Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!bloom-beacon!oberon!cit-vax!ucla-cs!zen!ucbvax!RADC-TOPS20.ARPA!GUBBINS From: GUBBINS@RADC-TOPS20.ARPA (Gern) Newsgroups: comp.sys.zenith.z100 Subject: ZUpGrade Series - Part 1 Message-ID: <12353175450.14.GUBBINS@RADC-TOPS20.ARPA> Date: Tue, 24-Nov-87 09:59:26 EST Article-I.D.: RADC-TOP.12353175450.14.GUBBINS Posted: Tue Nov 24 09:59:26 1987 Date-Received: Fri, 27-Nov-87 22:52:27 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 112 Zenith H/Z-100 Upgrade Series Part 1 23-NOV-87 INFO-HZ100 Gern Introduction: ------------- 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. ------- Zenith H/Z-100 Upgrade Series Part 2 20-NOV-87 INFO-HZ100 Gern The Evil Blue Empire and the Darker Side of the Z-100 The Evil Blue Empire -------------------- The competitive situation when the Z-100 was introduced in 1982 can be summarized as follows: The IBM-PC and Apple III did ALMOST as well in monochrome as the Z-100 did in 8 colors. The Z-100 is always in 'graphics mode' ('text' being so much graphics) eliminating all the problems of mixing text and graphics and different screen modes of operation of the other microcomputer systems. As an added bonus, the Z-100's character font and keyboard codes are both completely software redefinable. The Z-100 contains two RS-232C serial ports, a Centronics compatible parallel printer port, light pen input, and composite and RGB video outputs. These peripherals are built into the machine so that separate S-100 cards are not needed. The IBM-PC/XT/AT contains no peripheral support, requiring extra cards to provide all I/O and video at additional cost. The Apple III did not survive very long. The IBM-PC has been modified and enhanced many times over from the original 16K, cassette tape based, 4.77MHz, 5 slot machine in an effort to make it fast enough and usable enough to fill the current computing demands of the present. The IBM-PC/XT, AT, PS/2 video (or initially the lack thereof) has spawned the MDA, Hercules, CGA, PGA, EGA, MCGA, and VGA Video - each mode mostly being incompatible with the others and creating a software nightmare. Every evaluation comparing the Z-100 and the IBM-PC rates the Z-100 as the technically superior machine. This resulted in major contracts for the Z-100 with the military, Clarkson University, and many others. The Z-100 was made the Air Force/Navy Standard Microcomputer System. Under the terms of the contract, Zenith Data Systems, would supply a minimum of 6000 (over 10,000 were actually ordered) Z-100s over a period of three years. The total amount of the contract was estimated at $29,276,679. The Z-100 is disk file compatible to the IBM-PC/XT machines. That is, the machines can both directly read and write each others disk files under the MS-DOS based operating systems (MS-DOS for Z-100, PC-DOS for IBM-PC/XT). Any program that is written to be MS-DOS compatible will run under both the Z-100 and IBM-PC. Any program which bypasses the operating system software and uses hardware particularities (Graphics, etc...) or ROM based routines will only function correctly on the machine it was designed for. The versatile structure of the Z-100 allows a great deal of freedom in redefining the hardware and software making PC emulation in software very possible (ZPC V2 is a good example). Unfortunately, the field is now dominated by the IBM and clone designs. IBM's influence on the market was far greater than any company realized at the time. IBM was spending more money in advertising the IBM-PC than ZDS's total computer sales. ZDS (as well as Tandy/Radio Shack, Texas Instruments, and Sanyo - each with non-PC compatible MS-DOS machines) realized from the start that it was impossible to out-advertise IBM. IBM spent nearly $50M in advertising the PCjr. alone, the machine that failed in the marketplace. Z-100 Little Known Features --------------------------- The superior design of the Z-100 includes several innovative circuits that have never really been put to use at the present time. The Z-100 hardware includes memory management, extended addressing, and light pen support. The light pen is only now starting to be supported. The Z-100 RAM system has bank switching memory management ability for use in muti-user operating systems. This system allows for the dynamic rearrangement of sections of the RAM addressing scheme. This system was used by the very obscure Z-100 MP/M Operating System that never caught on. There is extended addressing circuits which provide up to 16 Megabytes of addressing capability, in accordance with the IEEE-696 S-100 standard. The 8088 CPU accomplishes