Interesting. The M100 only has a 64 byte buffer. Maybe the NEC is a bit
more resistant to losing characters when doing flow control.

-- John.

On Jan 23, 2019 10:39 AM, "Kurt McCullum" <[email protected]> wrote:

Yeah me too so I just double checked. Page 219 of the 8201 Technical
Reference book says:

"Serial input buffer from ^XFE4C to ^XFFC3, is reserved by System ROM as
serial input buffer"

Doing the math I get 177 bytes so my original post was wrong. But still
plenty for what I am doing.


Kurt


On Wed, Jan 23, 2019, at 10:06 AM, Stephen Adolph wrote:

I'm surprised by that number.. UART circular buffer is only 64 bytes IIRC.

On Wed, Jan 23, 2019 at 1:04 PM Kurt McCullum <[email protected]> wrote:


Thanks Ken,

I'm using the UART buffer right now. That has 375 bytes according to the
technical manual. That seems to be working but I'm hammering on it in
Virtual-T to make sure it does cold start the machine.

Kurt


On Wed, Jan 23, 2019, at 10:01 AM, Ken Pettit wrote:

Hey Kurt,

On an NEC 8201a?

1.  Keyboard buffer
2.  UART buffer
3.  BASIC Floating Point number calculation space:

    M100:  TEMP 1 / FAC2 (Floating Point Accumulator) location (8 bytes
each, consecutive):  FC60h
    8201a:  FB24h (I'm pretty sure there are 16 bytes available here also,
though I'm not as familiar with the NEC ROM disassembly.

Ken


On 1/23/19 8:04 AM, Kurt McCullum wrote:

I'm working on a little piece of code that loads some stored code from
the option ROM on my NEC 8201a. I was able to tweak Gary Weber's
disassembler code to get the bytes from the option ROM. But here is the
problem. The code I am pulling down runs in the ALT LDC memory space. Alt
LCD is 320 bytes in size. I only need 315 bytes of this, BUT, I need 15
bytes for the code to pull the data from the option ROM. So there isn't
enough memory in ALT LCD to put the temporary loader AND the program I want
to run after it is loaded. So I am looking for another area of memory where
I can put the 15 byte loader. Is there another safe area I can momentarily
use in RAM without causing havoc?

Kurt

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