RE: [N8VEM-S100:5513] CP/M acting weird

Yeah, I've been poking at it more and it seems a bit intermittent. I'm guessing my SD writes are the fault. My next steps are to write some code that will quickly write many sectors to the SD card. My guess is that I'm either not testing the SD status correctly and perhaps not giving it enough time to complete the write... or something along those lines. Hmmm, a simple test would be to put a nice big delay in there somewhere.... then I'll know with certainty and follow through with more research on the SD write/busy status.

Subject: Re: [N8VEM-S100:5513] CP/M acting weird
From: rich...@verizon.net
Date: Mon, 3 Nov 2014 20:07:04 -0500
To: n8vem...@googlegroups.com

I've used this method a lot on my IMSAI and I don't recall there being any particular issue with files greater than 32 blocks. Since 128*32 is 4096 I wonder if there's a bug in the SD code that's value-triggered.

Rich Cini

Sent from my iPhone

On Nov 3, 2014, at 7:59 PM, Crusty OMO <crus...@hotmail.com> wrote:

Poking at this more.... the SAVE command is acting weird at any size... seems like I've just been lucky saving some of the command files... I'm going to need to do a whole lot more digging and some more learning of CP/M before I can get to the bottom of this problem. ahh, perhaps I need to take a step back and do some more diagnostics and testing of the SD read/write routines... but that will wait for another day.

From: crus...@hotmail.com
To: n8vem...@googlegroups.com
Subject: RE: [N8VEM-S100:5511] CP/M acting weird
Date: Mon, 3 Nov 2014 19:45:52 -0500

Hi guys,

Ok, I'm trying to transfer the standard files to my virtual disk on the SD Card (8080 CPU board).

I am using Rich Cini's suggested method of getting the file into memory at 0x100 (via my monitor's Xmodem routine).
Then warm booting CP/M and doing the SAVE x filename.ext command.

This works fine for files that are 32 blocks or smaller, but when I try a file that needs to save 40 blocks, the SAVE command corrupts my directory and virtual disk.

I'm going to poke at it some more, but if anyone has any suggestions, I'd love to hear it.

PS. I have tried rewriting my firmware to use a stack in the High ram area, just following through on a hunch and previous problem about running out of stack space. I have about 300 bytes of stack space available there, assuming CP/M does not change the stack pointer. But, why should CP/M change the stack pointer? the BIOS cold and warm boot sets it according to the adapted Hardware.

Cheers,
Josh

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