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CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Mon 04 Dec, 2017 9:20 am
by ibmpc5150
According to PCEM emulator, CPU ID is recognized as NEC V20 on PC-Tools 4.x

*CPU ID:NEC V20 on PCEM or 86box
Image

I think it can't be changed to Intel 8088.

So I wonder it is impossible to implement CPU ID as Intel 8088.

Re: CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Mon 04 Dec, 2017 2:08 pm
by omarsis81
Does it happen in al 8088 machines?

Re: CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Mon 19 Feb, 2018 8:56 pm
by ibmpc5150
@omarsis81

No.

It stills appears as NEC V20 on PCEM.

Image

I think this emulation is Not equal to Intel 8088, but NEC V20.

I hope PCEM add i8088 emulation correctly.

Re: CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Sun 04 Mar, 2018 11:44 am
by omarsis81
No, NEC V20 is not emulated, PCem is closer to 8088 than NEC V20 according to this post viewtopic.php?p=3504
This must be a minor bug in the way PC Tools detects the CPU.
MAYBE you set the clock above the 4.77 and PC Tools thinks you have a NEC V20?

Re: CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Sun 04 Mar, 2018 8:16 pm
by ibmpc5150
@omarsis81

I tested it as $4.77Mhz with another PC-Tools version too.
This seems to be bug on PCEM/86box, Not PC-Tools.

Why not test it if you doubt?

Re: CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Mon 05 Mar, 2018 1:30 am
by omarsis81
I don't doubt about what you said, I only mention a possibility, but since you already tested with 4.77 mhz there must be a PCem's bug

Re: CPU ID:NEC V20 instead of Intel 8088 on PCEM / 86box

Posted: Mon 05 Mar, 2018 1:24 pm
by EluanCM
Quick note: the recently added Xi8088 BIOS knows how to differentiate between new/old 8088s and NEC V20 and works fine with PCem (detects as old 8088)