The Deep Thought 42 single board computer from Semidisk Systems
is the best CP/M-compatible computer ever designed. This may
sound like just another grandiose advertising claim, but look at
these features:
Hardware
The DT42 is a single board computer, sized 5.75" by 8", and uses
only +5V at 1 amp with a complete complement of chips.
- 9.216 MHz Hitachi HD64180 cpu gives you computational
throughput beyond that of a 12 MHz Z80 machine. And, unlike some
other 9MHz 64180 designs on the market, this machine has no RAM
wait states to slow you down (one RAM wait state slows most other
designs by 30%). 12.288 MHz will also be supported when faster
64180 chips are available - this is better than a 16MHz Z80!
- The board comes with a floppy drive interface design that
supports 4 5.25" 48tpi or 96tpi AND 4 8" single or double sided
floppy disk drives simultaneously. Eight floppies at once!
Additionally, the 1.2Mb 5.25" floppy drive models (such as those
used in the PC-AT) are also supported.
- 512Kb RAM is standard, with 428k available as RAMdisk. An
optional disk emulator expansion card adds 8Mb of ultra-fast
storage, with optional battery back-up. The awesome processing
speed of the DT42 combined with this large amount of RAMdisk will
make you wonder what all the fuss regarding hard disks is about!
- If you want a hard disk, the DT42 supports this also. An
included on-board SASI port interfaces directly to popular hard
disk controllers made by Adaptec and Xebec to give you megabytes
of hard disk storage.
- Communications facilities include 4 on-board serial ports
and a parallel output port. Two of the serial ports can
accommodate speeds in excess of 300k bps; and the DT42 overcomes
a shortcoming of 9MHz 64180 designs and allows you to run serial
ports at 38,400 baud. One of the serial ports connects to an
optional on-board video display manager and keyboard controller,
so no separate RS-232 terminal is required (although one can be
used if desired with no software changes).
- Optional Dallas Semiconductor "Smartwatch" real time
clock/calendar chip, and additional EPROM sockets are available.
Software
- A special version of the advanced Z-System disk operating
system is available with the DT42. This includes ZCPR 3.3 and
ZRDOS 2.0 and over 90 utility programs. This version of Z-System
(called the "Hyperspace Z-System") places ZRDOS outside of the
64k TPA space. Z-System is modern software technology, packs an
incredible amount of power and features, and will give you
tremendous flexibility and convenience compared to CP/M or MSDOS.
- The BIOS of the DT42 supports the large amounts of
RAMdisk, hard disk, and floppy drives available. Communications
channels are interrupt-driven; CP/M-compatible logical devices
such as LST: and CON: are easily redirected; and the majority of
the BIOS resides outside of the 64k TPA space.
- Because of the advanced characteristics of the Hyperspace
Z-System and the BIOS, CP/M-compatible application programs see
57.5k bytes free memory, even with a full featured (5k overhead)
ZCPR3 implementation including IOP and RCP support.
- Very powerful BIOS-resident disk handling software
supports eight different floppy disk formats without any special
conversion software. You can directly read, write, and copy
between formats such as Kaypro, Osborne, 8" single density, etc.
- Utility programs written for the DT42 include FVC, CONFIG,
and HDFORMAT. FVC allows you to format, verify, and track-to-
track copy the different floppy disk formats; CONFIG allows you
to customize elements of the system software such as reassigning
logical disks (eg, any physical device such as the RAMdisk could
be set as drive A:, drive B:, etc.), setting communications ports
parameters like baud rate etc.; HDFORMAT is a very flexible
SASI/SCSI command editor that allows you to communicate with a
SASI/SCSI device attached to the DT42.
- The EPROM-resident DT42 Monitor allows you to examine and
modify memory within the full 512k; auto-boots the Z-System (if
available) when the hardware is reset; and contains important
debugging-style commands for setting breakpoints, tracing program
execution, and uploading code. You can switch between the
Monitor and Z-System at any time.
No other computer ever made possesses the raw power and features
of the DT42. This machine is blindingly fast, and the Hyperspace
Z-System represents a significant and positive new development in
CP/M-compatible computing. Combined with standard CP/M-
compatible applications such as the forthcoming WordStar 4.0 or
dBase II, Multiplan, Turbo Pascal, Turbo Modula-2, etc., this
machine will provide for your computing needs for years to come.
To find out more about the DT42, please call or write SemiDisk:
SemiDisk Systems, Inc.
11080 SW Allen Blvd.
Beaverton, Oregon 97005 USA
(503) 626-3104
