dgl
Member
Hi Mike,
Willem programmers are inexpensive and more geared towards hobbyists who know what they're doing; but that doesn't mean the more expensive "professional" programmers are necessarily better. I found a couple instances where my old Stag programmer wasn't using the correct algorithms or voltages.
There are a couple main Willem variants.
The original versions didn't have a step-up regulator, so you needed to use an appropriate supply. I prefer this variant because it is more reliable for programming older EPROMs that require VPP > 12.5V. The last version from Willem, the 4.1, was the best for NMOS EPROMs (2716, 2732, ...) because it had an optional relay to address the voltage drop from devices that drew more than about 30mA from VCC.
The other variant is PCB3, which introduced the step-up regulator so the programmer could operate from 9-10VDC. A later modification was to add an option to power via a USB port. This variant has all of the problems associated with the original version plus issues with unstable VPP if an improper inductor was used with the step-up regulator. Most variants that I've seen used an inexpensive molded inductor that saturated at a low current.
Later PCB3 variants improved programming speed by changing the way the address was generated and data was read. Those changes have been reverse engineered and any Willem programmer can be modified to use the latest software from Sivava.
Willem was working on a USB version before he passed away that would have been superior to the versions sold by Mcumall. Unfortunately, he never got around to sending me an early version...
The Willem 4.1 seems to be hard to find these days. There was a Chinese company that appeared to have copied the design, but their boards seemed to have problems. I bought a bunch of boards from Willem and still have a few if you're the type who enjoys building your own. Willem's programmers were always more expensive than his competitors. As I recall, he was selling the assembled 4.1 for about $60; which was twice what the other variants were selling for at the time.
Regards,
Dennis
Willem passed away a few years ago.Willem programmers have been mentioned, but willem dot org looks like it was abandoned and picked up by a squatter making money from searches.
Willem programmers are inexpensive and more geared towards hobbyists who know what they're doing; but that doesn't mean the more expensive "professional" programmers are necessarily better. I found a couple instances where my old Stag programmer wasn't using the correct algorithms or voltages.
There are a couple main Willem variants.
The original versions didn't have a step-up regulator, so you needed to use an appropriate supply. I prefer this variant because it is more reliable for programming older EPROMs that require VPP > 12.5V. The last version from Willem, the 4.1, was the best for NMOS EPROMs (2716, 2732, ...) because it had an optional relay to address the voltage drop from devices that drew more than about 30mA from VCC.
The other variant is PCB3, which introduced the step-up regulator so the programmer could operate from 9-10VDC. A later modification was to add an option to power via a USB port. This variant has all of the problems associated with the original version plus issues with unstable VPP if an improper inductor was used with the step-up regulator. Most variants that I've seen used an inexpensive molded inductor that saturated at a low current.
Later PCB3 variants improved programming speed by changing the way the address was generated and data was read. Those changes have been reverse engineered and any Willem programmer can be modified to use the latest software from Sivava.
Willem was working on a USB version before he passed away that would have been superior to the versions sold by Mcumall. Unfortunately, he never got around to sending me an early version...
The Willem 4.1 seems to be hard to find these days. There was a Chinese company that appeared to have copied the design, but their boards seemed to have problems. I bought a bunch of boards from Willem and still have a few if you're the type who enjoys building your own. Willem's programmers were always more expensive than his competitors. As I recall, he was selling the assembled 4.1 for about $60; which was twice what the other variants were selling for at the time.
Regards,
Dennis