开云体育

Lee, Even with NMOS 8250 and the few TTL pieces the total power is quite small and a battery plus 5V SMP regulator will produce very long run times before battery goes too low. Haven't measured it

I've been travelling (to VCF-East) and so have missed the start of this thread. But in general... The Z80MC CPU board can be run all by itself. It's all CMOS, and draws so little current that I can

Since most of the boards and parts are CMOS running the whole thing off a battery and switch mode regulator (for power conversion efficiency) would be easiest. For mine that means replacing the 8250

Thanks Allison and Rich for your responses and guidance. I have more learning to do until I can figure out how to replace the RAM with NVRAM on the CPU board, if ever practical. In the meantime, I

Kerem, Makes no difference if the CPU is Cmos or Nmos as the bigger difference is overall power consumed, usually it is only part of the systems power needs. The z80MC only senses power good where

Rich, That can work IF the fail rate is slow enough from initial 5V to trigger level to assure enough work (save state).? Very iffy and depends on precision in the supervisory device.? Also those

To add to this a bit, assume that the loss of power is unpredictable. The Z80 needs to know when a power loss occurs in order to be able to “save state” (i.e. the registers, etc.). The z80 has a

Its done in programming.? I do not mean in BASIC. Preserving the CPU state means writing all of the registers, internal? flags, and interrupt status, to protected ram.? Fairly easy but the on

Hi Allison, I have been researching how to preserve the CPU state before power down and restore on Z80 while using NVRAM without any luck. How would that be done on the Z80 membership card? If I

Piezo speaker is somewhat inaccurate as its actually a resonator. Being much louder at its resonant frequency. They are best when well supported by their edges with airspace under and

Oh, when using NV-ram in Z80 systems one needs to preserve the CPU state before power down.? And restore that state on power up. Easier way is an all CMOS Z80 system, then battery to run CPU and all

That's a 32K byte part. similar to 62256 as used on CPU card. The SIO board comes with 64K byte part. They can be used if pinout matches as "battery backed" Ram which is what they are. I have used

Hello, Anyone using NVRAM instead of RAM in Z80MC as described Z80MC Operating Manual page 4? -Does this NVRAM replaces the RAM on Z80MC or SIO card? -Can it be used besides Micro-Basic? -Default

After a few days, it seems like adding the 22k resistor between pins 1-2 of R4A did the trick. Haven't had any more issues with the #8 button. Some things to note: R4 is a 15k sip. That's what was in

I don't know,? I will need some time to set up and test here.

It can be activated through software, but I don't recall if the firmware made that available.?

Thanks Kerem, I’ll give that a try. Paul

It is louder if the Piezo speaker is not in contact with the chips below, and suspended in the air with the ground wires. [email protected]> wrote:

I have the same problem. ?If I put my ear to it I can hear a faint beep. ?Checked all the wiring and connections, everything looks right. Paul

Yes, it actually beeps on each key press. I just couldn't hear it. Is there anything else I can do with it? Mitch