Super64/20 Prototype

Processor 
       Western Design Center 20 MHz W65C816S (located near the upper left corner). 
CPLD 
       Altera Complex Programmable Logic Device (located near the lower left corner), which controls the various signals
       that interface the new processor to your computer. 
RAM 
       128K of Fast Static RAM (the four long chips located at top right/center). The three chips to the left of the RAM are
       used to control special memory mapping functions. 
ROM 
       64K (located in upper right corner). This contains the operating system, which is downloaded into part of the RAM.
       Running the OS from RAM provides faster operation for system calls. 
Pass-Through Port 
       Standard 44-pin Commodore Expansion/Cartridge Port (located bottom right/center). This lets you plug in and use
       many of the cartridges and I/O devices available for Commodore computers. 
Rocket Socket 
       Not actually a socket, but a header (located along the left side). This connector provides high-speed expandability for
       future options. 
Switches 
       The three switches (located along the top edge) provide a master Enable/Disable, JiffyDOS Enable/Disable, and Speed
       Select (1 MHz/Full Speed/Program Controlled). 
Miscellaneous 
       To the right of the processor is the clock oscillator, and just above the Pass-Through Port you'll see some additional
       glue-logic. 



SuperCPU 64/20 Preliminary Information


The SuperCPU 64/20 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), 64K Bytes of ROM, and a Complex Programmable Logic Device IC (CPLD).     The SuperCPU is contained within an enclosure approx. 6" wide x 3" tall x 2" deep. The enclosure has an opening for the  Cartridge-Port Pass-Thru connector at the rear, exactly in line with the computer's Cartridge Port. The unit is the same width  as a RAMLink, and when plugged in between the computer and RAMLink it aligns almost exactly with the RAMLink case.  The main circuit board in the SuperCPU mounts vertically, so as to keep the depth of the unit to a minimum. This prevents  devices plugged into the pass-thru 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.

Installing the SuperCPU is simple: just plug it into the Cartridge port. No wiring or jumpers need to be installed inside of the  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, and still gain the benefit of the greatly 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. As with  CMD's RAMLink, the SuperCPU has been designed to work out-of-the-box with any C64 or 128 computer -- no manual
"tuning" adjustments required.

The SuperCPU 64/20 operates with C-64 and C-64c computers as well as the C-128/128-D in 64 mode. The 65C816S  processor supports all legal 6502/6510/8500/8502 opcodes, providing a very high level of compatibility with existing software  -- including GEOS. The C-64 memory map is emulated exactly by the CPLD, and proprietary write-thru logic in this chip  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 64K of 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 having to slow down 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, GEORAM, as well as some ROM-based  cartridges. These devices will work with the CPU running at 20 MHz and will not require a slowdown to 1MHz.

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 be slowed down to 1 MHz in  order to initiate a DMA transfer to/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 65C816 will boost the performance of GEOS far beyond anything currently  possible or imaginable. 

Expansion Capability: The SuperCPU includes a connector (called the "Rocket Socket") which will enable the user to plug  in a CMD-supplied RAM Expansion card (available seperately). This card 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 either data or program storage. In  addition, some or all of this RAM can be configured for use as an ultra-high-speed RAM disk drive.

Speed Selection: The speed selection switch provides three options: 1) 1 MHz mode for compatibility with programs (such  as some games) that may operate too quickly in the turbo mode; 2) a "soft" Turbo mode which operates at 20 MHz and  provides programs with a software speed selection register for switching to a slower speed when necessary; and 3) a "forced"  Turbo mode which keeps the CPU in 20 MHz mode regardless of the setting of the software register. This mode is useful for  providing compatibility with existing programs that unintentionally alter the software register. (Note: The SuperCPU performs  disk access functions properly in all three speed modes.) The user can change speed modes by toggling the speed selection  switch while the SuperCPU is operating.

Development Support: CMD is actively seeking developers willing to create new commercial software and/or modify  existing software to take full advantage of the SuperCPU. A comprehensive package will be avialable which will include an  assembler which supports all 65C816S opcodes and addressing modes as well as documentation providing pertinent technical  specifications and guidelines. This package will enable developers to produce programs which take advantage of the  65C816S's enhanced instruction set, 16MB addressing capability, and additional RAM available on the SuperCPU's optional  RAM Expansion Card.

128-Mode Compatible Version? CMD has recently announced that a C-128/128-D version of the SuperCPU will be  made. This version will offer all the capabilities of the 64 version, but will include additional hardware to allow it to operate in
128 mode.



The SuperCPU 64/20 is slated for release in April of 1996, and the 128 version is expected to release approximately 90 days  later. An estimated retail price of approximately $199 has been announced for the SuperCPU 64/20. The retail price of the 128  version has not yet been announced, but CMD is making every effort to keep the price below $300. These prices are, however,  subject to change prior to release. Advanced orders with a $50 deposit are being accepted now for the SuperCPU 64/20,  and will guarantee delivery from the first production run at a price no higher than the announced estimated price. Contact CMD  Sales at 1-800-638-3263 to place your order. Advanced orders for the 128 version will not be accepted until CMD has firm  price and design information on this version.