Duemilanove used to work, now can't upload

Development Tools IDE 1.x
1

So everything has been working fine with my Duemilanove connected to MacBookPro OSX lion via USB port.
Then I uploaded a sketch to dump RAM.
An ancient concept called PMD (Post Mortem Dump).
Knowing that some RAM from the previous program will still be intact although
uploading the PMD sketch may klobber some RAM
and the RAM used by the PMD sketch will also klobber some RAM.

It wasn't working as I had hoped so I decided to store the index of the location I was displaying into the location.
That is:
before setup()

char RAM[1];

within loop();
...

for (m=start; m<end; m+=16){

...

 for ( i =m; i<m+16; i++){
RAM[i]=i;
int asc=RAM[i];
if ( asc....){ asc='.';}
Serial.write(asc);

I compiled that and uploaded it.
Opened serial monitor and , , my Serial.write statements were outputting,,,
and they kept outputting...

I think I pressed reset on Duemilanove. I'm not sure but maybe the sketch restarted. At this point I may have pulled the USB cable and got a kernel panic on the Mac!

After booting, shutting down and booting now,
Cannot upload even blink
IDE compiles reports

Binary sketch size: 1,076 bytes (of a 30,720 byte maximum)
avedude: stk500_recv(): programmer is not responding.

Multiple attempts to press reset button ( even feverishly several seconds after starting compile),
unplug/replugin USB cable. Don't seem to help
Pressing the reset button causes L ( LED_BUILTIN) to blink once.
When pluging in the USB cable (sometimes) RX, then TX, then L, then a couple of RX,TX blinks a pause then a blink of TX.
Nothing on serial monitor after varying the baud rate.

Do I have a tiny "brick"?

2

With your definition of the problem it rather looks like there is communication error on the com port and the Arduino IDE is not smoothly able to communicate with the Arduino you have, check out for the Arduino drivers.

EDIT: Have you tried the LOOP BACK test? if not try it.

3

Try this - press & hold the reset button until you see "Compiled xxxx byte of 32xxx" (or similar words) on the IDE screen, then release the button.

4

Loopback: jumper RESET - Ground ; digital0 RX - digital1TX
open serial monitor; speed 300 baud, enter many '='s , click (SEND).
TX, RX blink madly, monitor screen shows many '='s

baud 1200, enter many '-'s, click (SEND) .
TX, RX blink madly, monitor screen shows many '-'s
baud 57600, enter many '+'s, click (SEND) .
TX, RX blink briefly, monitor screen shows many '+'s

upload Blink sketch, oops , left jumper connected.
remove RX-TX jumper,
Whoa! It's a blinking.

Load another sketch and it works!
Thanks (wish I understood what happened!)