GUBBINS@RADC-TOPS20.ARPA (Gern) (05/13/88)
Zenith H/Z-100 Upgrade Series Part 4 11-MAY-88
Gern
My computer went down yesterday, so I'm simulating it with a piece of paper
and pencil.
The Zenith Z-100 MTR-100 Monitor ROM
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The Z-100 contains a very powerful Monitor. The Monitor is the base for
all the system software and provides many functions such as:
Subroutines for Trace/Breakpoint Debugger
Subroutines for Dumb Display Output & Dumb Keyboard Handler
Subroutines for Smart Display Output & Smart Keyboard Handler
Subroutines for Vertical Retrace Interrupt Handler
Default Character Font
System Initialization
Current System State Variables
System Boot From Disk
Front Panel Emulator
Front Panel Emulator
--------------------
The Front Panel Emulator function of MTR-100 2.x provides the user with
direct interaction to the Z-100 hardware in a way similar to the functions
of old style front panel switches and light displays. It also provides
color bar display, system information, and test diagnostics (very useful
if the Z-100 can't boot and run the Diagnostic Disk).
The MTR-100's Front Panel Emulator mode is indicated by the "hand" prompt
which provides the following functions:
Boot Loads the operating system from disk.
Color Bar Displays a color bar pattern.
Dump Displays a block of memory in hexadecimal and ASCII.
Examine Examines and/or changes the contents of a memory location.
Fill Fills a range of memory locations with data.
Help [HELP] Displays list of available commands.
Input Displays input from a port.
Output Outputs a value to a port.
System Displays system information.
Test Menu driven diagnostic test section.
Version Displays Monitor version.
Xecute Starts execution at specified address. Allows breakpoints.
The Test Diagnostic section provides a menu for testing the default boot
disk, keyboard, RAM, and power-up system. The tests can be stopped by
hitting the [DELETE] key or [CRTL]/[RESET].
The disk read test repeatedly reads and checks the default boot disk and
displays the number of successfully completed passes.
The keyboard test fills the screen with the character of a key pressed.
The memory test performs a moving inversions test on the first two banks
(first 128K) of RAM and the green bank of video RAM. It displays the
number of successfully completed passes (about 5 minutes per pass).
The power-up test repeats the initial self tests performed at power-up and
displays the number of successfully completed passes.
MTR-100 Versions
----------------
The MTR-100 programming is in a ROM/PROM/EPROM at IC U190. Version 1.x is
an 8K ROM and does not contain many of the 2.x functions. The current
MTR-100 ROM is version 2.9 and is a 16K ROM. MTR-100 versions less than
2.5 do not support booting from 360K disks and do not properly support some
hard disks.
General Information
-------------------
The addresses used by the MTR-100 ROM can be mapped for read operations by
the Memory Control Latch Port. The MTR-100 can be set to appear
everywhere, in the top of each 64K segment, the top of the 1MB space
(Normal Operation), or disabled.
If the MTR-100 ROM is active and addressed then the S-100 PHANTOM* line
asserts. This allows the ROM to share the address space with any RAM at
the same address. This can be very useful for using RAM above the
motherboard limit of 768K to the top of the 8088's 1MB address space (using
all 256K of RAM on a Z-205 Card).
Motherboard jumpers J101 & J102 allow the use of 8K to 32K ROM sizes.
Upgrading The MTR-100 Monitor ROM
---------------------------------
The current MTR-100 ROM is version 2.9 and is implemented in a 16K
27128-250 EPROM. The following describes how to upgrade from a MTR-100
version 1.x or 2.x to MTR-100 version 2.9. It should remain true for
upgrades to any 2.x version. If a version 3.x should ever appear, the
jumper setting for J101 and J102 may change.
Upgrade From Version 2.x:
If the current MTR-100 version is 2.x, replace the ROM IC at U190 with
Heath part number 444-276-1 MTR-100 Version 2.9 [*]. Upgrade completed.
Upgrade From Version 1.x:
If the current MTR-100 version is 1.x then 3 changes must be made:
1) The ROM Address Selector PAL IC at U161 (part number 444-129) must
either be replaced with a ROM Address Top 32K Selector PAL IC (part number
444-129-1, about $7.00) or the 444-129 PAL IC must be 'converted' to
perform the new function.
The 444-129 IC can be converted into the function of a 444-129-1 IC by
connecting input pins 2 & 3 high to Vcc at pin 20.
a) Remove the IC from the socket and bend up pins 2 & 3.
b) Bend pins 2 & 3 together and solder them both to a small wire one inch
long.
c) Carefully solder the other end of the small wire to the top of pin 20.
Do not bend pin 20 or impede the pin from normal insertion into the socket.
d) Insert the converted IC into the socket. Pins 2 & 3 must remain above
the socket, but pin 20 must go into the socket normally.
2) Move Jumper J102. This allows the use of a 16K ROM.
3) Replace the ROM at U190 with Heath part number 444-276-1 MTR-100 Version
2.9 [*]. Upgrade completed.
[*] At the time this document was created, the latest MTR-100 version is
2.9. The cost of EPROMs is in a constant state of change (mostly for the
worst) so no prices of the Heath MTR-100 are given. Version 2.9 is a
standard 27128-250 EPROM. Persons with access to an EPROM programmer and a
borrowed MTR-100 version 2.9 may wish to consider that cloning a copy of
the MTR-100 is a violation of the ZDS Copyright as the MTR-100 contains a
copyright notice in the code.
[Personal Note: I have 3 copies of MTR-100 version 2.8 that are ROMs (not
reprogrammable) pulled from upgraded Z-100s. If you are desperate to
upgrade from version 1.x to 2.x so you can boot from 360K floppy or have
hard disk problems, I will make them available for the mailing cost.
Contact me at INFO-HZ100-REQUEST@RADC-TOPS20.ARPA on a first come, first
served basis.]
Next: Winchester Modifications required for the old motherboard.
INFO-HZ100 is a ]]] FORUM [[[ of discussion of Zenith Z-100 topics. If you
have any questions, suggestions, or information to share - Please Post!!!
Cheers,
Gern
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