SuperCPU
                           General Specifications

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Processor
     The Western Design Center's 20 MHz W65C816S. The fastest version of
     this chip ever produced, it provides 8-bit 6502 emulation as well as an
     enhanced 16-bit Native operating mode. The W65C816S is capable of
     directly addressing up to 16 MB of memory, and has an enhanced
     instruction set which allows more powerful programming using fewer
     instructions. Despite the additional instructions, this processor
     remains fully backward-compatible with all legal 65xx family processor
     instructions.
CPLD
     An Altera Complex Programmable Logic Device provides the custom logic
     required to interface the new processor to your computer. CMD spent
     several hundred man-hours creating the custom programming for this chip
     that is vital in making the SuperCPU mimic the C-64's own internal
     logic.
RAM
     128K of Fast Static RAM gives the SuperCPU the ability to access
     program instructions and data at the full speed capability of the
     processor. Half of this fast RAM is used to replace the 64K of RAM that
     you normally have for programming in the Commodore 64. The other half
     is used as a form of Operating System ROM (OSROM). By reading the
     Operating System directly into RAM, the SuperCPU can deliver full speed
     when accessing routines that are normally ROM-based. If a ROM were used
     instead, memory 'wait-states' would be required which would decrease
     the efficiency of the accelerator.
ROM
     128K is supplied in the present SuperCPU 64. This ROM contains the
     Operating System overlays, which are downloaded into the OSRAM. The
     SuperCPU can accept up to 512K of ROM, however, and CMD is working on
     additional feaures that will use this additional capacity.
Pass-Thru Port
     A standard 44-pin Commodore Expansion/Cartridge Port is located at the
     rear of the SuperCPU. This port lets you plug in and use many of the
     cartridges and I/O devices available for Commodore computers.
Switches and Indicators
     Three toggle switches protrude from the top of the unit and provide a
     master Unit Enable/Disable, JiffyDOS Enable/Disable, and Speed Select
     (Normal/Turbo). Whenever the unit is operating in 20 MHz mode, the
     Turbo Indicator LED (top edge left of center) lights to indicate this A
     push-button Reset switch is also provided (top left edge).
Power Requirements
     The SuperCPU (without the RAM expansion option) draws approximately .4
     amps from your computer's power supply. Commodore 128 (and 128-D)
     computers provide ample power for this device. However, if you use your
     SuperCPU on a Commodore 64 or Commodore 64c, we highly recommend a
     heavy-duty power supply. CMD offers such a supply (5 VDC @ 3 Amps and 9
     VDC @ 1 Amp), Order Code: POWER64HD. WARNING: The current draw of the
     SuperCPU will very likely shorten the life expectancy of stock C-64
     power supplies.

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SuperCPU General Information

The SuperCPU is an accelerator module that plugs into the C64/128 Cartridge
port. At its heart is the W65C816S microprocessor running at 20 MHz, along
with 128K Bytes of high-speed Static RAM (the same type of high-speed cache
memory found in 486/Pentium systems), 128K Bytes of ROM, and a Complex
Programmable Logic Device IC (CPLD).

The SuperCPU is contained within an enclosure approx. 6-1/4" wide x 4" tall
x 2" deep. The enclosure has an opening for the Cartridge-Port Pass-Thru
connector at the rear, in line with the host computer's own Cartridge Port.
The main circuit board in the SuperCPU mounts vertically, so as to keep the
depth of the unit to a minimum. This helps to prevent devices plugged into
the pass-through port on the CPU from extending too far back from the
computer. Three easy-to-use toggle switches line the upper front edge of the
unit: A Unit Enable/Disable switch; a JiffyDOS Enable/Disable switch; and a
speed selection switch. A push-button Reset switch and Turbo mode indicator
LED are also provided.

Installing the SuperCPU 64 is simple: just plug it into the Cartridge port.
No wiring or jumpers need to be installed inside of the computer, and
there's no manual 'fine-tuning' adjustments to be made. (Note: The SuperCPU
128 will require mounting an internal 'daughter-board' in your computer).