this by latching data onto address lines A20 through A23. The 8085 similarly can use this latch to address a location above its 64K of address space. This system can be used to provide up to a total of 16 banks of 1Megabyte of RAM and or up to 16 virtual Z-100s running on one machine. To my knowledge this hardware feature has NEVER been used. The light pen port permits using a light pen with the Z-100. When the light pen is placed near the CRT and detects a pixel, it strobes the CPU and the video board. Circuits on the video board store the location of the detected pixel. The user must supply the software to process this information (such as moving the pixel or drawing a picture). The program must set up the proper interrupts, handle timing, and take care of bit locations pointed to by the light pen. GW-BASIC V2 for the Z-100 now contains light pen support. HUG and other vendors currently have light pen support packages for the Z-100. The Darker Side Of The Z-100 ---------------------------- Barry Watzman did the architectural design of the Z-100. In a Sextant interview, Watzman states that the Z-100 design goal was to provide the best combination of display, memory, and disk I/O. The 8085 was included to as a bridge to existing CP/M software. When the Z-100 was introduced there was very little 8088/8086 software available. The Intel 8087 Math Co-processor was not included in the original design because the chip was very expensive at the time, lack of PC board room, and lack of software to utilize it. Running at faster than 5MHz was planned from design start. During development, a Z-100 was running at 11MHz. Barry Watzman left ZDS mostly because ZDS management did not believe in the Z-100, and abandoned it in favor of higher profits as a PC clone maker. ZDS never did all that was possible to make the Z-100 run PC software. The Z-100 could easily be make to include IBM ROM BIOS support in the IO.SYS module making it very PC compatible (Hint for software developers!). The Z-100 design is not perfect and has its drawbacks. It (like the IBM-PC/XT) is not a true 16-bit machine. The Intel 8088 is a hybrid 8-bit CPU with the functional capabilities of the Intel 8086 (a true 16-bit CPU). The Z-100, with its IEEE-696/S-100 bus, will accept other CPUs as slave processors which must be able to utilize the Z-100's fixed 5MHz or 8MHz system clock. The Z-100 does not have a detachable keyboard, which may be an undesirable feature to some persons. The machine has a high capacity cooling fan which makes it rather noisy in quite environments. The Z-100 has a FCC RF emission classification of a type B machine - for use in a commercial environment. Use of a Z-100 in a residential area may cause some interference to radio and television reception. The Heathkit version (H-100) has a metallic coating sprayed on the inside of the case and the FCC classifies it as a type C machine - for use in a residential environment. The terminal characteristics are that of an H-19 (enhanced DEC VT-52) and not ANSI, but the Z-100 can be made to emulate the ANSI (DEC VT-100) terminal with the proper software or the ZANSI Driver. MS-DOS caught on unexpectedly quickly and caused the rapid demise of the CP/M Operating System 8-bit world. The Z-100's 8085 CPU quickly became a wasted effort which PC board space would have been better used on an 8087 Math Coprocessor. The 8087 support baby board add-on is a kludge, but it works. The Z-100 with its single motherboard and piggy-backed video board makes system functions difficult to replace or upgrade. If the completely carded designs of the S-100 machines and the ZDS PC compatible machines had been used in the Z-100 design, it would have greatly increased the flexibility and lifetime of the machine. The ZUpGrade Series ------------------- Z-100 is now over 5 years old but its advanced features still allow it to be easily enhanced and remain technologically current with some effort on the part of the user. The Z-100 can already be enhanced and expanded by: converting it into a portable, making a detached keyboard, up to two 65MB harddisks, 1 MByte RAM, almost unlimited RAMdrive space, music & sound effects, advanced speech, analog and digital joysticks (tracballs), real-time clocks, mice, high resolution non-interlaced multisynched video, and can run quite a lot of IBM-PC software with only a software driver. The Z-100 can continue to be enhanced beyond its original design by: 10.7MHz operation, 64 or more colors per pixel, video output lookup tables, 10MBit/sec Ethernet LAN with TCP/IP, and more. In the software realm, MIMIX (a PC version of UNIX) should be