Mark Pizzolato schreef op 15-12-2018 om 21:42:
On Saturday, December 15, 2018 at 12:09 PM, Wilm Boerhout wrote:
[...]
DBG(1041144)> CLK REG: todr_rd(ROM) - TODR=0xC3AA5B84
This line ^^^ and all above it are done by the MicroVAX 3900 boot
ROM and have nothing to do with ELN.
DBG(7056415)> CLK REG: todr_rd() - TODR=0x132A4
DBG(7056419)> same as above (1 time)
DBG(9598293)> CLK REG: todr_rd() - TODR=0x133F0
DBG(11998428)> CLK REG: todr_rd() - TODR=0x13526
DBG(14398563)> CLK REG: todr_rd() - TODR=0x1365C
Simulation stopped, PC: 800066EE (BEQL 800066EA)
sim> quit
Goodbye
NVR: writing buffer to file
CLK: writing buffer to file
Eth: closed tap0
The few actual reads of the TODR during ELN's execution are returning low
values (since nothing actually set the clock yet).
Do you get the same result if you don't attach the CLK device?
If the result is the same, then it would seem that ELN doesn't care to use the
hardware clock for much of anything. Maybe there is some setting within ELN
that could influence more direct use of the clock.
- Mark
Thanks Mark for clatifying this.
That might well be the case. That is why I'm interested how a real rtVAX
preserves its clock. Maybe it didn't, and you had to enter the right
time on every boot. In which case simh would be right. These systems
would sometimes run for years. Documentation is scarce, however. I
havesome leads th real rtVAX-systems, but not very soon.
Anyway, with MV3900 the behaviour doesn't change when I do not attach
the CLK device. System time starts at VMS Zero.
Let's let it rest. I will go out on this thing called The Internet and
look better for docs.
*Wilm*
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