GUBBINS@RADC-TOPS20.ARPA (Gern) (11/24/87)
Zenith H/Z-100 Upgrade Series Part 1 23-NOV-87
INFO-HZ100 Gern
Introduction:
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Zenith Data Systems unveiled the H/Z-100 Professional Desktop Computer
Series on 7-JUN-82 at the National Computer Conference in Houston, Texas.
The H/Z-110 and H/Z-120 was the first combined effort of ZDS and Heath
Company. (Heath was bought by Zenith Radio Corporation in December 1979).
The Z-100 series was designed to be an exceptional system, with the
computing power, flexibility, and expansion capabilities to meet the needs
of the time and far into the future. The Z-110 is a low-profile unit with
a separate monitor and the Z-120 is an all-in-one with a built-in
monochrome monitor. The ET-100 is an educational 16-bit computer trainer
(and is still in production) which is a close cousin of the Z-100 (full
16-bit hardware and software compatibility, but lacking the 8085 and S-100
Bus). Zenith supplied the 'wired' units and Heath sold the H-100 kit
versions.
The Z-100 series uses both the Intel 8085 and Intel 8088 CPUs (originally
both at 5.0 MHz, later models and upgrades operated the 8088 at 8.0 MHz).
It has a 5 slot IEEE-696 S-100 Expansion Bus making the Z-100 very flexible
and expandable. The S-100 Bus and Intel 8088 created the doorway into the
future with new and sophisticated 16-bit software and an IEEE industry
standard bus. The Intel 8085 provided a bridge from the extensive base of
8-bit HDOS and CP/M software.
The Z-100 came with a minimum of 128K RAM, 192K RAM standard on the
motherboard with later model ('new motherboard') machines and upgrades
supporting up to 768K RAM on the motherboard (plus the use of 256K or more
additional RAM Drive on the S-100 Bus). The S-100 bus supports up to 16
other Bus Masters (CPUs/DMA/TMA) in the system and the direct addressing of
up to 16MByte RAM.
The video capabilities of the Z-100 remain versatile. The 32K RAM
monochrome video memory is expandable to 192K RAM (standard) yielding 8
colors per pixel in a high resolution interlaced graphics mode of 640 by
525. This resolution was too high for the reasonably priced monitors of
the time ($1K or less), so the normal video supported was 2 pages of
640x225 in 8 colors non-interlaced. Other high resolutions are possible
with the software configurable standard video board. Third party options
are now available to further enhance the high capabilities of the Z-100
video (16 and 64 colors/pixel, 640x480 non-interlaced with multiple sync
monitors, etc...). 640x480 resolution is desirable to yield 'square'
pixels on the industry standard 3:4 aspect ratio CRT and the standard Z-100
has easily supported this mode with the ZVM-136 Long-persistence Color
Monitor from the start. The standard Z-100's superb high resolution color
graphics remained far superior to all other machines of the class for a
very long time.
The S-100 Floppy Disk Controller supports four 5.25 inch 48TPI or 96TPI
single or double sized disk drives and four 8 inch single or double sized
disk drives. The current 1.2MByte 5.25 inch High Density disk drives as
used on the IBM-AT are really 5.25 inch versions of an 8 inch disk drive
(electrically and timing compatible). This allows the direct connection
of the 1.2MByte disk drives to the Z-100 (8 inch connector) with no
hardware or software modifications (Note: The IBM-AT 1.2MByte disk format
is different than standard 8 inch format, so a software patch is needed to
read/write AT format 1.2MByte disks).
The S-100 Winchester Controller and Data Separator supports up to 2 hard
disks of almost ANY type up to 65MBytes each. The Z-100 Winchester
Controller was designed before the Western Digital Winchester Controller
chip set was available. The Z-100 controller is a VERY high speed
bit-slice processor (many times faster than the hard disk controllers
currently in use on other microcomputer systems). All data transfers are
made by TMA (DMA in this case), programmable as burst or byte modes of
operation.
The Z-100 is a technically well known machine not because of the complete
technical and software manuals, but mostly due to the attitude of
information sharing that has always existed among the users of Heath
systems. The helpful sharing of user information has always been one of
the support functions of the Heath Company.
The software base for the Z-100 remains very large. The Z-100 Operating
Systems supported are CP/M-85 (8-bit), CP/M+ (8-bit), CCP/M (Concurrent),
MP/M (Multiuser), CP/M-86, MS-DOS V1 (Z-DOS), and MS-DOS V2 and V3. Other
operating systems such as UNIX have been implemented using other S-100 CPU
cards on the Z-100. By far the most popular OS has been the versions of
MS-DOS. All generic MS-DOS programs, language compilers, and several
programs for the IBM-PC (including the Norton Utilities) run flawlessly
under MS-DOS on the Z-100. Most big software packages have Z-100 versions
that support better color and graphics than the IBM-PC versions (Lotus 123,
MS-Windows, dBASE II, GW-BASIC, Multiplan, Turbo Pascal, HyperAccess,
WatchWord, WordStar (shudder!), etc... The excellent system architecture
of the Z-100 and the design philosophy of hardware to simplify the
software (instead of software to make up for the lack of hardware as used
in the IBM-PC design philosophy) makes the Z-100 a joy to program. The
quantity and high quality of Z-100 public domain software reflects the
excellence of the Z-100 user community and the attitude of sharing that is
typical of the Heath Computer Traditions. The INFO-HZ100 Public Domain
Software Library extols this quality with all the wonderful and really
amazing programs contributed by the INFO-HZ100 readership (BESTERM being a
prime example, as I use it exclusively for all my terminal connects and
up/downloading with all of the systems I use).
The excellent design engineering of the Z-100 combined with the loyalty and
information sharing of its users continues to allow the Z-100 to be
enhanced and continue to be a high performance system.
Many cheers,
Gern
P.S. - Next: The Evil Blue Empire and the Darker Side of the Z-100.
-------vix@ubvax.UB.Com (Paul Vixie) (11/26/87)
In article <12353175450.14.GUBBINS@RADC-TOPS20.ARPA> GUBBINS@RADC-TOPS20.ARPA (Gern) writes: > >Zenith H/Z-100 Upgrade Series Part 1 23-NOV-87 >INFO-HZ100 Gern This is a great article. I had a Z-100, though I donated it to my family's business a while back... I can recover it easily enough, though, if this statement bears out: >Other >operating systems such as UNIX have been implemented using other S-100 CPU >cards on the Z-100. The Z-100 had one of the nicest keyboards I've ever used. If I could run UNIX on it, I would consider adding hard disks and whatnot and trying to use it again. Can anyone fill me in on the details of UNIX for the Z-100? I assume that I would need a 68000 coprocessor or something, but I'd like to know: what CPU? From whom, and for how much? what UNIX? BSD is too much to hope for, but what CAN I expect? what other hardware is supported? (serial port boards, etc) If I receive mail on this, I will summarize to the net (or mailing list, for those of you not on USENET/inet). Thanks in advance. -- Paul Vixie Consultant Work: 408-562-7798 vix@ubvax.ub.com Ungermann-Bass Home: 415-647-7023 ames!pyramid!ubvax!vix Santa Clara, CA <<I do not speak for Ungermann-Bass>>