Thanks! That makes sense, and the program now pulls it right - partially. I have a routine (below)

1. writes data
2. reads data
3. erases data
4. reads a specific location in memory

problem is this - When I READ, I get for example "1" stored in location "2".. this makes sense.

BUT when I read from a specific location using a lookup, it returns a totally different value.. Example:

Enter 1 to write data, 2 to read it, 3 to erase, 4 to select -> "4"
Enter the memory location you want (000-255) - > "002"
Reading: 2 Data stored there: 21332

I'd expect the "002" memory location to match the one above and return a "1".. instead I get "21332"... Something is wrong with my DEC3 collection?

Thanks for helping me understand how these words/byte, etc equate to memory space.

Tom

- Updated CODE ------------------------------------------------------
'on my DataLoggers I have 16F876 or 18F252 and 2x 24LC512.
'The following code is tested.
'could you give it a try and let us know what the result was?
' -----[ Fuses ]------------------------------------------------
@ __CONFIG _CONFIG1H, _OSC_INTIO67_1H
@ __CONFIG _CONFIG2H, _WDT_ON_2H & _WDTPS_128_2H
@ __CONFIG _CONFIG3H, _PBADEN_OFF_3H & _MCLRE_OFF_3H
@ __CONFIG _CONFIG4L, _LVP_OFF_4L & 0bfh ;_XINST_OFF_4L
'
' -----[ Includes/Defines ]---------------------------------------------------------
include "modedefs.bas" 'include serout defines

OSCCON=%01111000
DEFINE OSC 8
While OSCCON.2=0:Wend

SCL var PortC.3 ' I2C Clock
SDA var PortC.4 ' I2C Data
ROM con %10100000 ' address of chip1
ADDR VAR word ' ROM Location
portout var PortC.6
portin var PortC.7
Mode con 16468 ' 4800 Baud 8N1 for Monitor Port

I2Cdelay con 10 ' Delay after I2Cwrite

Temp var byte
X var word
dta var word
stuff var word ' Test Array

CLEAR

Addr=100
loop:
SEROUT2 portout,Mode,[13,10,"** MCU started",13,10,13,10]
serout2 portout, mode, ["Enter 1 to write data, 2 to read it, 3 to erase, 4 to select",10,13]
serin2 portin, mode, [DEC1 temp]

select case temp
case 1
for X = 0 to 128
I2Cwrite SDA, SCL,ROM,X*2,[X],failw
pause 10
Serout2 portout, mode, ["write Address: ",#X*2," Data:",#X,10,13]
next x
case 2
for x = 0 to 128
I2Cread SDA,SCL,ROM,X*2,[dta],failr
Serout2 portout, mode, ["Read Address: ",#X*2," Data:",#dta,10,13]
next x
Case 3
for x = 0 to 128
I2Cwrite SDA,SCL,ROM,X*2,[x],failw
Serout2 portout, mode,["Erasing Address: ",#X*2," Data:",$FFFF,10,13]
pause 10
next x
Case 4
Serout2 portout, mode,["Enter the memory location you want (000-255)",10,13]
serin2 portin, mode, [DEC3 temp]
I2Cread SDA,SCL,ROM,temp,[stuff],failr
Serout2 portout, mode,["Reading: ",#temp," Data stored there: ",#stuff,10,13]
pause 10
case else
goto loop
end select

goto loop:

failr:
serout2 portout, mode,["failure to read",10,13]
return

failw:
serout2 portout, mode,["failure to write",10,13]
return

END