Re: [rc2014-z80] Digest for rc2014-z80@googlegroups.com - 6 updates in 2 topics

[Paul Bigwood]

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On 7 Feb 2026, at 18:25, rc201...@googlegroups.com wrote:



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• TURBO - Z80 CPU Module - 4 Updates
• CF Card formatting - 2 Updates

TURBO - Z80 CPU Module

7alken <antos...@gmail.com>: Feb 06 06:46PM -0800 very interesting thread ... what was fate of that TURBO module, Phillip? did you solved that SIO/2 INT? I was surprised, sightly, by that 68B50 ... as just today also was chatting about harsh timing of (old/new) 65C02, which Alan mentioned many times; btw, may be Hitachi HD63B50 even faster/forgiving? I in fact today drafted also RCBus board with my breadboarded Bill Shen's RIZ180 for testing some newer ideas - glad it has the wait states better, interesting; P.     On Tuesday, March 29, 2022 at 6:13:44 AM UTC+2 Bill Shen wrote:

Dean Netherton <dean.ne...@gmail.com>: Feb 07 10:24AM +0700 Gees this was an old thread     I did end up developing my own turbo charged z80 module. Was inspired.   U can check it out on my site. https://www.dinoboards.com.au/stegosaur/turbo-cpu/   In can now work with the standard sio/2 module under romwbw. There is a new special build option that needs to be enabled. TURBOZ80   Dean

Phillip Stevens <phillip...@gmail.com>: Feb 06 09:35PM -0800 IIRC, I had some difficulty properly triggering specific wait states with the signals I had directed to the GAL. But, I ended up using it anyway without a variable clock multiplier, just because of the bus buffers and clean integration of clock and reset circuits on to the Module.   Then I lost interest in that topic and moved on to working mainly with 8085 CPUs <https://www.seeedstudio.com/8085-CPU-Module-for-RC2014-g-1345971>. So, I think Dean may be the only one who has a variable clock solution available. Though (like Bill) others have successfully overclocked z80s substantially.   P. On Saturday, 7 February 2026 at 10:46:43 UTC+8 7alken wrote:

Bill Shen <coinst...@gmail.com>: Feb 07 05:35AM -0800 After all these years of experience, 2X turbo is pretty much a sure thing. It may be interesting to redesign the clock module to have a turbo switch or a I2C controllable oscillator like DS1086. With DS1086 you can explore the upper frequency limit which is around 3X On Friday, February 6, 2026 at 10:35:19 PM UTC-7 Phillip Stevens wrote:

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CF Card formatting

Michelle Lawson <michelle...@gmail.com>: Feb 06 04:27PM -0800 Bug Report: #ID10T Title: Unable to temp store a variable in write protected memory Cause: Reusing, and embedding, Grant Searles form64.asm code into code that is resident in write protected memory means that temporary storage of the secNo and drvName variables are always FFh. The NOOB programmer (me) has since corrected this affront to all that is sacred in the programming world, and has made amends....   PS. I figured, if I looked at it long enough, the old bulb in my head just might go off...... Now, on to the next problem......     On Thursday, February 5, 2026 at 7:13:04 PM UTC-5 Michelle Lawson wrote:

Ed Silky <aes...@gmail.com>: Feb 06 05:48PM -0800 Very Good!!!   On Fri, Feb 6, 2026 at 4:27 PM Michelle Lawson <michelle...@gmail.com> wrote:

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[Paul Bigwood]