very easy to port to the Z-100 with a little effort by good programmers. I am slowing working on these future upgrades. I do not have all the answers, just most of them. The Z-100 is a wonderfully complex machine and I do not, as yet, understand all of its operation. This Z-100 Upgrade Series that I am attempting to crank out is my effort to help other Z-100 users get the most out of the Z-100. The INFO-HZ100 email group of which this is a part is a FORUM for discussion, I can't come up with all the wonders on my own (especially software). The only programming language I am really good at is Solder. If WE are going to get the most out of our Z-100s, then everyone must help me out, ask questions (I make mistakes on rare occasions), add to the discussions, and experiment! Let US continue to keep the Z-100 alive and powerful! Cheers, Gern P.S. - Next: The beginning of the stuff you really want to know. All about the Z-100 Switching Power Supply ------- Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!pasteur!ucbvax!RADC-TOPS20.ARPA!GUBBINS From: GUBBINS@RADC-TOPS20.ARPA (Gern) Newsgroups: comp.sys.zenith.z100 Subject: ZUpGrade Series Part 3 Message-ID: <12371258578.6.GUBBINS@RADC-TOPS20.ARPA> Date: 1 Feb 88 14:33:02 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 204 Zenith H/Z-100 Upgrade Series Part 3 26-JAN-88 Gern It is well known that the overall quality of electronic equipment is in direct proportion to the capability of the power supply. The Zenith Z-100 Power Supply ----------------------------- The Z-100 power supply provides regulated voltages for the Z-100 main system components and the S-100 expansion bus. The power supply comes in two basic external designs, one for the All-In-One (Z-120) and one for the Low Profile (Z-110). The two power supplies look different on the outside, but internally they are identical. The power supply of the Z-100 is a Switching Power Supply. In this type of power supply, the rectified line voltage is switched on and off at a very high frequency. The resulting squarewave is then filtered into a DC voltage. This type of a design results in a power supply that is very efficient and much lighter in weight than linear supplies. The Z-100 Power Supply is rated at 240 Watts. It will operate from 120VAC or 240VAC (switchable) line input at 50Hz or 60Hz. It has its own internal high capacity cooling fan (which makes it rather noisy in quite environments). By comparison, the power supply rating of the IBM-PC is 65 Watts, IBM-XT is 135 Watts, Zenith Z-150 is 165 Watts, IBM-AT and Zenith Z-248 is 200 Watts. ZDS states that the power supply is not considered to be field serviceable. If it ever becomes defective, it should be exchanged or returned to an authorized service center. The current going rate to replace the Z-100 power supply through ZDS/Heath/Factory Service is about $280.00. [ ZDS does not provide any internal information or schematics on the Z-100 power supply. However, I have obtained complete schematics and the circuit description. I will provide the schematic as part of the promised H/Z-100-info-packet USnailing and I will place a file containing the Circuit Description into the PD Library. The complete theory of the Z-100 power supply operation can be found in this file. ] Z-100 Power Supply Outputs: --------------------------- VDC Variance Amps Max Max Ripple -------------------------------------------------- +5VDC +3%,-3% 12 100mV pp +12VDC +5%,-5% 5.2 120mV pp (Requires +5V@6 Amp Load) +8VDC +10%,-5% 8 120mV pp +16VDC +20%,-10% 1 150mV pp -16VDC +20%,-10% 1 120mV pp +12VDC +5%,-5% 1.5 50mV pp (Z-120 Supply Only) Unofficial Notes on the Z-100 Power Supply: ------------------------------------------- Both the Z-110 and Z-120 power supplies are internally the same, however there are different versions of each. The Z-120 (All-In-One) contains an extra +12VDC connector to power the video monitor. The case of the Z-110 supply is a rectangle, whereas the case of the Z-120 is like a small triangle on top of a flat rectangle. The Z-120 supply case is made not to conflict with the space used by the video monitor (a Z-110 would conflict). The Z-110 supply case is designed not to conflict with the space used by the disk drives (the Z-120 would conflict). I am not very familiar with the history of the Z-120 supply, however, there are three different versions of the Z-110 supply. The original Z-110 supply case was Black with no extra power connector for the winchester controller board. This +5VDC connector can be easily added to the Black unit for use with the ZDS winchester controller card (use the same gage wire!). The second