Pseudo-disk *almost* ready for the big time.

["Alex Freed" <alexf@mirrow.com>]

"Later Days Apples Pseudo-disk" proudly presented by (previously unheared
of) Bronze Age Computing.


A while ago I wrote about my experimental MMC/SD interface that could look
to Apple 2 either as a ProDOS
storage device or as a DISK ][.

Took a while to iron out some glitches. Not sure all of them are gone, but I
feel the device is stable enough to
be presented to the world.

See http://mirrow.com/FPGApple/pseudodisk.html for details. Yes, the page is
rather primitive.
I swear my Verilog is better than my HTML :)

In a nutshell the board can act as a ProDOS disk or a DOS 3.3 disk. Or DOS
3.2 if you load such a nibble image.
I didn't run too many tests, but all the .nib files I tried seem to work.

Of course it works much faster in ProDOS mode. Takes about 2 seconds from
cold start to a BASIC program loaded
under ProDOS. By contrast the DOS 3.3 image takes 9 seconds to load DOS and
Integer BASIC from a .nib image.

It can be made a bit faster with some modifications to the firmware (Atmel
AVR program written in "C").

Of the 3 chips on the board (not counting the 3.3V regulator) all 3 are
programmable: the CPLD, the 6502 driver and the
AVR code.

Last time a few people expressed interrest in the design. Now is the time to
decide if pseudo-disk is to become a product.
I made 6 prototype boards. I'm keeping 3 for my 3 Apples: (2+, 2e and GS).
The other 3 are available.
If they are claimed and there are at least a few more pre-orders I'll make a
small "production" run. The 3 current boards do not have a solder mask, but
they have extra prototyping space for mods.
Imagine what they will be worth on ebay in 30 years :))

The MSRP is $100 per board. Another $15 buys you (at cost) an SD card with a
few pre-loaded images.


-- 
-Alex.