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- H/Z-100 Service Bulletins

H/Z-100 Service Bulletins

H/Z-100 Field Service Bulletins

General Notes:

-- The following article appeared as an insert to issue #42, November-December

1995, of the "Z-100 LifeLine".

Z-100 Field Service Bulletins

Some of these bulletins contain out-of-date information, however, I left it in for two

reasons - I don't know for certain if the information still applies, and older machines

and publications are still out there to which the information may still apply - such as

the Z-100 Interim Service and the Service Data Manuals, which seem to be

completely different from the Z-100 Service Manual I received from Paul. Also, while

you may not have some of the manuals mentioned, I thought the information may

still be valuable for your other manuals or notes. Where I have updated information,

I have added it.- ed.

FSB-Z100-001: Disk Drive Specifications

The specifications in both the Service Data Manual and the Z-100 Product Info

Manual stated the disk controller will support up to four 8" drives and four 5.25"

drives. At that time, it was a hardware specification rather than a software

specification. Early software only supported 2 each of the 5.25" and 8" drives.

FSB-Z100-002: Blooming of Display

Some All-In-One computers exhibited "blooming" of the video display for about 20

seconds after turn on. This condition was considered normal.

FSB-Z100-003: Metal Filings in Cabinet

When a Z-100 microcomputer is disassembled, you may notice small metal filings on

the bottom of the cabinet on either side. These filings were from the self tapping

sheet metal screws that were used. Carefully remove any metal filings with a

vacuum cleaner or cloth. This problem has been corrected in later production by

using regular sheet metal screws.

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Summary of content (21 pages)

