I had the same problem. I do not remember what the catch was, but there is
something missing in the uChip documentation and someone on the PicList
gave me the correct hint. Maybe this fragment from the firmware of my
programmer can help. Don't be scared by all the macro's, you can easily
spot the commands to the target PIC.
regards,
Wouter.

command_program_erase
 ; remove protection
 move_const_via_w_to H'03', data1
 move_const_via_w_to H'0F', data2
 move_const_via_w_to H'0F', data3
 move_const_via_w_to H'0F', data4
 output_command_const H'00'
 call output_data
 move_const_via_w_to D'07', count1
increment_loop
 call command_increment
 decfsz count1, f
  goto increment_loop
 output_command_const H'01'
 output_command_const H'07'
 output_command_const H'08'
 call wait_for_target
 output_command_const H'01'
 output_command_const H'07'
 ; erase data memory
 call reset_target
 move_const_via_w_to H'00', data1
 move_const_via_w_to H'00', data2
 move_const_via_w_to H'0F', data3
 move_const_via_w_to H'0F', data4
 output_command_const H'03'
 call output_data
 output_command_const H'08'
 call wait_for_target
 output_command_const H'0B'
 output_command_const H'08'
 call wait_for_target
 return


----------
> From: mahfoud rahal <mahfoud_rahal@HOTMAIL.COM>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: PIC 16C84 Bulk Erase
> Date: Sunday, January 24, 1999 17:27
>
> Hi,
>
> I'm working on a PIC16C84 programmer project. All programming commands
> given in DS30189D documentation from Microchip are working fine except
> for "BULK ERASE PROGRAM MEMORY" and "BULK ERASE DATA MEMORY" witch are
> 001001 and 001011 respectively.
>
> For example, in chapter 2.3.1.8 (BULK ERASE PROGRAM MEMORY)
> the doc says:
> 1- Do a "Load Data All 1's" command
> 2- Do a "Bulk Erase User Memory" command
> 3- Do a "Begin programming command"
> 4- Wait 10 ms to complete bulk erase
>
> so, my programmer send:
> 1- 000010 0111111111111110
> 2- 001001
> 3- 001000
> 4- wait 10 ms
>
> When I read back the chip, no location of the Prog Mem changed,
> am'I missing something or is there some mistakes in DS30190D.
> Any idea ?
>
> Note: I can do the equivalent operation by writing 3FFF in all program
> memory locations but this consumes much more time.
>
> Thanks for your time and attention.
>
> ______________________________________________________
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