No problem Philippe, happens me all the time. There are so many jumpers on these boards it’s hard to get all the ducks lined up in a row!
John
From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Philippe Elie
Sent: Saturday, June 6, 2015 7:53 AM
To: n8vem...@googlegroups.com
Subject: [N8VEM-S100:7194] Re: question about PC-AT V2
thanks for the feedback John. I feel a bit like an idiot ... 1) I did not jump K2 1-2 on the Prop board 2) the Propeller code I modified to display colors poorly is the issue as it does not trigger P12 properly... Need to rework this quite a bit.... I will post here the corrected code (and some description text as you requested John, been qute busy over the past weeks) ASAP
Philippe
Le samedi 6 juin 2015 10:57:57 UTC+2, monahanz a écrit :
Philippe, it's not clear to me what exactly the problem is.
"VI1 does arrive at IR1 on the 8259 but INT is not asserted"
"the 8259 seems to work fine as INT is generated and INTA"
The INTA will only be generated by the 8259A if it gets and accepts an INT.
Have you tried another INT vector.
On Friday, June 5, 2015 at 10:37:01 AM UTC-7, Philippe Elie wrote:
Hi folks,
I finished the PC-AT V2 board and started testing it with the 8086 V1 board (running monitor 10.33). All fine, RTC and timer look OK but I have trouble when testing the BIOS keyboard functions.
I use the Propeller board so jumpered VI1 and I do see the appropriate LED on the LED bar of the PC-AT blink when I hit a key. VI1 does arrive at IR1 on the 8259 but INT is not asserted. the 8259 seems to work fine as INT is generated and INTA as well as displayed by D2 and D1 when jumping VI0 to the system tick on P54.
I checked the way the 8259 is initialized : when entering the 8086 monitor, I clear the interrupt mask with "QO21 00" and I see D2 (INT) blink to reflect VI0. then I mask VI0 (QO21 01) but still get no INT when hitting the keyboard.
the 8259 seems properly accessed as all bit patterns written to 021H are read back correctly. I have the Z80 V2 board so VI0-7 are pulled up by the board (I did not install RR9 on the PC-AT board).
I'm a bit puzzled to be honest... If you guys could provide some guidance, I would be grateful
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