version had a brass colored case and included the winchester card connector. The current Z-110 supply is silver in color. I am not aware of any functional differences from the brass version. The only Z-120 supplies I have seen have been brass in color. A Z-120 or Z-110 supply can be converted to the other simply by changing cases and transfering the +12VDC video connector. Self Field Repair ----------------- The Z-100 Power Supply IS repairable. I am not an expert in Z-100 power supply repair and it is sometimes best left to capable service technicians. However, supplies that die/fry after many hours of faithful operation seem to fail in similar ways and are usually repairable by anyone slightly skilled in the use of a soldering iron. These are my collective repair notes: The Z-100 power supply is quite safe if unplugged and disassembled. This is providing R1-R4 properly discharge C5 and C6 (the two big capacitors). Play it safe and make sure C5 and C6 are discharged with a meter and/or discharge them through a resistor. I DO NOT RECOMMEND WORKING WITH THE SUPPLY POWERED ON UNLESS YOU REALLY KNOW WHAT YOU ARE DOING WITH THE PROPER TOOLS AND ARE VERY CAREFUL. There are several hundred volts and several Amps at various points - it can easily KILL. DO NOT WORK WITH IT POWERED ON IF YOU ARE ALONE! The Z-100 supply will not turn on without a proper load. The Z-100 power supply (as well as other ZDS computer supplies) appear to have many failures due to poor/cold solder joints. Even worse, these bad solder connections in the high power circuits have caused arcing and burn-throughs. Also, some supplies have shown burn-throughs in the high power circuits induced by surges and other nasties. Inspect the components for damage (heat scoring, broken leads, etc). Inspect the PC Board for cold solder joints (dull looking solder connections), heat scoring (common!), and traces damaged by heat and arcing. I have seen a couple of supplies that in the same corner had heat/arcing damage that ate the PC board trace and/or component connection completely away. Repairing the damaged trace(s) and connections fixed the supplies. Heating more solder to cold solder joints have repaired other supplies as well. If the supply was blown by an external cause such as shorting an output, usually only the output regulator 'double-diodes' need to be replaced. If the fuse blows after replacing, then Q1 and/or Q2 are fried and must be replaced. This usually means the supply is in serious trouble and IC1 and/or IC2 and/or a pair of output diodes are fried as well. I can only wish you the best of luck. Borrow a known good supply and using a multimeter compare the internal resistances of all leads of the semiconductors (diode forward bias test preferred). Q1, Q2, and the output 'double-diodes' can only be properly diode tested when removed from the circuit, but comparison in the circuit with values from a good supply can zero in on a problem. The Z-100 Power Supply Fan Noise -------------------------------- The Z-100 Power Supply has its own internal high capacity cooling fan. It is rather noisy especially in quite environments. It is the biggest point of discontent of Z-100 users. After some research and experimentation, I had hoped that I could make a satisfactory recommendation to reduce or eliminate the noise level. These are my findings: The Z-100 power supply fan is a Panaflo FBP-08B12H made by Panasonic. The relevant specs on it are 12VDC normal, 4.5 mmH2O Air Pressure, 0.8 m^3/min Min Air Flow (32.9 CFM - Cubic Feet per Minute), 39dBA typical - 45dBA Max Acoustical Noise. This is for the Z-100's 240 Watt supply. By comparison, the Z-150 power supply fan is a Panaflo FBP-08B12L made by Panasonic. The relevant specs on it are 12VDC normal, 2.6 mmH2O Air Pressure, 0.55 m^3/min Min Air Flow (27 CFM), 32dBA typical - 37dBA Max Acoustical Noise. This is for the Z-150's 165 Watt supply. The Z-100 supply is 240 Watts of output power. That is a lot of power that can be generated for the size of the supply and a proportional amount of heat that must be removed. Excessive heat destroys components (especially sensitive are semiconductors). Zenith would have used a quieter fan if they could. Therefore I must recommend maintaining the 32 CFM air flow rating of the fan. To provide any less airflow MAY greatly shorten the operating life of the power supply. What Can Be Done To Reduce The Fan Noise ---------------------------------------- Bend the vent blades on the back of the computer so that the blades are straight out and do not impede the flow of air. Cut out the vent areas in the power supply case and