General Category > Lisa Troubleshooting and Repair

BLU and Priam Datatower puzzlement

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sigma7:

--- Quote from: Al Kossow on June 16, 2024, 12:33:50 am ---there is something wonky going on with the interface.

--- End quote ---

I may be mistaken, but I have the impression you are using a prototype reproduction interface card that hasn't been tested before... any chance you could borrow one of the Priam cards from the museum's collection to see if it behaves differently?

https://www.computerhistory.org/collections/catalog/102673923
https://www.computerhistory.org/collections/catalog/102673924

The RAM failure error is what I observed with the extended write signal that corrupted memory... although I can't imagine they were shipped that way. Perhaps there is some part that was marginal and performance decayed.

Similar to what I think you're reporting, I have a vague recollection that I found the RAM failure wasn't reported in response to the software reset command, but turned up later in response to trying to actually do something... I assumed I had somehow missed it as a response to the software reset, but maybe it does behave that way.

Regarding accessing registers twice/redundantly:

Before attempting to interact with the Priam controller, the host must check to see that the "register file" is not busy.

Then (BLU at least) calls a preliminary command setup routine that will write zeros into all the parameter registers, which will also (re)check that the register file is not busy before writing those null parameters.

After performing a command, BLU reads the interface status and transaction status registers to see if the command succeeded, and if not, jumps into the error reporting code which reads those registers again to ensure it has the latest values.

Those redundancies are not necessary but are there in BLU to minimize troubleshooting mysteries.

Al Kossow:
"I may be mistaken, but I have the impression you are using a prototype reproduction interface card that hasn't been tested before... any chance you could borrow one of the Priam cards from the museum's collection to see if it behaves differently?"

I guess that is the next logical step. I have an untested prototype and it is possible there was an error somewhere in the
reproduction. I don't have a Lisa with easy access to plug a logic analyzer onto the card

sigma7:

--- Quote from: Al Kossow on June 15, 2024, 03:06:14 pm ---Will the DS101 pass self-test if no drive is connected?

--- End quote ---

It appears that without a drive attached the controller will get through the Software Reset command successfully, then fail at Sequence Up...

Here are some results from various configurations with no drive connected:

Priam card in slot 3

* Nothing connected or With Cable connected at host end only
Attempt Boot (Command 8) - 3 beeps, delay, Error 80
BLU - Hd Identify : No device detected at that port


* With cable connected to DS101, but powered off
Attempt Boot (Command 8) - 3 beeps, delay, Error 82
BLU - Hd Identify :  Error Code 8000E5CB


* With cable connected to DS101 S#000298, powered on, no Hard Disk or tape interface connected
Attempt Boot (Command 8) - 3 beeps, delay, Error 82
BLU - Hd Identify :  Error Code A2FFE5CD
-- Priam Docs say Error 22 is "Device Not Present"


* With cable connected to SMART S#008842, powered on, no Hard Disk or tape interface connected
Attempt Boot (Command 8) - 3 beeps, delay, Error 82
BLU - Hd Identify :  Error Code A200E5CD
-- Priam Docs say Error 22 is "Device Not Present"
(Don't know how to tell which type of board this is: SMART, SMART-E, etc.)


* With cable connected to DS101 S#0001312, powered on, no Hard Disk or tape interface connected
Attempt Boot (Command 8) - 3 beeps, delay, Error 82
BLU - Hd Identify :  Error Code 9D01E5CB
-- Priam Docs say Error 1D is "PROM checksum error" - persists after reseating EPROMs
-- this board has remnants of a toe-tag string tied to one of the corners.


From earlier BLU Priam Error list:
Priam Errors      $yyzzE5xx   ; xx are error code, yy is $80|transaction status (might be the same as the error code), zz is register 3 supplementary status

PriamErrSoftR   EQU   $E5CB      ; Priam error from software reset
PriamErrSeqUp   EQU   $E5CD      ; Priam error from sequence up

Al Kossow:
https://oldbytes.space/@bitsavers/112672777398617184

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