Operating the SuperCPU requires no special knowledge. The user can perform
all computer tasks in exactly the same manner as with a stock system, while
gaining the benefits of accelerated speed. The toggle switches on the unit
are clearly labeled, easily accessible, and can be used without having to
refer to a manual in order to determine their function.

The SuperCPU 64 operates with C-64 and C-64c computers as well as the
C-128/128-D in 64 mode. The W65C816S processor supports all legal
65xx-family processor opcodes, providing a very high level of compatibility
with existing software -- including GEOS. The C-64 memory map is emulated
exactly, and proprietary write-thru logic ensures full compatibility with
all VIC graphic modes and memory mapping.

To help achieve a high level of performance, all operating system routines
are downloaded into the high-speed Static RAM upon power-up, eliminating the
bottleneck caused by ROM-based operating system code (on PC's, this
technique is called ROM-BIOS shadowing). 64K of high-speed SRAM remains free
for programs -- just like in a standard C-64. In addition, buffered
write-thru circuitry (similar to PC cache-controllers) helps the SuperCPU
avoid slow downs when writing data back into the C-64's RAM.

Additional Features

JiffyDOS: The JiffyDOS Kernal ROM for the computer is built into the
SuperCPU, providing DOS-Wedge commands and enabling high-speed serial
transfer rates to and from JiffyDOS-equipped disk drives. A JiffyDOS disable
switch is provided so that the SuperCPU can load programs which are not
compatible with JiffyDOS. This switch can be used to enable or disable
JiffyDOS while the CPU is running, and does not affect the operating speed.

Pass-Thru Port: The SuperCPU includes a Cartridge Port Pass-Thru connector
which enables the full use of most plug-in hardware devices such as
Commodore REU's, RAMLink, Swiftlink, SID Cartridge, and GEORAM. These
devices will work with the CPU running at 20 MHz and will not require a
slowdown to 1MHz. Most ROM cartridges (generally games) will either force
the SuperCPU to 1 MHz mode, or require that you manually switch off Turbo.

REU Compatibility: The CPLD chip in the SuperCPU includes special DMA
transfer logic to provide 100% compatibilty with all types of data transfers
to and from Commodore REU's. The SuperCPU does not have to slow down to 1
MHz in order to perform DMA transfers to and/or from the REU.

RAMLink Compatibility: The SuperCPU is 100% compatible with RAMLink, and
contains its own version of RLDOS, which will run from the SuperCPU's
high-speed static RAM. The faster RLDOS, along with the efficiency of new
65C816 opcodes will enable the SuperCPU to transfer data to and from all of
the memory on RAMLink's RAMCard at speeds which rival the DMA transfer rate
of Commodore REU's. Transfer rates to and from CMD HD-Series hard drives
connected to RAMLink's parallel port will also be significantly faster.

GEOS: Special features include the necessary Configure and driver software
to optimize GEOS for operation with the SuperCPU. In addition, an
intelligent write-thru hardware circuit designed especially for GEOS
effectively eliminates a major performance bottleneck associated with
earlier accelerator designs such as the Turbomaster and Flash-8. This design
feature, coupled with the 20 MHz clock speed of the WDC65C816S boosts the
performance of GEOS far beyond anything currently possible or imaginable.

Expansion Capability: The SuperCPU is equipped with an internal connector
which is to be used for the C-128 option board and for an optional RAM
Expansion card (available in late '96). Each of these cards will have
on-board SIMM sockets and can contain from 1 to 16 Megabytes of Dynamic RAM
(DRAM). The RAM on this card can be used as additional programming space for
advanced applications software.

Speed Selection: The speed selection switch provides on-the-fly switching
between 1 MHz mode and 20 MHz (Turbo) mode. The 1 MHz option can be used for
compatibility with programs (such as some games and cartridges) that may
operate too quickly in the Turbo mode. Speed can also be altered via
software using a simple POKE command, provided the unit is in Turbo mode.
(Note: The SuperCPU performs disk access functions properly in any speed
mode.)

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Copyright © 1996 by Creative Micro Designs, Inc.