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[Zeta v2] RomWBW: Timer interrupt & (separate) PPISD queries [message #8126]

Mon, 07 December 2020 06:41

scruss
Messages: 62
Registered: December 2015
Location: Toronto, Canada

Member

I finally reflashed my Zeta v2 with the current RomWBW, and the improvements are incredible! Thanks for all the hard work on this.

How might I access the timer interrupt under CP/M? I'd like to patch Richard Russell's BBC BASIC (Z80) to add in timing support. The package comes with a patch to allow this, but I'm a bit rusty on how to access the timer itself.
I asked before on the old list, and I can even find a reference to my query on the archive but not the text, so: do I have to recompile RomWBW to enable PPISD support? The stock Zeta v2 ROM doesn't find my PPISD at all.

> Does anyone know what each of the pins on the 6502 CPU chip in the Apple II Plus does?
They all plug into the socket on the motherboard to keep the chip from drifting away. - c.s.a2 FAQ of yore

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Re: [Zeta v2] RomWBW: Timer interrupt & (separate) PPISD queries [message #8152 is a reply to message #8126]

Wed, 23 December 2020 01:33

b1ackmai1er
Messages: 396
Registered: November 2017

Senior Member

Hello, did you get an answer on any of this?

Not familiar with ppisd but yes you need to assemble a new bios for your Zeta2 with this setting in your config.

SDENABLE .SET TRUE

Once enable the driver will automatically set the mode to SDMODE_PPI and the correct base address for the Zeta2 PPI.

Regarding CTC interrupts check out the ROMWBW Architecture document functions for System Interrupt Management, Real Time Clock and Timer tick functions.

Regards Phil.

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Re: [Zeta v2] RomWBW: Timer interrupt & (separate) PPISD queries [message #8166 is a reply to message #8152]

Fri, 01 January 2021 08:19

scruss
Messages: 62
Registered: December 2015
Location: Toronto, Canada

Member

Thanks, Phil. I'd worked out the SDENABLE line. Sadly something seems off with either the 3½" floppy drive or the BIOS, because when I try to access any file on the floppy I get a

+++ BAD INT 00H: @FF7A[0000:2020:2020:0500:FEF6:EC20:1804] 

CBIOS v3.0.1 [WBW]

or some other kind of hard lock. Without a working floppy or SD device, I'm going to have to buy a flash programmer to rewrite the ROM.Unless there's a magic (risky) way of writing directly from xmodem ...

Thanks for the Architecture document link. Sometimes I have difficulty finding things in projects with lots of documents

> Does anyone know what each of the pins on the 6502 CPU chip in the Apple II Plus does?
They all plug into the socket on the motherboard to keep the chip from drifting away. - c.s.a2 FAQ of yore

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Re: [Zeta v2] RomWBW: Timer interrupt & (separate) PPISD queries [message #8381 is a reply to message #8166]

Sat, 13 March 2021 16:47

scruss
Messages: 62
Registered: December 2015
Location: Toronto, Canada

Member

I finally sprung for a TL866-II programmer (which works lovely under Linux using minipro Wink

and managed to rewrite the flash. Seems that creating the file RomWBW-v3.0.1/Source/HBIOS/Config/ZETA2_ppisd.asm with the contents:

#include "cfg_zeta2.asm"
UARTCFG		.SET	UARTCFG | SER_RTS
CRTACT		.SET	TRUE		
PPIDEENABLE	.SET	FALSE		
SDENABLE	.SET	TRUE		
PPPENABLE	.SET	FALSE		
PPISD		.EQU	TRUE

lets the magic happen.

I have no idea what I did to get the custom configuration ZETA2_ppisd compiled into a ROM, though. On one system I created the file, but no amount of make would generate a ROM. On another computer, it built with no additional intervention. But it's working now, and soon I should have CP/M+ and Protext running: yay!

> Does anyone know what each of the pins on the 6502 CPU chip in the Apple II Plus does?
They all plug into the socket on the motherboard to keep the chip from drifting away. - c.s.a2 FAQ of yore

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Re: [Zeta v2] RomWBW: Timer interrupt & (separate) PPISD queries [message #8382 is a reply to message #8381]

Sat, 13 March 2021 21:25

b1ackmai1er
Messages: 396
Registered: November 2017

Senior Member

Always good to see problem resolved posted in the forum. Good luck with your next step.

The TL866-II is fantastic. Just received 10 74LS373 from aliexpress. Checked them using the logic test funtion - all bad. Save me tonne of fault finding time.

I do this with every order I receive now.

Regards Phil

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