My Only Working PIC18F Programmer(JDM with external power)

I would like to share a frustration with my PIC18F4520. I have built 3 different version of the JDM & JDM2 programmer and all of them doesn't work. The Olimex JDM(original schematic), the updated JDM with 22-100pF capacitor & 100ohm resistor, the JDM2 on Instructables. All of them doesn't work.

I have here a working programmer for the PIC18F4520, not sure if it works with other PIC18F and other PIC version. I'm not entirely sure what programmer this is. I got it from my lecturer's notes, it was mentioned there as the JDM programmer. It requires a 15V external power source. All the ground in the schematic is connected to the power source ground, not RS232 or PIC.

I replaced the BC546 with 2N2222A(common NPN BJT) and the BC556 with PN2907A(common PNP BJT).

I'm not sure whether you can replace 78L12 with LM7812. I believe 78L12 uses only 100mA and LM7812 uses 1A.

Can anyone help me?

P/S: I've never seen this programmer anywhere and hope it can help those trying to get their PIC18F working.

I'd say more your frustration lies with the ancient JDM type programmer and not with the 18F4520. They're simply unreliable with modern OS's and GHz computers, plus you can't use USB adapters with them (legacy ports are disappearing fast on desktops and are all but gone on laptops)