[Techtoolslist] 9010A Z80 pod and the !IORQ line

davids at oz.net davids at oz.net
Tue Feb 13 18:31:43 EST 2024


Did you get a chance to try this John?  I opened up my Z80QT pod and checked the CPU in it.  There is a Z84C0008PEC which is an 8mhz CPU.  And I don't think there is anything faster than that available so probably not the issue.

David

-----Original Message-----
From: Techtoolslist <techtoolslist-bounces at flippers.com> On Behalf Of John Robertson via Techtoolslist
Sent: Monday, February 12, 2024 1:57 PM
To: 'Technical Tools Mail List' <techtoolslist at flippers.com>
Cc: John Robertson <jrr at flippers.com>
Subject: Re: [Techtoolslist] 9010A Z80 pod and the !IORQ line

On 2024/02/11 11:57 p.m., davids at oz.net wrote:
> Thanks John,
> I looked through the manual before sending the mail (and posting to the FB group) and missed that paragraph.  Though now that I know it was there I found it easy enough.
>
> Can get the 9010 to read the portB from the 8255 (dip switch value), though no matter what I can't seem to set the control byte in a manner that I can actually write through the 8255.  Frustrating.
>
> Trying for operating mode 0, config 2 (PortA output, PortB input, PortC output) should just be a write to 0x10007 = 0x82.  Then writing PortC should just be 0x10006 = 0x??.  But no matter how I write the values of PortC are just tristate.
>
> Also I can't get Run UUT to work, I have 4 different of these Gameplan MPU-2's, one of which is known working perfectly.  But pulling the CPU and connecting my z80QT pod then hitting Run UUT, the board just freaks out, rebooting constantly, I assume the watchdog is hitting but even bypassing that the board just won't boot correctly.
>
> Buss / Rom / Ram tests pass fine just wont Run UUT.
>
> David

Try a faster CPU in the pod?

Its been a while since I last ran GP MPU on the QT-Z80 and can't recall if it works or not on Run UUT. I have to check a GP MPU tomorrow so will let you know.

John:-#)#

>
> -----Original Message-----
> From: Techtoolslist <techtoolslist-bounces at flippers.com> On Behalf Of 
> John Robertson via Techtoolslist
> Sent: Sunday, February 11, 2024 6:57 PM
> To: Technical Tools Mail List <techtoolslist at flippers.com>
> Cc: John Robertson <jrr at flippers.com>
> Subject: Re: [Techtoolslist] 9010A Z80 pod and the !IORQ line
>
>
> On Feb 11, 2024, at 2:31 PM, davids at oz.net wrote:
>> Z80 pod and the !IORQ line. Working on a GamePlan MPU-2 board.
>>
>>
>>
>> Address space looks like:
>>
>> 0x0000-0x1000 ROM
>>
>> 0x0004 8255 Port A
>>
>> 0x0005 8255 Port B
>>
>> 0x0006 8255 Port C
>>
>> 0x0007 8255 Control
>>
>> 0x0008 Z80 CTC Ch1
>>
>> 0x0009 Z80 CTC Ch2
>>
>> 0x000A Z80 CTC Ch3
>>
>> 0x000B Z80 CTC Ch4
>>
>>
>>
>> Looking over the schematic I can see that the chip select lines for 
>> the 8255 and CTC are tied the Z80 !IORQ pin (20).
>>
>>
>>
>> Makes sense, only interface with the two peripherals when you need 
>> too so you can overlap the address space.
>>
>>
>>
>> But from the 9010A how do I control that I am reading / writing to 
>> those devices?
>>
>>
>>
>> Thanks,
>>
>> David
>>
>>
> Z80 IO requests are above FFFFh. I think they are 10000 to 10003h as I recall.
>
> The Z80 pod manual covers this…
>
> John :-#)#
>
>> _______________________________________________
>> Techtoolslist mailing list
>> Techtoolslist at flippers.com
>> https://pairlist7.pair.net/mailman/listinfo/techtoolslist
>> FTP site is: ftp://ftp.flippers.com/TTL/TestEquipment
>> Archive site 2005-Current:
>> https://seven.pairlist.net/pipermail/techtoolslist/
>> Vectorlist Archives 1997/99 - 2016: https://www.vectorlist.org/
> _______________________________________________
> Techtoolslist mailing list
> Techtoolslist at flippers.com
> https://pairlist7.pair.net/mailman/listinfo/techtoolslist
> FTP site is: ftp://ftp.flippers.com/TTL/TestEquipment
> Archive site 2005-Current: 
> https://seven.pairlist.net/pipermail/techtoolslist/
> Vectorlist Archives 1997/99 - 2016: https://www.vectorlist.org/
>

-- 
                  John's Jukes Ltd.
7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 Call (604)872-5757 (Pinballs, Jukes, Video Games)
                  flippers.com
  "Old pinballers never die, they just flip out"

_______________________________________________
Techtoolslist mailing list
Techtoolslist at flippers.com
https://pairlist7.pair.net/mailman/listinfo/techtoolslist
FTP site is: ftp://ftp.flippers.com/TTL/TestEquipment
Archive site 2005-Current: https://seven.pairlist.net/pipermail/techtoolslist/
Vectorlist Archives 1997/99 - 2016: https://www.vectorlist.org/



More information about the Techtoolslist mailing list