PAGE 1
H/Z-100 Service Bulletins H/Z-100 Field Service Bulletins General Notes: -- The following article appeared as an insert to issue #42, November-December 1995, of the "Z-100 LifeLine".
PAGE 2
H/Z-100 Service Bulletins FSB-Z100-004: Changes to Service Data Manual Please make the following changes in your Z-100 Service Data Manual: - On page 3-159, middle column, change U219 from 74ALS74 to 74S74. - On page 4-13, third paragraph, change "...logic zero on VDRAMSEL (U337-4) and..." to "...logic zero on VIDRAMSEL (U377-4) and..." - Schematic MB1: -- Locate C178 & C179 at the crystal inputs to the 8085 CPU (U210).
PAGE 3
H/Z-100 Service Bulletins - Schematic VB1 Locate VIDRAMDRY at P305-62 and remove the overbar. This line asserts on logic one. Refer to the table shown below as you update your schematic. IC U345-2 U345-4 U345-9 U345-19 U301-13 U337-1 U337-3 U337-14 U337-16 U371-14 Location 68A21 PIA 68A21 PIA 68A21 PIA 68A21 PIA Paral/Ser.Conv.
PAGE 4
H/Z-100 Service Bulletins FSB-Z100-006: Test Operates Erratically When the H/Z-100 is disassembled and reconnected with extended length cables to be used as a test bed, the unit may operate erratically, making it difficult to troubleshoot. Symptoms include failure to boot a disk, or the CRT may print characters at the wrong baud rate, or the CRTC may not initialize properly, among others. One cause may be the length of the two 40-pin ribbon cables connecting the video board to the motherboard.
PAGE 5
H/Z-100 Service Bulletins 10 20 30 40 50 60 70 80 90 'CROSSHATCH CLS FOR I=0 TO 640 STEP 30 LINE (I,0)-(I,240),7 NEXT I FOR I=0 TO 250 STEP 15 LINE (0,I)-(630,I),7 NEXT I GOTO 90 10 20 30 40 50 60 70 80 'DOTBAR CLS FOR I=0 TO 39 FOR L=0 TO 24 PRINT ".
PAGE 6
H/Z-100 Service Bulletins FSB-Z100-014: Unit Hangs Up After Lengthy Operation Check the programmable interrupt controllers U208 and U209 (HE 443-1012). These ICs may be defective. FSB-Z100-015: Z-207 Floppy Disk Controller Card; 12-volt Line Shorted Some ribbon cables connecting the 8" interface to the rear chassis have too much wire protruding past the controller board connector. This extra wire may pierce the board resist and short to the 12 Vdc line.
PAGE 7
H/Z-100 Service Bulletins In some of these revisions, the firmware will either initialize a circuit that wasn't previously initialized or initialize it differently than before. The result is that the logic states in these circuits may not match those shown in the Z-100 Interim Service Manual. In the Interim Service Manual, HE 860-15, volume one, there is a procedure outlined on pages 2-112 and 2-113 describing power measurements of the power supply with the supply unloaded. DISREGARD THIS PROCEDURE.
PAGE 8
H/Z-100 Service Bulletins positive and negative leads of the 10 uF capacitor are positioned to the left of the component side of the board (with the 100-pin connector down). This update was performed only "as needed." (I don't know about earlier boards, but the 85-2807-2 and -3 boards already have both capacitors installed, as C32 and C321. Check earlier boards, the -1 board also may have it installed - ed.
PAGE 9
H/Z-100 Service Bulletins -- Locate U22-38. Change "ORG" to DRQ." -- To make the schematic agree with the printed circuit board, change the schematic jumper numbers as follows: FROM (Schematic): J1 - J8 J9 J10 TO (Circuit Bd): J3 - J10 J1 J2 Schematic Location: Interrupt Jumpers Near U19 (RDY delay) Near U11-1 on 8"/5" line - On page 7.12 and 12.34 of the Z-100 Interim Service Manual, add the following commands to the Command Summary charts appearing on these pages.
PAGE 10
H/Z-100 Service Bulletins 1045 and HE 443-1075. Cross out part number HE 443-1075. FSB-Z100-030: Z-207 Manual Correction; Transistor (Q2 and Q3) Markings In the Z-207 Floppy Disk Controller Card Manual HE 595-2909-01, make the following changes: - Page 7: Left column, under "Transistors", Change: To: C3 C3 417-937 417-937 2 2 MPS2369 MPS2369 or PN2369A Q2, Q3 Q2, Q3 - Page 18: Left column, fourth and fifth steps, Change: To: ...MPS2369 transistor... ...MPS2369 or PN2369A transistor...
PAGE 11
H/Z-100 Service Bulletins To configure the Winchester disk drive, select the proper hardware unit and refer to the table below: Pin Pair: 1-16 2-15 3-14 4-13 5-12 6-11 7-10 8-9 Hardware Unit Number 1 2 Open Open Short Short Factory Set Factory Set Open Open Open Open Open Short Short Open Pin pairs 3-14 and 4-13 are set at the factory and the programming plug is properly configured for the drive in which it is installed.
PAGE 12
H/Z-100 Service Bulletins FSB-Z100-035: Z-205 Configuration Help In order to help clear up some misunderstandings about the Z-205, the following information will aid in setting up the proper configuration for any Z-100 use. (FSBS100-001 attempted further clarification and is incorporated in this discussion - ed.) Later Z-205 boards used a different style DIP switch that caused additional confusion when configuring this card.
PAGE 13
H/Z-100 Service Bulletins 4 5 6 7 OFF Hex Binary SW1 positions: --* --* --* --* /ON 9 1001 7654 4 5 6 7 *---* --* *-OFF /ON 9 1001 3210 The third Z-205 card installed has an address of 9Ah, having RAM Banks B, C, D, and E. Since the first bank on the card is B, then SW2 is set to 0Bh.
PAGE 14
H/Z-100 Service Bulletins - Page 11: Under SW1, the example shown is not representative of proper configuration necessary for the Z-100. - Page 15: The FILL routine will only work with ROM versions 2.2 or later. For earlier version, one must use the CHKDSK utility. - Page 16: Under "Final Configuration, Multi-card", correct the first statement to read as follows: -- Set dip switch SW1 positions 7, 4, 3, and 0 to the OFF (1) (LEFT) position. Set all the others to the ON (0) (RIGHT) position.
PAGE 15
H/Z-100 Service Bulletins FSB-Z100-039: Schematic Corrections - U130 Please make the following changes to schematic MB3 in your Z-100 Interim Service Manual. - Locate U130 in the Refresh Timing and Arbitration circuits (upper center of the schematic). Change the part number from HE 443-1039 to HE 443-1049. - Locate U130 in the Refresh, Wait Timing & Error-Generation circuits (upper right of the schematic). Write "HE 443-1049" below the generic number (ALS37).
PAGE 16
H/Z-100 Service Bulletins If the pulse width at CP3 cannot be adjusted, or is missing, check for an open circuit to U3-17 or an open wiper at R3. FSB-Z100-042: Z-207 Floppy Disk Controller Card Schematic Corrections - U22 and RP3 On the Floppy Disk Controller schematic (#585-21) supplied with the Z-100 Series Technical Manual, the line marked "EARLY" on U22 should be pin 17 instead of pin 19.
PAGE 17
H/Z-100 Service Bulletins FSB-Z100-047: CP/M Won't Boot Properly The 12H6 PAL IC (HE 444-128) at U186 on the motherboard has frequently caused the CP/M booting problems. On the motherboard (HE 85-2653-1), check Y101 (10 MHz crystal, HE 404-645), for proper frequency and output. Also, check U210 (8085 CPU, HE 443-1010) for poor socket contact or defective IC.
PAGE 18
H/Z-100 Service Bulletins 156163" indicates an HE 150-156 Winchester and HE 150-163 floppy are installed. A cross-reference of drive numbers is provided below. Any Z-100 series computer not having a drive code have an HE 150-142 floppy and/or an HE 150-156 Winchester.
PAGE 19
H/Z-100 Service Bulletins permit machine insertion of the part. FSB-Z100-057: Z-100/RS-232 Modification A situation may occasionally be experienced with ZW-110/120 models that requires a modification to the RS-232 portion of the Main Board as follows: - Symptom: Ports J1 and J2 do not function if modem is powered up prior to the Z100 being powered up. - Analysis: Some modems have been found to place a negative voltage on the +12 V line from U228 on the motherboard.
PAGE 20
H/Z-100 Service Bulletins If "Device Controller Error" is presented or there is no prompt, check DS1 (HE 60621) for incorrect markings. A number of switches have been found to be mismarked, or assembled with the cover upside down. A quick check is to check continuity of each section. When DS1 is set as required, sections 0-3 and 6 should be shorted when positioned toward the bottom of the board; all others open.
PAGE 21
H/Z-100 Service Bulletins FSB-MON-004: ZVM-135 Color Monitor w/Dark Vertical Band If a dark vertical band, approx 1/2" wide, develops on the CRT's left edge, it may be caused by the CRT's blanking signal. If this problem appears, perform the following modification: - Remove the 9-227 module and replace R3473 (3.9K) with a 10K resistor. Reinstall the 9-227 module.