Issues and Notes

Compact Flash Card Format

The Compact Flash card needs to be formatted as either FAT16 or FAT32.

Compact Flash Card Voltages

Most Compact Flash cards operate at either 3.3V or 5V.

The Amiga will supply a nominal 5V but this can vary.

The CF card may try to operate at 3.3V if the 5V supply is too low.

Check your 5V supply going to the PCMCIA port. VCC is on pins 17 and 51 of CN15:

However, some some CF cards simply won't work with the Amiga's 5V signalling levels.

_CC_WE_PGM (pin 15) and _CC_OE (pin 9) signals measures 3.8V on non-working cards. On working cards they measure 5V.

Torsten Jager (author of compactflash.device) :

A1200 has no real PCCARD chip. Instead, there is a general purpose NMOS gate

array flashed for this task. With those "pull up" resistors, it emulates

old TTL

signal levels:

0V <= level_0 <= 2.4V; 4.5V <= level_1 <= 5V;

CF, on the other hand, uses (or emulates) CMOS standards:

0V <= level_0 <= 0.5*supply_voltage; 0.5*supply_voltage < level_1 <= supply_voltage;

All known CF cards work at 3.3V internally. The interesting thing is what the _interface_ part does. Many cards let it run at full supply_voltage. They will usually work. Some cards run it at their generated 3.3V as well, and fail on A1200. Thats it.

BTW#1: The 3.8V solarmon read are the result of the CF surge protection. No need to ring the alarm there, currents are low enough not to damage anything.

BTW#2: It may also depend on what A1200 revision you have. The Amiga Technologies reissue (that I have) is rumoured to be more compatible.

It is technically possible to build an adaptor that correctly translates the levels, and maybe supplies real 3.3V. However, all adaptors I have seen o far dont do that. They just contain 2 plugs and some wiring.

So the easiest way is probably to make a blacklist of non working cards.

Compact Flash Adapter

These are mostly passive and don't have any active components.

Memory Address Range Conflicts

The second Zorro-II 4MB 24-bit address range (600000-9FFFFF) was designed for use by either:

• PCMCIA Memory Cards

• Fast RAM

Note: The above is applicable for when a PCMCIA Memory Card is used, not a PCMCIA Compact Flash Card (as these are storage, not memory); or a PCMCIA Network Card.

Only one of these memory types can be used at a time.

A 24-bit 8MB memory expansion and accelerator card will allocate the second 4MB of its 8MB in this 600000-9FFFFF address range.

A 32-bit memory expansion or accelerator cards that allocated memory in the Zorro-III 32-bit address space, so does not cause any issues.

Kickstart 3.1 and 3.X will disable the PCMCIA slot when 8MB of 24-bit Zorro-II RAM is detected.

Kickstart 3.0 and lower does not do this check.

Kickstart 3.1.4 and does not do this check.

A patch is available for Kickstart 3.1 to patch card.resource to disable the memory checks:

http://eab.abime.net/showpost.php?p=1172678&postcount=226

http://boboo.szm.com//cardres.lha

Copy cardres.ld.strip to L: and add the following to the startup-sequence:

C:LoadModule >NIL: L:cardres.ld.strip REVERSE

Notes:

On an A1200 rev 2B with Kickstart 3.0, with an 8MB memory expansion card (in 8MB mode) that allocates it in the 24-bit Zorro-II range, and with ClassicWB LITE installed, there seems to be something that causes crashes and instability.

Booting in to a clean Workbench environment with just CFD and FAT95 drivers, the same hardware setup is working without any issues.c