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Re: [N8VEM-S100:7194] Re: question about PC-AT V2



thanks John !  quick update for you folks who may have a similar config :
- PCAT V2 works fine until 6Mhz. I had to setup K1 on the 8086 CPU board so that the CPU runs at 6 Mhz and not 8 Mhz. I think it really comes from the PCAT as my Z80 CPU board runs at 10 Mhz without a glitch with the 4Mb and the IDE boards. I did not use a 74F11 (, still ave a LS11, I ordered a couple of F11 on eB) so that may be the issue
- the 8086 BIOS translates wonderfully most of the INT 10H calls, even with my Propterm-derived code. However, some cursor-related functions needed some tweaking, namely : the cursor set functions are based on 1, not zero, I simply added a INC AL in a couple of places in the BIOS code, and FDISK now display normally.will need to implement the color selection calls.
- Turbo pascal 1.0 for DOS does not display well, as it appears TP uses a lot of INT10 / get cursor calls and this is not implemented yet. Still need to figure out why my Propeller driver sends only the last byte R of the cursor positon reply message (it should be "ESC[y;xR"...)


Le samedi 6 juin 2015 17:31:20 UTC+2, monahanz a écrit :

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: n8ve...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Philippe Elie
Sent: Saturday, June 6, 2015 7:53 AM
To: n8ve...@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

 

cheers

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"

then:-

"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.

 

John

 

 


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 

 

thanks 

Philippe

 

 

 

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