support working yet?  

I thought the same coder who was working on full ECS support and had completed some kind of NTSC 60Hz display work-around had implemented the write support, but then I have not heard or seen anything about it since.

Was it Yaqube, or something like that?

[yaqube]

Yes, I have completed write support and it seems to work pretty well (it's not perfect since standard ADF's are decoded MFM sector data, so only write to standard tracks is possible).

The ECS support is only partial. Only ECS blitter and PAL/NTSC switching is implemented. I had to remove programmable beam counters due to limited FPGA resources. They were consumed during improving compatibility. Maybe further code optimization would free some but at that time I was focused on getting more games to work.

Current implementation is not perfect and there are still things to fix. It will be done when I have more time.

All the project files have been sent to Dennis and he promissed to put it on his site after reviewing them. It was my agreement with him. I haven't heard any news from him for a few days and I guess he must be on his holidays. We must be patient.

[tonyyeb]

Patience is the key. At least some people are working on keeping the Amiga going.

Any news on hardfile support?

[Everblue]

I'm defenitely interested ! At a good price

[yaqube]

The hardfile support is next on my list.

But due to limited PIC resources (mainly RAM) expected transfer speed isn't high. Traversing through FAT on a disk seems to be a nightmare. That's why I've decided to switch to ARM microcontroller. Then it would be possible to add LFN and subfolder support (the FAT16 root directory is limited to 512 entries and you can have as many files there as long as all of them use 8.3 names - mixing lower and upper case letters or using some characters takes one LFN entry more). Also alphabetical sorting of files would be possible, currently they are displayed as their entries were created within root directory.

I have written small program (Windows) to sort alphabetically root directory entries on flash card and remove LFN's to make room for more files. Currently there is no point in using cards bigger then 512MB since you may have max 512 files (actually volume name takes one root entry so if you name your card you can have max 511 files) of 880KB each. It's good to format your card with maximum allowed cluster size of 32KB, access to files can be slightly faster. This program will be available soon after I do more tests.

I have designed an adapter board with ARM micro which can be plugged instead of existing PIC micro. The PCB is about to be manufactured. I consider it as the next step of Minimig evolution (all together with switching from SRAM to SDRAM, 16MB of SDRAM are cheaper and faster then 2MB of SRAM).

[tonyyeb]

Interesting stuff yaqube.

With these improvements you are making the Minimig more and more appealing. I hope they don't drive the cost up too much (for an already relatively expensive product).

[bloodline]

Certainly,  yaqube's improvements are making the MiniMig a far more attractive proposition!!!

I look forward to these!

[alexh]

yaqube wrote:
I consider it as the next step of Minimig evolution (all together with switching from SRAM to SDRAM, 16MB of SDRAM are cheaper and faster then 2MB of SRAM).

But are there enough I/O on the FPGA to support SDRAM? Can you get them the same form factor as the SRAM? Or are we talking a new PCB?

[bloodline]

alexh wrote:

yaqube wrote:
I consider it as the next step of Minimig evolution (all together with switching from SRAM to SDRAM, 16MB of SDRAM are cheaper and faster then 2MB of SRAM).

But are there enough I/O on the FPGA to support SDRAM? Or are we talking a new PCB?

Sounds like a new PCB to me... we are losing PIC for an ARM etc...

[tonyyeb]

alexh wrote:
Or are we talking a new PCB?

bloodline wrote:
Sounds like a new PCB to me... we are losing PIC for an ARM etc...

yaqube wrote:
I have designed an adapter board with ARM micro which can be plugged instead of existing PIC micro.

Not sure what to conclude  :-?

An adapter board maybe would mean existing Minimigs can use the updates?

[alexh]

Bloodline never reads posts properly, get used to it ;-)

ARM Micro seems overkill, especially if it needs own RAM and program Flash on the plugin board, I guess it is what you had to hand, which model is it?

[bloodline]

alexh wrote:
Bloodline never reads posts properly, get used to it ;-)

Oi! I resent that! :-P

ARM Micro seems overkill, especially if it needs own RAM and program Flash on the plugin board, I guess it is what you had to hand, which model is it?

I would assume the ARM board would be for development, and Retro upgrades... but if he wants to swap out the SRAM, then the existing board simply can't work?!? SRAM and SDRAM are electrically totally different :-)

[yaqube]

It would be possible to plug a PCB with ARM into the PIC socket on all existing Minimigs.

The SDRAM will require PCB change so it would be limited to new PCB designs like Illuwatar's one. Although I will try  to implement it on my Minimig using wires first. But this solution isn't feasible for others.

@alexh
The SDRAM pinout is different from current SRAM's so no drop-in replacement. The SDRAM's address bus is multiplexed so current number of memory IO pins should be ample.

[yaqube]

@alexh
It's an ATMEL AT91SAM7S256. http://www.atmel.com/dyn/products/Product_card.asp?part_id=3524

It has 256KB Flash ROM and 64KB RAM on chip. It's not an overkill, it's a simple and small MCU with ARM7TDMI core. No external parts exept a crystal and some passive elements. It has built-in USB device port and factory programmed boot loader so firmware upgrades are possiible through USB connection.

More over it's possible to create USB mass storage class support (or adapt existing one) for Minimig's SD-Card so you could write to it through USB (solution similar to the PSP). But this is the future.

[bloodline]

@alexh

:-P :lol:

[alexh]

yaqube wrote:
@alexh
It has 256KB Flash ROM and 64KB RAM on chip. It's not an overkill, it's a simple and small MCU with ARM7TDMI core.

Which is almost 3x the price of the device it is replacing. I wonder what that does to the overall retail price of MiniMig? (Which was already very high).

How much does it cost? [Edit: ~$11]
How much was the PIC? [Edit: ~$4]

But if you could reduce the cost equally by switching to SDRAM you might be able to bring it back in line.

@55MHz it would have considerably more power than MiniMig :-)