replace with screen wire or other wire fan guards. This actually increases the air flow. Attach a large flexible hose (clothes dryer type, etc...) to the back of the Z-100 and route the noise elsewhere (under a desk, etc...). [ I think this is a little silly. ] You could build/buy a large and heavy linear supply that is capable of the same outputs. These were common in most S-100 computer 'mainframes'. It would probably require no fan at all. [ I'd wait until I couldn't get any broken Z-100 power supplies repaired.] The fan can be replaced with a 32 CFM, 3.14 inch square, AC fan. I tried the Radio Shack #273-242 at 32 CFM, 38dBA. Unplug (hard if glued) and remove the DC fan and replace with the AC fan. The AC fans are usually a bit thicker and may not fit if used with the plastic ring in the supply. Be Creative! The Radio Shack fan was somewhat quieter, it had a completely different 'whoosh' to it that was lower in pitch and most people should find more preferable. Solder the AC fan leads directly to the power switch. The fan will run even if the supply has shut down due to a fault. Note that Radio Shack #273-243 is a 3.14 inch, DC fan, 34dBA, but only 27 CFM. I would not recommend this, but it is much quieter, physically fits in the space of the Z-100 fan, and plugs into where the Z-100 fan did. --------------------------------------------------------------------------- Cheers, Gern ------- 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 ------------------------------------ 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 ------- Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!pasteur!ucbvax!RADC-TOPS20.ARPA!GUBBINS From: GUBBINS@RADC-TOPS20.ARPA (Gern) Newsgroups: comp.sys.zenith.z100 Subject: ZUpGrade Series Part 5 Message-ID: <12404817676.11.GUBBINS@RADC-TOPS20.ARPA> Date: 8 Jun 88 14:58:40 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 74 Zenith H/Z-100 Upgrade Series Part 5 06-JUN-88 Gern All the world's an analog stage, and digital circuits play only bit parts. Z-100 Old Motherboard Winchester Modifications Z-100 Motherboards ------------------ There are two different versions of the Z-100 motherboard. The 'old' motherboard (Part #85-2653-1) was designed for 192K and 5MHz operation. The 'new' motherboard (Part #85-2806-1) included design improvements, and support of 768K and 8MHz operation. The part number of the motherboard is indicated in the center of the component side (under the video board). The new motherboard incorporates corrections of the parallel port traces (all old motherboards had this factory performed). The pizzo-electric beeper/clicker was moved inward slightly to give the keyboard better clearance. The new motherboard includes circuit improvements to the memory timing and addressing logic, refresh clock logic, ready logic, swap logic, 256K RAM support, and wait state logic. The complete text to perform all the modifications and upgrades to the old motherboard to convert it to the functional equivalent of a new motherboard is documented in the JUL-85 issue of REMark magazine. Refresh Clock Modification -------------------------- [[[ WARNING: The following modifications should only be done by persons experienced (or courageous) to make changes to printed circuit boards. The possiblity exists of permanently damaging the system if a mistake is made. You make these modifications totally at your own risk. ]]] Use standard solid conductor wire-wrap wire (#30-#32 gauge). A soldering iron that is no greater than 25 Watts is recommended. IC pins when referenced from the bottom (Solder side) of the board appear in reverse order. This modification reverses the polarity of the refresh clock. It may have already been done to your computer, since it is necessary for proper operation of the Winchester controller. If there are jumper wires connected to pins 8, 9, and 10 of U130, this modification has already been done, and the next 5 steps should not be performed. 1. Position the main circuit board so that the solder side is up. 2. Cut the trace coming from U168 pin 11. Make the cut right next to the pad. [ This is a very small trace from the pad to a perpendicular trace. ] 3. Jumper U130 pin 5 to U130 pin 10. 4. Jumper U130 pin 8 to U152 pin 1. 5. Jumper U130 pin 9 to U225 pin 3. This completes the refresh clock modification. Power up the system and test. --------------------------------------------------------------------------- Next: Z-100 new motherboard 768K RAM and 8MHz upgrade. INFO-HZ100 is a ]]] FORUM [[[ of discussion of Zenith Z-100 topics. If you have any questions, suggestions, or information to share - Please Post!!! -------