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 -----Original Message----- From: Techtoolslist <techtoolslist-bounces@flippers.com> On Behalf Of John Robertson via Techtoolslist Sent: Sunday, February 11, 2024 6:57 PM To: Technical Tools Mail List <techtoolslist@flippers.com> Cc: John Robertson <jrr@flippers.com> Subject: Re: [Techtoolslist] 9010A Z80 pod and the !IORQ line On Feb 11, 2024, at 2:31 PM, davids@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@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@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/