ACA 1221EC/25 Turboboard

This accelerator comes with a 68ec020 (without MMU) processor (25MHz rating) and 16MBytes physical memory. 9MBytes of this physical memory can be used as fastmem, and up to 7 MBytes can be used as a ram disk. The CPU speed can be switched in four steps between 17.03MHz and 42.5MHz. Overclocking the card beyond 28.38MHz will require active cooling; operation at this high speed is not guaranteed.

ChipMem access speed has been greatly improved in comparison to the ACA1220, which will help eliminating the so-called "Turrican slowdowns" and other WHDload game hickups. Although the card is running asynchronously to the A1200, synchronous ChipMem speed can be achieved while maintaining full PCMCIA compatibility.

The ACA1221ec has much faster memory performance than most older designs with a 68020 processor. The modern 3.3V SD-Ram is clocked at over 85MHz, resulting in 0-waitstate access most of the times.

As with our previous ACA12xx accelerators, the ACA1221ec supports the popular 1MB Maprom option. Maprom allows you to increase ROM access speed by copying the Kickstart ROM into an especially-reserved memory space. This will improve real life performance considerably, but it will also enable you to load any higher version or patched version of a Kickstart ROM. The ACA1221ec is the first of our accelerators that supports MapROM at power-up: By setting a jumper, the Kickstart ROM is copied to the reserved space automatically, so you don't need to install any MapROM tool.

In addition to that, the ACA1221ec makes sure that the exec base in cacheable 32-bit fastmem. This is another "first" that we've introduced to the world of 68020/68030 accelerators for the A1200.

Another huge improvement over older accelerators is memory mapping to the legacy 0x00c0.0000 address. This is the location where many A500 games expect a trapdoor memory expansion. The ACA1221ec card gives a good compatibility boost only because of this little chunk of memory in the right place.

The ACA1221ec has two clock ports for expansions: The clock port is mainly meant for an RTC module, but it can also be used to connect any clockport device that has been designed for the A1200. It's a straight copy of the A1200 internal clockport: Very early A1200 board versions do not have a usable clockport, so this port will come in handy for owners of such a board. More details about possibilities and limitations of this port can be found in our technical Wiki.

The second clockport is specifically designed for the RapidRoad USB host controller: It is considerably faster than a normal A1200 clock port, which will result in considerably higher USB transfer rates. This means you will be able to install USB in an A1200 without opening the computer! This port can also be used with a Subway USB controller. Both physical expansion ports can only be used with an A1200 or the forthcoming ACA500plus. Clockports cannot be used on the ACA500.
Package contains:

• Accelerator with RAM and CPU assembled
• short installation manual

You will need in addition to that:

• transfer method for the ACAtune and ACAcontrol tools to your Amiga (free download from the Individual Computers wiki)
• motherboard patches as described by Commodore: A1200 capacitors E123C and E125C may need to be removed.

Processors on this card are used and may have scratches.