1. Not old. Vintage. :)

Indus GT - Diags

Description of error codes etc. for Indus GT

{From a defunct Atari board}

link to FSM: blog.3b2.sk/igi/file.axd?file=2011%2F7%2FINDUS_GT_FSManual.pdf

here's description of the error codes for the Indus GT
'G' = GET or read error,
'P' = PUT or write error
'F' = FORMAT error.

the numeric values are:-
3 = Lost Data Error
4 = Checksum Error
5 = Record Not Found
7 = Write Protect Error
9 = Verify Error

'E' = displayed when no error has occured (Hold down ERRORpush button while TRACK push button is pushed).

Disk errors G3, G4, G5, head need cleaning or disk has bad sector or alignment on the drive...H3 is on the mother board..Try replacing the H6116 or 74LS244 (U19) first and/or U23)The indus has built in diagnostics that run every time at power up.If an error occurs, an alpha-numeric is displayed on the LED..The C is displayed while the tests are running. H is displayed if atest fails. Initially, C will flash and and quickly counts 3.C1/H1 = Quick ram check.C2/H2 = Z80A index registers testC3/H3 = Floppy disk controller test.After that, the led display should briefly read 00 before stepping up to 39.If nothing of the sort comes up, then there is some problem with the Z80, ROM, PSU ICs or logic circuit.You can also run level 2 Diags.an SIO cable configured/shorted :pins 1, 2 and 7 shortedPins 3,5 and 10 shortedFit the plug,power on while holding down TRACK, ERROR and DRIVE TYPE buttons front panel buttons.C4/H4 = serial bus interface bus test.C5/H5 = Interrupt circuitry testC6/H6 = Extented ram test.This takes a while to completeif successful, an E- is displayed.A note (from reading the FSM) on how the C/H Diags work:-C3/H3) Floppy Disk Controller Test *The Built-In Diagnostics run a series of routines to test the Floppy Disk Controller. TRunning Order:1. UART issues a FORCE IMMEDIATE INTERRUPT.2. Z80A runs a short time delay loop for 52 microseconds via WD1770 with WD2797 running faster.3. FDCs INTRQ line tests FDC for interrupts. FDCs INTRQ line is not tied to the Z80As IRQ line. Test will fail on no response from FDC.4. FDC is issued a FORCED INTERRUPT command to clear the FORCE IMMEDIATE INTERRUPT condition.5. Z80A waits 52 microseconds for the FDC response.6. FDC status register read and clear the FDC interrupt.7. Z80A waits 52 microseconds for FDC response.8. FDC INTRO line tests FDC has cleared. Test will fail on no response from FDC.9. FDC track, sector, and data registers (in that order) load from 00H, 01H, and 02H respectively. Next data, sector, and track registers (in that order) are checked for pattern changes. Any errors/mismatches reult in test fail. Finally test is re-run from 01H, 02H, and 03H respectively. Test process continues until final pattern FFH, 00H, and 01H respectively.10. FDC track register copied to data register and a seek command is run. FDC will seek to the current track. Test checks that WD1770 is in Mode 1 and that the IP is re-run in status register. Test NOT required with WD2797.11. FDC index pulse (IP) line set to active.12. Z80A waits for >20 microseconds allowing for FDC response.13. FDC status register verifies index. Fails if if index not verified.14. FDC index pulse line is disconnected.15. Z80A waits >20 microseconds allowing for FDC response16. FDC status register verifies removal of the index. Fails if not verifiedIf any of these tests fail, "H3" will display on LED.Further notes:U19 and U23 are 2 74LS244 chips on the main-board and may be soldered. 74LS244 is an octal buffer/line driver for signal buffering.(U19) buffering the Atari port signals and IRQ/DRQ signals internally (to the data bus). failure results in H3 (Halt in test 3) error code(U23) located (electrically) between the 4 config switches on the back and the data-bus and the front panel switches and the data bus.PSU should be meter read as out of range gives unexpected reporting/results.if FDC at fault a chip swap is the fix. - swapping the FDC chip and RIOT.Motor SPEED ADJUSTMENT (from Baz)The drive motor speed test checks to see if the speed is within the specifiedtolerance. Theoretically the motor speed should be at 288 RPM plus or minus fourRPM. The recommended speed is 288 RPM plus or minus one RPM.STEP1.Insert a diskette into the drive.STEP2.Select the Motor Speed option of GT;DOC.STEP3.Select the Index Mark speed check.STEP 4. Locate R31 on the Analog Board (see Figure'6)9), This is the speed controlpot.
STEP 5. Adjust R31 until the motor speed is within 288 RPM plus or minus l RPM.
G3/G4/G5 - as said in my initial post are usually either
heads need cleaning/bad disks/head alignment

on the second drive - check that's not a "H3" - when some elements fail on the LED the H3 can end up looking like H0
when i wrote up this thread initially i couldn't find a H0
they only tend to come in 3 flavours
1, 2, 3

C1/H1 = Quick ram check.
C2/H2 = Z80A index registers test
C3/H3 = Floppy disk controller test.

to elimiate/identify the FDC as the problem, you can "swap in" a working FC100817 (WD2797)
from an Atari 1050 for the Indus 2797FDC
- they're interchangeable

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